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The following research report I wrote for the U.S. Department of Energy, “Biomass Energy, State of the Technology, Present Obstacles and Future Potential”, is long, not well organized, loaded with statistics & boring in places, also full of fascinating (to some...) information, which is at least 20 years old, some dated, some still accurate.  Some biomass fuel sources are now in greater demand in an expanding market, fuel economies are considerably better now, which is also causing ecologically, sociological damaging logging and biomass crop growing.  Biomass energy is ideally suited for local, decentralized, small-scale, efficient cogeneration application, but centralized power holds the inefficient reins of power, temporarily.

Also, more power-generating technologies are now on the market, using biomass fuels, mostly based on thermal gasification.  The report is broken into two sections -- access Section II here, or at the end of Section I below.

This 100-page book also reports on my prototype experiments with integrated gasification/combustion/heat-exchanger furnace designs, compares features, efficiency, emissions, fuel variety, fuel feed considerations, etc., of various furnaces and boilers on the market then, along with an extensive review of regulations helping and hindering the success of biomass energy.  My more recent designs supply a high-quality fuel gas for internal combustion engines and remote appliances as well as hot air and hot water.



State of the Technology

Present Obstacles & Future Potential

A Report for:

United States Department of Energy

Conservation and Renewable Energy

Office of Energy Related Inventions

Prepared by

Larry Dobson

Northern Light Research & Development

(new address) 7118 Fiske Road

Clinton, WA  98236


in Fulfillment of the Terms of

Energy Related Inventions Grant

Project Number DE-FG01-89CE15425

Project Officer: Glenn Ellis

June 23, 1993



The prevailing image of wood and waste burning as dirty and environmentally harmful is no longer valid. The use of biomass combustion for energy can solve many of our nation's problems: waste cleanup, cheap energy as heat and electricity, conservation of fossil fuel reserves, reduction of our foreign debt, increased local employment, retention of energy dollars in the local economy, improved air quality, land reclamation, and retarding of global warming. Numerous factors combine to produce unprecedented opportunities in the field of biomass energy:

· Wood and other biomass residues that are now causing expensive disposal problems can be burned as cleanly and efficiently as natural gas, and at a fraction of the cost.

· New breakthroughs in integrated waste-to-energy systems, from fuel handling, combustion technology and control systems to heat transfer and power generation, have dramatically improved system costs, efficiencies, cleanliness of emissions, maintenance-free operation, and end-use applications.

· Increasing costs for fossil fuels and for waste disposal, strict environmental regulations and changing political priorities have changed the economics and rules of the energy game.

This report will describe the new rules, new playing field and key players, in the hopes that those who make our nation's energy policy and those who play in the energy field will take biomass seriously and promote its use.

History of the Project

The subject and content of this report has been dictated not by the originally projected scope of the project but by the realities of the economic and political climate of this country. This DOE Energy-Related Inventions Grant was applied for six years ago, and much has happened since then. The original task was to build a pre-production prototype 1.5 Million Btu/hr wood-fueled boiler (named Agni) based on the clean combustion and efficient heat-transfer technology developed through ten previous prototypes.

During the initial two years before the grant was awarded to Northern Light R&D, we developed a 150,000 Btu/hr hot air furnace (named "Vaagner") for Vaagen Timber Products Company, the new manufacturing wing of Vaagen Brothers Lumber Company. This residential size system complimented the large industrial wood-waste burner (the Johnson burner) they were manufacturing.

Vaagner evolved from the revolutionary design of "Helen", a sawdust-burning cookstove that officially proved for the U.S. DOE that green wood can be burned as clean as gas. Design, fabrication, and controls were further refined, but the company was loosing its shirt on the Johnson burner and soon dropped out of manufacturing entirely. Vaagner was never commercialized by them, but it proved the soundness of many new design features, indicated new improvements, and allowed extensive development of the microprocessor controls. Vaagner was put through lengthy and rigorous testing, and plans for the larger Agni system were further refined.

Meanwhile, the 40,000 sq. ft. greenhouse which was to be heated by the Agni boiler decided to go out of business, so it became necessary to seek a new site to install the prototype. (This proved to be an elusive 2½ year challenge.) A number of sites expressed interest in heating their facilities with wood waste, but the great expense of installing an automated fuel feed system (which the original greenhouse already had), along with the depressed economic times and concern about future dependability, serviceability and spare parts for an untested prototype, combined to eliminate many of the potential users. Concern about obtaining permits in a political climate hostile to wood burning, and uncertainty about future regulations and dependable fuel supplies in the rapidly changing logging/waste biomass industries also made the sales job tough. We were slowly learning the many obstacles and pitfalls to commercialization.

Pyro industries, the major pellet stove manufacturer in the industry, became enthusiastic about the project and decided to seriously explore the manufacturing and sales potential of the Agni size commercial boiler. They revised the plans for their new 100,000 square foot manufacturing facilities in Burlington, WA to include a hot water heating system and gas-fired boiler, with provisions for the Agni boiler and feed system to be installed within a year. The burner/boiler plans were redrawn to incorporate their manufacturing expertise, and the ceramic heat exchanger castings were redesigned to reflect test data from Vaagner and the new boiler configuration.

Existing fuel feed systems can be 2/3 the cost of an installed burner/boiler/ feed system for the commercial/small industrial market. Because they are too complex and over built for our use, Northern Light designed an automated feed system that can be fabricated and installed for 1/3 to 1/4 the cost of the ones presently available.

The design allows a delivery truck to dump its load straight into a storage area, where it is slowly fed to the fuel hopper by a low-powered "pile feeder" and low-cost conveyor belts. It is designed to handle a large variety of fuel types, including stringy bark and branches, major problems for conventional feed systems.

Still, the board of directors was not convinced that they should launch so quickly into this major new product line, so they commissioned an exhaustive six month marketing/feasibility study. They also requested thorough testing of the Vaagner prototype at the Pyro R&D facilities.

We tested a wide variety of fuels, including refuse-derived-fuel (RDF) pellets and agricultural waste pellets. This yielded more exciting evidence that our technology could handle the least desirable biomass fuels without the problems usually associated with their combustion and with unequaled efficiencies. We also discovered that we could burn wetter fuels than ever thought possible in the industry.

After two years of deliberation and several unforeseen challenges to their corporate health, Pyro decided not to make the required multimillion dollar investment at this time and not to build the Agni prototype. We were greatly disappointed, but all the more convinced by the findings of the marketing study that we had a winner.

Since time was running out on the grant, we decided to pursue the prospect of installing the prototype at a remote penal institute on the Olympic Peninsula. The Clearwater Correction Center was enthusiastic about utilizing locally-available logging waste to save them $30,000 in annual fuel bills, but the state procurement officials were in no hurry to rush the slow steps of bureaucracy. They are still studying the case.

Next, Clean Fuels, Inc., a waste-stream-technology marketing firm in Washington state, became enthusiastic about Northern Light's technology and wanted to fund the production prototype, but their expected financing fell through and they are struggling to maintain their present commitments. Two other very promising options were pursued to no avail within the time constraints of the DOE grant.

Eventually, Northern Light R&D developed a business plan to seek private funding for a limited production run of Agni size commercial combustors and boilers. The figures are very encouraging and we are eager to get on with the project.

We will first build the production-prototype low-pressure hot-water/steam boiler fueled with waste biomass. It will incorporate all of the advanced features described below. We will test emissions from notorious "problem" fuels, such as wet, stringy hogged fuel, sawdust that has been stored out in the rain for years, agricultural wastes, hospital waste, chicken manure, and municipal solid waste (MSW).

Emissions are expected to be well below the most stringent regulations in the nation without expensive stack cleanup equipment. Efficiencies are expected to be above 90% within a very broad power range. Our market study showed this commercial-size to meet the needs of the largest potential market and its production costs to be highly competitive.

Meanwhile, Sunpower, Inc., a major R&D firm specializing in the development of free-piston Stirling engines with linear alternators, approached Northern Light concerning a joint development effort to produce a biomass-fueled residential cogeneration system incorporating their grid-coupling linear alternator and duplex cooler technologies. These engines and coolers use hermetically-sealed helium to transfer externally-produced heat, in this case from biomass combustion, to apply power to the piston.

We are currently assessing the technical merits of Sunpower providing the Stirling alternator, to generate household energy, and their cooler technology, for CFC-free refrigeration and air-conditioning. Northern Light R&D would develop a biomass-fueled combustion/heat-transfer system to power the engines and transfer the remaining heat to the dwelling and its hot water. We are excited about its potential impact on the alternative energy market throughout the world.

Ultimately, a central energy system is envisioned, providing the power, cooking, baking, clothes drying, refrigeration, air conditioning and waste disposal needs of a household. The integrated components of the system would be fully automated to provide efficiencies several times that of separate stand-alone units. Because of superior combustion and heat-exchanger design, a Northern Light Energy System can also burn fuel pellets, oil, natural gas, propane or alcohol more efficiently and cleaner than in commercially available heating systems. The auxiliary fuel can be used for startup and as an automatically switched-on backup fuel.

Northern Light Technology

Cheap biomass fuel is not being utilized primarily because no combustion system is available on the market that is clean-burning enough to pass strict new emission regulations and is also affordable, fully automated, reliable and able to feed and burn the great variety of biomass fuels available, in diverse sizes, composition and moisture content. Northern Light R&D has been working on these problems for twenty years now, and we think we have most of the answers. This unique technology evolved through 10 prototypes which were designed, built, extensively tested, modified and redesigned in a long lineage beginning 20 years ago. Three of the prototypes are still in operation, in service for as long as 10 years.

Throughout this development we have tried to solve the problems of existing technology in the context of real world needs and constraints to optimize efficiency, compactness, cost-effectiveness, durability, and maintenance-free operation. These factors are quite complex, which is why the tremendous opportunity for biomass energy has not been capitalized on sooner, and why this report summarizes all these factors in such detail.


The information used to compile this report comes from over 150 different document sources, as well as a large variety of other sources, including first-hand interviews and Dialog database searches. Much valuable research work has been done in recent years by universities, state energy offices, and most commendably, the U.S. Department of Energy Bioregional Offices. If you find some of the figures quoted conflict, don't be surprised. Considering the fact that we have been in the habit of discarding what we don't use and forgetting about it, it is laudable that so many people are beginning to catalog our wasted resources.

Bibliographical reference numbers are cited at the end of a particular source in brackets.[43] I have sometimes quoted verbatim from the original document. I have taken the liberty to set off in bold type what I consider to be some of the more important points. I have also injected comments freely after quotes {in bold italic brackets.}

The Bibliography was originally compiled alphabetically with 98 references. New sources were continually added, inserted in alphabetical order, with addresses like 45A, 45B, etc.

I apologize for the occasional reference number omitted in shuffling information around. Give me a call if you can't ascertain the source from the bibliography, if you find any erroneous or outdated fact, if you are aware of new and exciting breakthroughs happening in the industry, or you just want to help out the cause, give me a ring at (360) 579-1763, or write:

Larry Dobson

7118 Fiske Rd

Clinton, WA  98236


Energy Equivalents

Throughout this report many figures will be given on volumes, weights and energy equivalents of biomass fuels. To give some feel for the size of these numbers, I will sometimes give an "AGNI" equivalent. This means roughly the amount of biomass fuel that the AGNI boiler would consume over a year operating at 50% capacity day & night, or the amount of fuel that will heat a typical 100,000 sq. ft. uninsulated industrial facility or a 200,000 sq. ft. insulated building using an AGNI Boiler in the Pacific Northwest.

One "AGNI" is roughly equivalent to 7.3 Billion Btu high heat content, 777 tons of green wood/year, 420 Bone Dry Tons (BDT) of most biomass (forest and agricultural), or 2,400 cu. yd. wood chips/yr.

Conversion Factors:

1 Million Btu (1 MBtu) = 293 kW = 29.9 Boiler Hp = 1,000 lb Steam = 120 lb dry wood = 7 gal. Diesel Oil = 1000 cu.ft. (10 Therms) Natural Gas


Biomass Energy

Solar Batteries

It is obvious that the sun keeps our earth warm with its radiant energy. It is perhaps not so obvious that all living and once living matter on this planet is a form of solar battery, storing the suns energy in chemical bonds of air, earth and water, to be later released in a profusion of life processes...or as fire.

When we burn a plant we release the stored water, carbon dioxide and ash along with heat. If we do it right, that's all we get - no pollution. This has been our obsession for twenty years, discovering how to do it right.

Biomass fuel consists of any organic matter available on a renewable basis including forest residues, agricultural crops and wastes, wood and wood wastes, animal wastes, livestock operation residue, aquatic plants, and municipal wastes. Such fuels can provide cheap, clean, efficient and environmentally friendly contributions to the world's energy and waste problems.

A complex interplay of forces have prevented the realization of this potential, and more importantly, continue to retard its development. The U.S. is facing an unprecedented energy/environmental crisis which demands long-range solutions based on detailed knowledge of what is happening in many diverse areas of commerce, government, agriculture, forestry, waste disposal, combustion technology, pollution prevention, and ecology. This report is the culmination of six years of effort pursuing the original mandate of the DOE Energy-Related-Inventions Grant, to commercialize this technology and help meet the nation's energy needs.

I will attempt to show the big picture: the potentials and problems of biomass energy, the solutions that Northern Light and others have developed to solve the problems, and the governmental, attitudinal and marketing constraints to its successful commercialization.

SECTION 1 - an overview. If you want more detail in any area, go to

SECTION 2 - lots of facts , case studies and comments. If you want still more facts, read the appropriate bibliographical references.

Limitations of Fossil Fuels

Reserves Running Out

Natural gas is the preferred fossil fuel of the "clean" 90's, but prices are predicted to steadily rise. Imports from Canada & Mexico will also increase, along with greenhouse gas emissions from burning this fossil fuel. In the U.S., gas is found in only 9 out of 100 natural gas wells drilled, and only 2 of these are of commercial value. The surplus of natural gas that has existed in North America in recent years has driven wellhead prices down to less than the long-term replacement cost in many cases. In the last 2 years, only 65% of U.S. gas production was replaced. As a result, we are close to a balance of supply & demand for the first time in 9 years, and prices should increase.

Extraction costs of oil & coal have also increased, along with the costs of complying with environmental regulations. Major oil companies are finding it much more profitable to invest their resources abroad. The ratio of energy in coal to the energy required to mine the coal has dropped to 59% of what it was 24 years ago. The price of commercial coal in Washington State has increased 238% in 10 years. In contrast, wood chippers use less than 1% of the energy produced, compared to the high extraction and refining costs of coal and oil, often well over 30% of the energy in the final product. Where steam is used to extract heavy offshore crude oils, well over half of the extracted oil is burned to produce the steam. Such wasteful behavior will impoverish our grandchildren. Our valuable fossil reserves are better invested in recyclable plastic and other refinements for future abundance.

Prices Rising for Fossil Fuels, Falling for Biomass

All fossil fuel prices are predicted to escalate at an increasing rate, while costs for biomass fuels such as logging and wood-processing waste, tree trimmings, sawdust, bark, demolition and land-clearing debris, chicken and stockyard manure, orchard prunings, corn cobs and other agricultural field and processing wastes are dropping, as disposal costs rise.

Energy costs for wood residues burned in an efficient Northern Light system are presently only one-eighth of the cost of energy from natural gas in most areas of the U.S., and energy savings are greater yet for biomass residues that would otherwise be disposed of in costly landfills.

Twenty-five billion dollars worth of imported oil could be replaced yearly with the biomass in our nation's municipal waste. The potential exists to supply fifty times this amount of energy from other biomass fuels .


Fuel Costs Chart-93

1993 Energy Costs



Fossil Fuels Cause Global Warming

Scientists now broadly agree that the greenhouse effect is bringing about the greatest and most rapid climatic change in the history of civilization, with enormous consequences for all life on earth. Its primarily cause is the burning of fossil fuels (oil, coal and gas), which dump some 24 billion metric tons of CO2, the primary greenhouse gas, into our atmosphere annually. 750 million metric tons more are added each year.

Each American sends 15,000 pounds of carbon into the air every year, adding up to 22% of the total world-wide carbon release from a country containing less than 5% of the world's population. [World Watch, 6/93]

When biomass decays in a landfill, it generates methane gas, a more potent greenhouse gas than carbon dioxide; it is better all around to burn it rather than bury it. Scientists predict that until we stop burning fossil fuels and begin reversing this trend by increasing the vegetation upon the earth many dire consequences will follow, including inundation of land by a rising sea level, water shortages and crop failures worldwide. Biomass fuels have the potential to reverse this trend when planting levels exceed harvesting. [5B]

Renewable Energy

Biomass Can Replace Fossil Fuels

According to the International Energy Agency, even though biomass conversion provides 15 percent of the world's energy, only one percent of the available biomass is used. Yet biomass meets the direct fuel requirements of a majority of the world's population. Despite the fact that we are now destroying our natural ecosystems faster than we are replanting, there exists a vast untapped global energy resource in annually renewable biomass.

About 3.7%, or 2.7 quads, of all energy consumed in the U.S. today comes from woody biomass, comparable to our use of hydropower and nuclear power.[83A] Various authorities predict that biomass energy from our forest, agricultural, industrial and municipal waste streams can replace from 10% to 90% of our current energy needs. Even in urban areas the biomass produced from land clearing, tree trimming and demolition alone can provide much of the residential heating requirements of the area, rather than disposing of it in ever more costly dumps. According to a 1989 U.S. Department of Energy study, solar and biofuels account for 87.8% of the economically accessible fuels of the future.


CO2 emissions from various electric sources


Biomass Fuels Prevent Global Warming

Fast-growing biomass takes up more carbon than any other process and yields oxygen. In taking into account the total fuel cycle, several studies show that biomass energy is the only option that has a net gain over the carbon/oxygen cycle. Planting trees can reverse the CO2 buildup faster than any other means, and young forests fix more carbon than mature forests. Woody plants capture more sun and are more efficient than annual crops in temperate climates.

Woody crops actually fix over three times more carbon per field per year than a single crop of corn.

Annual crops require annual tilling, which harms the soil by killing not only macroorganisms, but by impoverishing the soil microbiota. During peak sun annual crops have at best only half their photosynthetic surface deployed. Woody plants with rapid early leaf deployment, multiple leaf layers and longer growing season can capture significantly more solar energy than traditional annual crops. Deep roots allow them to continue this even during moderate dry spells. This means more -- potentially much more -- CO2 fixed. The significance for global climate change is profound.

Landfill Debris

In our throwaway society, biomass waste is generally becoming an increasingly costly disposal problem. Landfills are filling faster and faster, and EPA's strict new regulations are expected to cost taxpayers $1 Million per acre to open new ones and force the closing of half of the nation's 5,499 dumps by 1996. From 1/3 to 3/4 of our MSW is biomass suitable for fuel which could replace nationwide 824 Million barrels of imported oil a year.

Urban wood waste processing and delivery services are springing up across the country, charging a tipping fee less than the local landfill for yard waste, tree trimmings, land clearing and demolition debris and reselling chips and compost for a tidy profit. Secondary wood product industries, tree services and agricultural processing industries are looking for alternatives to costly dumping of their residues.


"Recycle" is the buzzword of the '90s because it is generally cheaper and more environmentally sound to do so. Premium grade wood residue can be sold as fiber chips, paper recycled, and yard waste composted. But there is always a large part of our biomass waste stream that is too poor quality to recycle into products. Household garbage and low grade mixed waste paper are better recycled into energy, as long as there is no mercury present to contaminate the exhaust. In the Puget Sound region, 270,000 tons of mixed waste-paper are generated daily from recycling, and much of it landfilled because no one wants it. This would heat 75,000 homes for one fifth the cost of natural gas, and just as cleanly. Even premium grade fiber chips are a quarter to a third the price of gas. Tree trimmings and other woody residues compost slowly and would be much more economically used as fuel.

"Since 1986, 40 states have enacted legislation requiring communities to recycle parts of their waste. The effect has been dramatic. In 1980 the nation recycled only 14 million tons of its MSW and burned virtually none to produce energy. In 1988, 24 million tons were recycled, and 26 million more were incinerated to produce electricity." [62A, 1/92]

Recycling of certain materials continues to increase steadily. The country now recycles 55% of all aluminum cans. While Americans recycle one quarter of the 67 million tons of paper consumed annually, the recycling industry probably couldn't handle the remaining three quarters even if people brought it in. Because demand for recycled paper now roughly equals supply, few recycling mills are being built. [62A]

"The paper recycling process has been refined so that it's inexpensive and efficient. But recycling plastic is expensive, requires a lot of energy, and generates pollution. The furor over juice boxes epitomizes the plastic-recycling predicament: Americans purchase more than four billion of the convenient little boxes each year and recycle almost none. Made of laminated layers of paper, foil, and plastic, these so-called aseptic packages produce pulp of such a low grade that no one wants to buy it." [62A] This material would make excellent fuel in a Northern Light burner.

Communities throughout the U.S. are now accumulating mountains of recycled glass and low grade waste paper with little or no demand for these raw materials. The waste paper, along with other combustibles from municipal waste, is an excellent fuel in our Northern Light combustors to melt waste glass and turn it into useful commercial products.

Northern Light is also developing new technology to recycle glass into durable, lightweight, strong and insulating foamed building products. Currently foamed glass insulation is the monopoly of Pittsburgh Corning, does not utilize recycled glass, and is about three times the price of foamed plastic. Studies show very promising economic viability for such products.

Logging and Agricultural Residue

The amount of unused biomass residue produced in this country is monumental. Most of it doesn't end up in municipal landfills.

MSW is less than 2% of the total available biomass fuel from logging, agricultural harvesting and processing, industrial and municipal waste streams.

In the Pacific Northwest alone, about one quad (1,000 trillion BTUs) of biomass residues are physically generated each year. This is equivalent to 160 million barrels of oil, or $10 billion per year in residential fuel oil. It represents the heat equivalent of 1½ times the annual electric power consumption of the Pacific Northwest. This scenario is repeated across the nation and around the world.

While fossil fuel costs are steadily increasing, the cost of wood fuels is generally declining, with increasing disposal costs for land clearing, logging cleanup, yard trimmings, and mill waste. A BPA study, Regional Logging Residue Supply Curve Project, states,

"Current indications are that recovery and transportation costs for any given piece size will decline...In no case can it be shown that there will be a significant rise in wood fuel prices for the remainder of this century."

"American demand for wood continues to rise, yet the nation's forests are growing faster than they're being harvested. In 1990, logging companies planted some 41.9 billion seedlings, according to the American Forest Council (AFC)." [22]

Dr. Harold E. Young calculated Maine's wood resources, based on utilizing the whole tree, and compared them with the U.S. Forest Service's figures, which are based only on the merchantable bole (excluding tops, needles & leaves, branches & roots). The annual production of the complete forest is 8.75 times as great as the merchantable bole harvest! This impressive number gives some indication of the increased potential for energy from logging waste.[22]

Biomass Farming

Energy crops are seriously being considered as an alternative to fossil fuels, sparked by environmental concerns about conventional forestry practices, the Clean Air Act, global climate change, soil conservation and energy needs. While only 15,000 to 20,000 acres of short-rotation woody crops are planted in the U.S. today, the feedstock potential could easily lead to more than 20 gigawatts of new capacity by 2010.

Jerry R. Allsup, director of DOE's Office of Alternative Fuels, Transportation Technologies, Conservation & Renewable Energy, says the agency "believe(s) that (wood's) role in energy is likely to grow in the future because of an increased research effort to produce faster growing trees, better utilization of the existing stands of energy and a renewed effort to utilize wood waste for energy as a part of better integrated resource planning." [Alternative Energy Retailer]

In Minnesota, short rotation intensive culture (SRIC) of trees can produce 3 to 6 dry tons/acre/year, as compared to yields of 1 dry ton/acre/year in native forest stands.[Pamphlet published by University of Minnesota, Office of Biomass Research, 10/91]

Hemp cultivation can produce 8 to 24 BDT/acre/year. Sugar cane and some tropical crops yield 40 or 50 tons per acre. [45]

Crop set-aside programs, conservation programs, emission taxes & air quality non-attainment areas have helped energy crops to become marginally competitive in some areas. Delivered energy crop production costs are now estimated at about $39 to $63/dry ton.

Energy crops could be planted on the 200 million acres of underutilized and marginal agricultural land in the United States. [62B] Much of this land could be improved with the proper balance of biomass plantations, while at the same time generating a large renewable fuel supply. BACH (Business Alliance for Commerce in Hemp) claims that if only 5% of the nation's land were devoted to hemp, it would supply all the energy, and that land doesn't even have to be arable."

Sweden demonstrates the economic viability of biomass energy. The country plans to double its present reliance on wood energy in the next decade, providing 28% of its energy needs largely from fuelwood plantations surrounding decentralized power plants located in each community.

Biomass Energy Saves Dollars, Creates Local Jobs

The most expensive biomass fuel, premium grade fiber chips for paper making and chipboard, costs only one third as much as Texas intermediate crude oil at the pump and one fourth the price of commercial natural gas for the same energy content. Typical fuel-grade biomass is often one eighth the cost of fossil fuels, delivered. Additionally, Northern Light biomass energy systems extract more heat from the fuel than most fossil fuel fired systems.

By substituting Municipal Solid Waste (MSW) for imported oil, we could save an estimated $25 billion a year in foreign exchange, while at the same time creating thousands of new jobs locally and saving $10 Billion on landfill costs.

The economic benefits in other areas of biomass energy are much greater. Energy investments stay in local communities; workers of varied skill levels can be employed. Industrial wood energy utilization in the Southeastern Region of the U.S. is projected to generate approximately 97,000 jobs and $1.4 billion annually by the year 2000.

Political Climate Improving

State and regional governments are waking up to the manifold possibilities of a local waste-to-energy infrastructure to provide jobs, keep energy investments from leaving the state, solve waste disposal problems and eliminate air pollution from slash and field burning. Programs to inform businesses of the advantages of biomass energy and to fund demonstration and research projects are being developed nationally and locally. The vast potential for biomass farming is receiving more and more serious consideration and funding. The net gain in the greenhouse cycle has the capacity to preserve our planet, and a growing wave of environmental concern may push biomass energy into the forefront of future energy options.

"I'm hearing from the marketplace, " says Stan Sorrell president and C.E.O. of the Calvert Group of mutual funds, "and what I am hearing is that environment is and will be the main issue of the nineties." [The Nation, 3/26/93]

Environmental Regulations Demand Better Technology

Recently, tough environmental laws passed by the EPA, notably the Clean Air Act, Clean Water Act, new landfill regulations, and Woodstove Performance Standards, have dramatically changed the playing field in the biomass energy game. State and local regulations have compounded the effect in many areas.

"Changing landfill regulations have a decided impact on the availability of mill residues. More stringent disposal standards increase the cost of disposal forcing mill operators to explore additional options including potential fuel applications. Currently, some sawmills are finding disposal costs so expensive that they may be forced to close down. This situation is partially responsible for the low current (1990) price of mill residues. In fact, some mills are paying a fee to energy users to dispose of their residues. They do so because the landfill disposal costs are even higher. This is another case where environmental policy can make more material available for energy uses."[6]

The new Clean Water Act will indirectly provide significantly more biomass feedstock and need for incineration of wastes that are now polluting ground water in landfills and storage dumps. Candidates include poultry and chicken litter, manure from dairies and feedlots, onion culls, chicken carcasses, etc.[77] Because Northern Light's burners can handle such diverse wet fuels, they should serve this market well.

Title XIX of the Energy Policy Act of 1992 included tax provisions to encourage investment in renewable energy sources, including biomass. The Energy Act also provides a 1.5 cent tax credit for every kilowatt-hour of electricity produced from "closed-loop biomass" (crops grown exclusively to produce electricity).

The U.S. Department of Energy, Office of Utility Technologies, is enthusiastic about biomass energy. [62B]

"The future for biomass power looks particularly attractive given the potential for substantially expanding biomass supplies by growing new energy crops on millions of acres of underutilized land; the potential for significantly improving the performance of biomass power technologies through R&D; important environmental benefits offered by biomass power such as recycling of atmospheric carbon and its low sulfur content; as well as the potential for biomass power to provide substantial rural economic development benefits.

The growing demand for electricity, in conjunction with a new regulatorycompetitive environment and environmental pressures such as those created by the clean air act, has created a substantial target of opportunity for biomass power over the next decade. The 1980's provided a decade of technological progress to build upon."

"The plan of the DOE Biomass Power Program is to make the 1990's a decade of commercialization. The strategy is to develop advanced high-efficiency biomass power systems with competitive feed stocks and to capitalize on Clean Air Act requirements and state environmental actions."

Much more governmental support needs to be directed toward these ends than is now in the budget. Sweden has taken biomass energy seriously, and is now spending as much on R&D in this area as is the entire United States. "At the heart of Sweden's program is public support. Enlightened, environmentally-conscious citizens and an elected body free from the domination of nuclear and fossil fuel lobbyists have been essential for the progress to date." [83A]

Permits Need to be Streamlined

Regional regulatory officials tend to be suspicious of poorly performing old-technology wood-fueled systems. This makes permitting difficult and time-consuming. In contrast, numerous officials in the Department of Energy, the Environmental Protection Agency, and State Energy Offices are anxious to see such clean, efficient technology as Northern Light has developed commercially available. Government funding is available for extensive emissions testing, and with the support of the EPA and DOE, local permitting should become easier than at present.

Biomass Energy - The Problems

Negative Perception

Surprisingly, this increasingly favorable renewable energy alternative is not being capitalized on and few people are even aware of it. In fact, general public and governmental attitudes are often decidedly negative. Influential environmental groups, such as The Sierra Club and Friends of the Earth, equate wood burning with noxious emissions and environmental degradation. They maintain that garbage and processing waste should either not be generated in the first place or should be recycled. Energy conversion is not considered recycling, yet the facts show it to be a better option than burning of 40 million year-old fossilized biomass, at least for the next few decades until energy becomes cheaply available without using fuel. Even then, there will always be byproducts of human endeavors that can best be disposed of by burning, and where heat is needed, combustion is the most direct approach to getting it, outside of direct solar radiation.

The New York State Energy R&D Authority gave up on trying to get any large wood-fueled installations permitted. Public sentiment is against "incineration" of any kind, and burning wood waste is seen in the same light as municipal waste.

The Northwest Power Planning Council has dismissed biomass as a potential future source of energy. In fact, in their 40 page draft plan (vol.I), only two sentences are devoted to biomass, and its projected contribution to the regional power pool is only 0.6% of the total! Cost and public sentiment seem to be keys to that decision.

Heat from waste wood in the area can directly replace electric heat - at one ninth the cost. This is not currently being factored into the Regional Power Plan, despite the fact that already one fifth of all Washington State households heat their homes with both wood and electricity, displacing up to 1,000 MWa of electric power in the region. [41A, 6] In other parts of the country, the cost advantage of wood heat over electric heat is more like 30 to 1 and rising.

Instead, 76% of the new power sources under development in the region are generators that run on natural gas, a fuel imported primarily from Colorado and Alberta. Yet the quantities of biomass residues produced each year in the region are equivalent to 7,600 MW of electric generating capacity, almost twice NPPC's projected new generator capacity requirements to the year 2010!


The standardization and coordination of regional and national regulations for biomass-fueled boilers is complicated by several factors:[80]

* Each state may require different levels of emission control to satisfy their State Implementation Plan.

* Each state has a different level of industrialization.

* Each state may pursue promotion of energy resources most abundant in their area.

* The impact of emissions varies with terrain and climatic factors.

"While the potential for conversion to wood-energy is high, fossil fuel sources will remain prominent in some areas as long as the current state regulatory scenario is perceived to be detrimental."[80]

There has been major reduction in the number of new wood-waste combustion systems installed in the Puget Sound region in the last 7 years. Much of this is due to (1) state regulations to discourage residential woodstoves and (2) Puget Sound Air Pollution Control Authority's (PSAPCA) strict 1990 emissions regulations on new wood-fueled boiler installations. The latter regulations allow new systems to emit only a tenth of the particulates that the older systems are permitted. This has prohibited small to medium sized installations of any waste-wood-fueled system now on the market because of the extremely costly cleanup equipment required to achieve compliance (cyclone separators, baghouse filters, electrostatic precipitators, etc.). Even the new state-of-the art 46 megawatt biomass power generating facilities in Kettle Falls, WA, just barely meets this standard.


PSAPCA 1990 particulate emission regs


Despite great improvements in residential woodstove design over the past 7 years, Most people assume that wood can never be burned cleanly. Wood smoke has become synonymous with pollution in official circles as well. A joint report by the State of Washington and the U.S. Environmental Protection Agency, "Toward 2010: An Environmental Action Agenda", recommends that Washington State "Phase out residential wood-burning stoves and inserts." The logic is that, "A decade or so ago, heating a home with wood was considered a clean alternative and an answer to the energy crisis. Today, residential wood burning is widely recognized as one of the most significant sources of air pollution--especially of small particulates--in our state."

There seems to be little interest in the results of a study commissioned by the local Bonneville Power Administration, Environmental Impacts of Advanced Combustion Systems, which proved that a residential cookstove designed by Northern Light R&D burned wood 65 times cleaner than the average woodstove and cleaner than most oil and gas fueled residential furnaces, without contributing to the greenhouse effect. The disturbing destruction of our remaining virgin forests has totally overshadowed the fact that forests can be a renewable crop and that large quantities of biomass waste of all kinds are continuously being produced and need to be disposed of.


Woodstove Emissions-1990 EPA


Fuel Nature & Availability

Biomass fuels are produced wherever plant material is harvested, processed or used, generally in millions of decentralized locations throughout the country. They exists in such varied location and form as logging slash, agricultural crop residue, stockyard manure, food processing remains, demolition debris and cabinet maker scraps. No national distribution system is possible. Biomass fuels are locally generated and must be locally utilized to be cost-effective. While this has economic advantages, it does not lend itself to centralized coordination, and therefore is not so attractive to large corporations and governmental bodies.

Local processing and hauling operations are springing up wherever waste has become an expensive disposal problem, but a well-established and dependable fuel delivery service does not exist in many areas, simply because there has not been the customer base of biomass fuel users.

Without an existing fuel delivery infrastructure, potential customers are reluctant to invest in a biomass energy system. This situation also dissuades potential investors, manufacturers and marketing firms from getting involved in the biomass energy game. The prevailing attitude is, "Let the industry get further developed...Then I will get involved." Now is the time for government and industry to make major investments in the future of a decentralized biomass energy industry to get it established and over the initial hurdles.

Fuel Handling

Fully automated fuel feed systems are expensive. Currently available fuel feed systems are individually designed and fabricated for the logging industry. They are too complicated, over built, and expensive for such small-scale systems as we have determined to be the best market. This has been a major factor in preventing greater utilization of bioenergy on the commercial scale. A fully automated fuel storage/feed system of present design could make up two thirds of the total cost of an installed commercial wood-fueled boiler system of Agni size. Such an investment is not cost-effective in today's short-term investment market. Northern Light R&D has done considerable research in this area and has developed a simple system which should drop the cost by 50 to 75%. Additional funding will be needed to perfect the most economical fuel feed system and open up the market to the widest customer base.

Defects of Available Technology

All indications point to a very promising future for bioenergy, but the industry is not yet prepared with answers to the many perplexing problems confronting the would-be customer. Equipment is complex, costly and too often plagued with aggravating problems and limitations. Variations in fuel type, size and moisture content are not easily accommodated in any one combustion/fuel-handling system. Much of the potential fuel is too wet, too stringy, not uniform enough in size and moisture content or too high in ash and dirt content for existing systems to handle at all. Most biomass combustion systems available at present have a very narrow range of clean combustion, with a turn-down ratio of only 2 or 3 to 1. This makes them inappropriate for many applications that have seasonal variations in heat demand.

All wood-burning boilers on the market today have difficulty meeting increasingly strict emissions regulations without costly stack clean-up air pollution controls. Typical flue gas scrubbing and conditioning equipment costs average from 25 to 40% of the total capital costs of coal-fired plants and consume large amounts of power (approximately 3% of the total unit output). [Biologue, Dec'88/Jan'89]

Fuels with moisture content higher than 40% have unacceptable emissions problems, and nothing currently available can even burn fuel above 66% moisture content. Yet there are huge outdoor stockpiles of wood-waste throughout the country that are wetter than that. Because all of the moisture in the fuel is vaporized and sent up the stack, net system efficiencies drop to unacceptable levels with high moisture fuels.

Controls are generally very basic and incapable of analyzing changes in multiple variables to self-correct imbalanced conditions and optimize combustion conditions. None except the very largest industrial installations even monitor fuel/air ratios.

A boiler with fully-automated feed system is so expensive that it has not been cost-effective in sizes below 10 million Btu/hr, but this size represents the largest customer base. For a heating system the size of Agni (1.5 MBtu/hr) a fully-automated feed system could amount to 75% of the total installation cost.

If, in addition to a hassle-free fully automated feed system one requires a sophisticated microprocessor control system for feed, combustion, boiler monitoring and control, with multiple alarms; automated ash-removal; the capacity to automatically handle various low-grade fuels; a high turn-down ratio; very low emissions to meet strict governmental standards; and high efficiencies even with wet fuels; they will find nothing on the market at any price.

But most of these problems have been solved and extensively tested in the 10 prototypes Northern Light R & D has developed over the past 20 years. The remaining challenges have been addressed in the most recent improvements to the Agni design, and in new approaches to inexpensive fuel handling described at the beginning of this paper.

Defining the Market

The experts seem to agree that, at the present time, the best way to recycle wood waste is to convert it to energy by combustion. There is not a sufficient demand for alternative uses such as composting or animal bedding to absorb the large amounts of wood waste produced in the U.S. The primary forest products industry is already doing a good job of generating its heat and process steam requirements through the combustion of its wood waste. The secondary forest products industry could generate a good deal more of its heat and process energy needs by wood combustion. Beyond that, the potential market is determined by numerous factors that have been well researched for the economics and capacities of presently available systems.

Four market studies have been carried out in different areas of the country to define the existing and potential users of commercial and industrial wood fueled boilers.[5], [48], [48A], & [77]

The SERBEP 1986 study [5], "Analyzing Market Constraints in Woody Biomass Energy Production", determined that there were about 5843 reported industrial wood energy users in the continental U.S.. A 1977 study [80] reported about 10,500 wood-fired boilers installed nationally. The discrepancy can be attributed mostly to the fact that close to half of these were smaller than industrial size. In 1977, wood-fired boilers represented only one-third of one percent of the total national boiler installations. Approximately 76% of fossil fuel boilers installed in the United states are rated at below 1.5 million Btu/hr.

The largest market for wood-fired boilers is below 1.5 MBtu/hr, but this is generally below the cutoff considered cost effective for presently available systems and below the size of concern to half of the studies. Yet this is the most appropriate market for decentralized collection and distribution of biomass wastes and application of the Stirling engine linear alternator technology for cogeneration.

The SERBEP study [5] identifies five important constraints preventing wood energy use in the Southeast:

  • 1. a general lack of knowledge concerning industrial wood energy and a poor perception regarding its application
  • 2. high capital costs of conversion to a wood energy system
  • 3. problems associated with wood fuel handling
  • 4. concern over dependable long-term supply
  • 5. lack of knowledge about the proper operation of a wood energy system

A major constraint identified by this study is a lack of knowledge about industrial wood energy and a poor perception towards its implementation.

The lack of confidence in the availability of outside sources of wood, of funding for conversion to wood, and of incentive to convert to wood (as well as industries requiring outside wood sources) are speculative reasons for the slow growth of the wood-fired boiler population. Costs of conversion to a wood energy system is perceived as the most significant barrier.[5]

Today, conversion to a wood energy system may be two to seven times the capital cost for an oil or natural gas energy system, and twice the capital investment of a coal energy system. Fuel handling costs are a significant part of this high initial investment. However, Northern Light R&D has developed a much simpler low-cost option for automatic feed.

A study in South Carolina [77] concluded that if the cost per million Btus from wood residue is at least $3.65 less than the cost from fossil fuels, conversion for a minimum or larger industry becomes a real possibility. However, these figures were based on very costly feed system and boiler installation costs and on 65% boiler efficiencies, rather than the 90%+ efficiencies of a Northern Light system.

This means that the wood residue prices can be 38% more for the same energy yield. Taking representative commercial fuel prices from the Pacific Northwest as an example, natural gas is around $4.44/MBtu, which would give an appropriate cost for wood waste at $1.09/MBtu. The most expensive wood chips are delivered in the area for $0.94/MBtu. Therefore, even for presently available wood-fueled boilers and costly feed systems, wood energy is a profitable investment in the region.


Looking at the potential for residential cogeneration, we have a different set of economics. If a home or apartment energy system produces electricity and replaces a central heating system, hot water heater, cookstove, and perhaps also supplies refrigerator cooling and air-conditioning, hot air for the drier, and waste disposal, a more expensive system could be cost-effective. Adding up all the costs of the individual appliances that are replaced and their combined energy costs show a major investment indeed. This potential deserves serious R&D work.

Best Size System

Because biomass fuel is available in decentralized locations, and transportation costs are a big factor in both disposal costs and potential fuel delivery economics, small commercial systems afford significant advantages.

There are over 1480 landfills in the 13-state Southeast Region. 55% of these are small (<30,000 cu.yd./yr.). In MS, WV, KY, and GA there are 537 small landfills and only 3 large (600,000 cu.yd./yr.). If one third of the waste going to these landfills can be cleanly burned for energy, the average size of incinerator needed by most Southeastern counties would be less than 10 MBtu/hr. If a more decentralized cogeneration siting approach were taken, even smaller units would be appropriate.[72]

One Agni-sized boiler (1.5MBtu/hr) could serve a community of 1,500 people. (@ 5,000 Btu/lb with recycled beverage containers removed, and about 33% moisture.)

Small biomass combustion systems can have permitting advantages. In some areas, permitting for larger systems (over 12 tons/day) is much more difficult, due to classification as a potential industrial pollution source.

"Small, hospital-sized incinerators such as the Therm Tech in Fairbanks (Hospital) could provide opportunities for using solid waste to heat community buildings or schools in rural Alaska. Small communities in Alaska are experiencing difficulties in properly disposing of MSW, particularly where high water tables and lack of suitable cover cause landfill problems. Most waste-to-energy facilities use incinerators that are large, continuously fed systems that are too big for small communities. An incinerator the size of the Fairbanks unit could process 2.5 tons of solid waste per day on two shifts, providing adequate disposal for a community of 1,000 people." [3]

BioBurn Corp. of Utica, NY, is a sales representative and distributor for over ten different manufacturers of solid fuel combustion equipment ranging from 50,000 Btu/hr to 1000 boiler horsepower. They are constantly seeking and testing new equipment to find a good range of systems that can meet the needs of different users. They contend that there is no wood chip combustion equipment under 100 hp (3.3 MBtu/hr) that is both economical and technically reliable. [93]

This observation is echoed by numerous authorities in the field. The report, "Stack Emission Standards for Industrial Wood-Fired Boilers" [80], concludes,

"After review of the current situation, it is apparent that efforts to promote wood energy use is best directed to small boilers. In addition to representing over 90% of the total number of boilers, the 0-1.5 million Btu per hour capacity boiler, and small (less than 10 million Btu per hour) regulated boiler, offers the following advantages for conversion to wood-firing:"[80]

* "The greatest number of wood-fired boilers are fueled using residue generated by production at the facility. This residue does not have to be hauled off-site, thus reducing the deleterious effects of other contributors of pollution e.g. fugitive dust. There are few large facilities which generate sufficient wood residue to be energy self-sufficient."[80]

* "Wood-fired boilers fired with residue from the production facility are immune from wood shortages and fuel transportation problems."[80]

* "Small wood-fired boilers are easily switched to fossil fuel firing in an emergency situation compared to larger boilers of the same design and operation."[80]

* "Small boilers will have minimal impact on the local ambient air quality singularly or cumulatively (assuming normal distribution of small boilers). This conclusion is supported by modeling results."[80]

* "Small boilers will not impact local wood fuel supplies (assuming normal distribution of small boilers)."[80]

* "Small boilers are best suited for retrofit and are the most flexible compared to large boilers of similar design and operation."[80]

"Other findings of this study include:

* "A correlation between the wood-fired boiler population in a state and the state's particulate emissions standard is not readily apparent."

* "Potential users of biomass are not aware of the availability of wood, the operation of wood-fired systems, the applicable air pollution regulations, or the permitting process."

* "Efficient operation of the boiler and associated equipment will also result in the lowest emission rates."

* "Innovative methods of operation can eliminate the requirement for air pollution control equipment or at least reduce the cost of control equipment."

Each statement is supported by detailed discussion in the report.[80]

Greatest fuel savings and payback within 2 years can be realized in commercial installations such as greenhouses, hospitals, schools, county seats and other public buildings, laundries, factories, wood- and agricultural-processing facilities, shopping centers, hotels, resorts, and nursing homes, wherever there is nearby biomass waste and space to store the fuel.


Small, efficient, cost-effective cogeneration systems fueled with biomass promise the greatest near-term potential for solving the world's energy needs of any available renewable energy option. The energy and environmental crisis we are facing on all fronts has forced us Americans to reevaluate our "mega" approach to problem solving. Utilities are suddenly looking to conservation and efficiency as an alternative to building more power plants. Decentralized electric power cogeneration is preferred to wasteful large central power plants. We must use less, use it more efficiently, reuse it again and again. The operating principles are Conserve, Reuse, Recycle.

Applying these principles to energy and waste recycling, we must conclude that small decentralized settings are the best cogeneration sites.A community could recycle local biomass, household waste and low grade paper into energy for a recycling operation, providing heat, mechanical power, and electricity for transforming recycled glass into foamed building insulation and roofing tiles, for an aluminum foundry, pottery and glass blowing studios, etc.. The waste heat, too, could be recycled first back into the combustion air, then into process steam or used in a Laundromat, car wash, sauna, heated swimming pool or greenhouses.

By recycling waste biomass into energy, recycling waste energy back into the combustion process, and using the waste heat again and again, increases in efficiency are possible that are many times what is presently achievable.

According to the Union of Concerned Scientists, "Buildings use more than one-third of the energy consumed in the United States. Heating and cooling systems account for 60% of this energy." Of that amount about 20% is reasonably recoverable with the use of appropriate heat engines. This amounts to about 15% of the electricity requirement of the country.[37A] There are 54 million single-family dwellings in the U.S. which could take advantage of cogeneration to generate much of its power from the nation's waste .

Electric utility customers at the end of the power grid are losers for the power company. Electricity that makes it to the end may be 15% less than the power sent out of the power plant, which in turn is only about a third of the energy stored in the fuel. It would be far more efficient to generate electricity right at the remote site, with no transformer or line losses, using most of the remaining valuable heat energy for space heating, hot water, etc., by burning locally generated and continually renewable biofuels. Economical, reliable residential cogeneration systems are the key, and this is what Northern Light & Sunpower are currently investigating.

Municipal Solid Waste

MSW has become a major disposal problem worldwide, and burying it is no longer a viable solution. Incineration has just as bad a reputation, despite the costly gas cleanup technology employed. Part of the pollution problem is poor combustion (Dioxins, Furans, PAHs, PCBs, etc.), and part of the problem is heavy metal and other contaminants. With proper source separation, heavy metals can be eliminated from most waste streams. Poor combustion requires in most cases an entirely new combustion approach. Pyrolytic gasifiers are much better technologies in this regard, but they are too costly and complex for small municipalities.

MSW incinerator plants presently tend to be very large (200 - 3000 tons/day) because of the complexity and cost of the equipment, but there are significant advantages to small, decentralized installations:

1. Waste is mainly produced in local, decentralized homes and businesses. Shorter hauling distances mean reduced disposal costs.

2. MSW is a valuable fuel which can best be burned in numerous smaller decentralized locations where heat and processing steam can be utilized, along with cogeneration.

3. Large garbage-collection sites have traffic congestion, odors, large volumes of emissions, and strong public opposition.

4. Many municipalities do not generate enough waste to support a large, expensive disposal installation.

There needs to be more thought and support given to the clean conversion of municipal waste to energy in small, decentralized community settings. Existing systems are prohibitively expensive and unreliable. Because Northern Light's technology is so clean and simple and capable of handling such a diversity of fuels, it should be ideally suited for such application.

The Biomass Energy Research Association (BERA) recently testified before the House Committee on Science, Space, & Technology, Subcommittee on Environment,

"In combustion research, a need still exists for improved solid waste incinerators that meet environmental requirements and cost goals. Research should be focused on systems that can be used for economic disposal of MSWs in small communities. Research is also needed to reduce the emissions of solid waste disposal processes..."

Northern Light R&D has done this research and has come up with a number of major improvements. Gasification and combustion processes are separated by preheating to very high temperatures the fuel and the air for pyrolysis and combustion and by controlling primary and secondary air through a microprocessor linked to various sensors and dampers. This allows extremely wet material of diverse physical properties to be burned completely without carrying ash and other particulate out the stack. In tests burning RDF (Refuse-Derived-Fuel) pellets, excess air was brought down to ½%, while maintaining low carbon monoxide emissions (0.02%). This is unprecedented in biomass combustion. Only large state-of-the-art gas furnaces approach such efficiencies.

Further advantages to this staged combustion approach are reduced NOx emissions and elimination of ash-slagging problems associated with low melting temperature ash from MSW and agricultural fuels. This latter problem has plagued the industry and is aggravated by the larger system approach.

The smokeless, odor-free exhaust is further scrubbed of fly-ash in the condensing boiler, where moisture from the fuel is precipitated out as clear water. There is no need for the costly stack clean-up equipment currently used in the industry. Because the whole system is so elegantly simple, it should be able to meet the disposal and heating needs of small municipalities at one quarter the cost of systems now on the market and easily pass the most stringent emissions regulations.

Emissions Chart-particulate from boilers

Wood Burns Cleaner Than Oil.

A prototype residential cook stove developed by Northern Light R.&D. (named "Helen") was officially tested by OMNI Environmental Laboratories for the U.S. Department of Energy/Bonneville Power in 1986, burning green sawdust of 44% moisture content, with no catalytic afterburner or stack cleanup of any kind. [40]

Its particulate emissions were 65 times cleaner than the average state-of-the-art woodstove, several times cleaner than the best pellet burner, and considerably cleaner than the average oil furnace.

Carbon Monoxide emissions in the stack gases were 1/7500th of the Federal Auto Emissions standard, 1/100th of the gas industry's standard for "CO-free combustion", and 1/2 of the EPA's standard for acceptable 24 hour indoor air quality.


CO emissions chart


These emissions are less than half of the most stringent PSAPCA standards for new wood and refuse burners. Since this prototype, two improved versions have been built.

The most recent 150,000 BTU/hr hot air furnace (Vaagner) is capable of burning the wettest wood (logs, chips, sawdust, etc.) extremely cleanly and efficiently. Primary and secondary air is precisely controlled by a state-of-the-art microprocessor continually monitoring input from various temperature and position monitors and an oxygen sensor in the exhaust stream.

Flue gases are usually so cool that clear water is condensed out in the heat exchanger. This reclaims the heat of vaporization and allows wet fuels with over 70% water to be burned as efficiently as dry ones. No other combustion system yet tested comes close to this capacity. (The condensate poses no disposal problems in sewers or septic tanks. It contains no sulfur and is less acid {pH 4.5} than rainfall near many fossil-fueled industrial areas of the world {pH 3.5}) The unit can be fitted with a large hopper to hold several day's fuel at one loading. It will also burn pellets cleaner and more efficiently than commercial pellet burners, and can be operated without electricity if necessary.


Excess Air Requirements02


Heat Transfer Chart
Most commercial systems presently available in any size produce unacceptably smoky emissions and drastically reduced efficiencies when operated at half or third of rated output. In contrast, Northern Light furnaces burn as clean, and with higher net efficiencies (over 95% with wet fuels!) when turned down as low as 7% of full power output (14 to 1 turndown ratio). No other system can even approach this versatility. This feature alone opens up a much greater market than ever before for biomass energy applications.

State-of-the-art Silicon Carbide heat exchanger transmits heat to the incoming combustion air 6 to 10 times as fast as firebrick. Extremely strong, durable, fatigue- and shock-resistant refractory ceramics are used in the combustion areas, High-temperature ceramic fiber insulation is used along with concentric heat-exchanger shells to move the heat where it is needed to optimize pyrolysis and combustion and to eliminate excessive heat which produces slag buildup and ceramic fatigue.

Counterflow gravity-stratified condensing heat-exchangers, specifically designed for high-ash biomass fuels, scrub the exhaust & reclaim the heat of vaporization of the moisture in the fuel. Thereby wet fuels can be burned as efficiently as dry. The thermodynamic properties of these heat-exchangers increase natural draft and eliminate the need for exhaust fans (and their tendency to send unburned embers, soot and ash to clog up the heat-exchanger and increase particulate emissions). All soot is burned in the combustion zone. The remaining fly-ash is removed from the exhaust stream through a combination of centrifugal/gravity precipitation and steam-condensation entrainment, which continuously scrubs the lower heat-exchanger surfaces. We have built hot air and hot water systems and have designed a low pressure steam boiler.

A gravity feed hopper operates when the power is out and takes any size, shape and configuration of fuel without hang-ups. Counterweighted hopper flaps prevent uncontrolled combustion and heat loss in the upper hopper. They also indicate status of fuel reserves, turn on fuel feed in automatic feed systems, facilitate smoke-free loading of the hopper. The lower hopper is vertical sided with no constrictions to hang up stringy hogged fuel or logs.

We have developed a powerful but inexpensive central microprocessor control system with built-in analysis and correction routines and an alarm system. In both the commercial Agni system and the residential cogeneration system it will control the fully automated feed system, automatic ash removal system, and dual-fuel switching functions.

With the new fuel feed system, the economics of the installed package is very favorable compared to natural gas, and no contest when replacing oil or electricity. We expect to offer a complete Agni 1.5 MBtu/hr system, with condensing boiler, fully automated computer control, ash removal and fuel handling systems for under $90,000 installed. Eventually, with the development of an even more economical feed system and optimizing of all the components in the system, the total package installed cost could be substantially less.


To continue reading Part II of this report, CLICK HERE







Unit 200 cubic of uncompacted volume

Green Unit (GU) - Chips Weighs approximately 3,430 Lbs @ 30% MCWB

Bone Dry Unit (BDU) Used as a basis for payment for pulp chips. A measure of weight, not volume, defined as 2,400 Lbs @ 0% MC.

Green Ton (GT) 2,000 lbs of woody material, as received and includes the weight of water in the material.

Bone Dry Ton (BDT) 2,000 Lbs of woody material @ 0% MC. - The most accurate measure for energy purposes.

Wood density Range for Western softwoods, 23 to 28 lbs/ft3 @ 0% MC. Varies with species and location.

Cord Stack of wood, 4'x 4'x 8' or 128 gross cubic feet (usually about 80-90 net cubic feet but varies widely with log diameter)

Board foot (BF) A measure of the volume of wood fiber in lumber Lumber scale form nominally equal to 1/l2th cubic foot.

Board foot (BF) There are many varieties of log scale measuring

Log scale systems. Converting BF log scale to BF lumber scale depends upon the log scale system.

One Log Truck Load Approximately 5,500 BF, log scale.

Log Weight 1,000 BF, logs, log scale, has a weight range of from 6,463 lbs to 10,262 lbs depending upon species.

When converted to residue, 1,000 BF yields 2 units of a combination of chips, sawdust, and hog fuel.


Moisture content can be measured on a wet or a dry basis. In engineering calculations moisture content (MC) is usually expressed as a percent of the total weight. This is the wet basis method. In forest product calculations, the dry basis method is used; the moisture content is expressed as a percent of the dry weight of the wood. Thus:

MC (% Wet Basis) = (Water Weight) / (Total Weight) x 100

MC (% Dry Basis) = (Water Weight) / {(Total Weight) - (Weight of Water)} x 100

If M & D represent the moisture contents on the moist-wood and dry-wood bases respectively, then:

M = D / (1 + D) and D = M / (1 - M)






1 KWhr


1 Cubic Foot Gas


1 Therm Gas


1 lb Bituminous Coal


1 lb Charcoal


1 Gallon #2 Diesel Oil


1 Gallon Propane


1 Ton Whole Tree Chips


(50% moisture)

8.3 to 8.8 MBtu

1 quad




1 Boiler Horsepower

33,475 (33,472)


= 9.8095 kW

1 Btu (British Thermal Unit)

= 0.29307 watt

1 million Btu (1MBtu)

= 293.07 kW

1 lb of steam/hr

= 0.2843 kW

1 lb of steam

= 1000 Btu


Moisture Content Heating Value Bulk Density

Wood Fuel Wet Basis (Btu/lb) (lbs/ft3)

Whole tree chips 50% 4000 24

      " 45% 4800 23

Green sawdust 50% 4000 20

Dry planer shavings 13% 6960 6

Dry sawdust 13% 6960 11

Wood pellets 10% 7200 35

      " 8% 8000 45

* Source: The Industrial Wood Energy Handbook, 1984.

* Second Source: Wood Burning for Energy [92]

Throughout this report many figures will be given on volumes, weights and energy equivalents of biomass fuels. To give some feel for the size of these numbers, I will sometimes give an "AGNI" equivalent. This means roughly the amount of biomass fuel that the AGNI boiler would consume over a year operating at 50% capacity day & night, or the amount of fuel that will heat a typical 100,000 sq. ft. uninsulated industrial facility or a 200,000 sq. ft. insulated building using an AGNI Boiler in the Pacific Northwest.


  • *Alternative Sources of Energy Magazine Minigrant, 1977
  • * Washington State Energy Office, grant, 1987-88
  • * Vaagen Timber Products Company, assistance in prototype development, 1988
  • * U.S. DEPARTMENT OF ENERGY, Energy-Related Inventions Grant, 1989-1993



  • * Proceedings of the Weltkongress Alternativen und Umwelt, Vienna, 1980, A High Efficiency Home Energy System Burning Biomass
  • * Alternative Sources of Energy Magazine, 1980, The Grendle Report
  • * The Mother Earth News Guide to Home Energy, 1980, An Amazingly Efficient Sawdust Stove
  • * International Bio-Energy Directory and Handbook, 1984
  • * Proceedings of the 1986 International Conference on Residential Wood Energy, High-Tech Non-catalytic Woodstove Design Considerations
  • * Proceedings of the 1988 Washington Wood Utilization Conference,A State of the Art Woodchip Boiler


for Footnotes and Further Information

{Footnote Numbers Correspond to Source Numbers}
{Key Categories in Italics}

  • 1. 1990 Wood Residue Survey and Directory of Secondary Wood Processing Facilities in Washington State, Washington State Energy Office, 9/90.
  • 1A. 1991 Northwest Conservation and Electric Power Plan, Volume 1, Northwest Power Planning Council
  • 2. A Model Resource Recovery & Conservation Plan for Northwest Missouri State University, Northwest Missouri State University, 10/89, On integrated recycling, resource recovery, and conservation efforts at Northwest Missouri State University, Environment, Fuel Source
  • 3. Alaska Energy Authority Bioenergy News, a monthly newsletter, Good case-studies and up-to-date regional information
  • 4. An Overview of Wood Energy in the Southeastern United States, P.C. Badger & C.D. Stephenson, Southeastern Regional Biomass Energy Program, 6/89, Good detailed overview, Wood Energy
  • 5. Analyzing Market Constraints in Woody Biomass Energy Production, Timothy M. Young & David M. Ostermeier, Southeastern Regional Biomass Energy Program, 9/86, Final Report, Customer, Fuel Source, Competition, Regulation
  • 5A. Ash Deposition During Coal and Biomass Combustion, Larry L. Baxter, Combustion Research Facility, Sandia National Laboratories, Livermore, CA, Presented at the Biomass Combustion Conference, Reno, 1/92
  • 5B. Atlas of the Environment, Geoffrey Lean,, Prentice Hall, 1990
  • 6. Assessment of Biomass Resources for Electric Generation in the Pacific Northwest, James D. Kerstetter, Ph.D. Washington State Energy Office for Northwest Power Planning Council, 1990, Wood Energy, Electricity, Fuel Source
  • 7. Assessment of Biomass Resources for Florida, Final Report, Southeastern Regional Biomass Energy Program, 1985?, Fuel Source, Survey
  • 8. Auger Combustor for Chicken Litter, Dennis R. Jaasma, Southeastern Regional Biomass Energy Program, 12/87, Fuel Feed, Fuel Source, Combustion, Competition
  • 8A. BIO Conversion--Fuels from Biomass, E.E. Robertson, executive director of the Biomass Institute, Winnipeg, Manitoba, Canada, 1977
  • 9. Bioenergy Brief, a monthly newsletter, Pacific Northwest & Alaska Regional Bioenergy Program
  • 9A. Bioenergy Projects Degest; Materials Handling 1984-1989, A review of Bioenergy Materials Handling R&D projects funded by Energy, Mines and Resources, Ottawa, Ontario, Canada, 1990
  • 9B. Biofuels, Air Pollution, and Health, a Global Review, by Kirk R. Smith, 1987, Plenum Press, NY.
  • 10. Biologue, and the Regional Energy Program Reports, Official Publication of the National Wood Energy Association, published quarterly --- very informative and up-to-date, Regulation, Fuel Source, Conference, Customer
  • 10A. Biologue Article, May/June,'91: "Renewable Energy Boosted by Iowa Utilities Board"; Electricity
  • 11. Biomass Design Manual, Industrial Size Systems, Southeastern Regional Biomass Energy Program, 9/86, Covers wood-fired boiler, emphasis on larger than 8.5MBtu/hr, bibliography, glossary and list of fuel brokers, suppliers, and equipment manufacturers, Boiler/Heat-exchange, Competition, Fuel Feed, Emissions
  • 11A. Biomass Energy: A Monograph, Edited by Edward A. Hiler & Bill A. Stout, 1985, Texas Engineering Experiment Station, Texas A & M University Press.
  • 12. Biomass Energy Facilities, 1988 Directory of the Great Lakes Region, Great Lakes Regional Biomass Energy Program, 1988, Survey, Wood Energy, Customer, Fuel Source
  • 12A "Biomass Energy: The Forgotten Fuel", Biologue, May/June' 91, Panel of experts discuss present & future trends. 1989; Dr. Ralph Overend-manager SERI Biomass Power program; Robert P. Kennel-constructs & operates large scale biomass facilities; Dr. Mark C. Trexler-energy & environmental consultant, World Resource Institute; Leonard Theran-pres. G&S mill.
  • 13. Biomass Energy Project Development Guidebook, John M. Vranizan,, Pacific Northwest & Alaska Regional Bioenergy Program, 7/87, "..written for managers, engineers, and financial officers in business, industry, and government so that they might investigate the feasibility of using biomass fuels," Fuel Source, Case Study, Customer
  • 14. Biomass Energy Systems: A Preliminary Investment Decision-Making Guide for the Small Business, Southeastern Regional Biomass Energy Program, 1/88, Includes 'BIOVEST', 1989 economic assessment software for Lotus 1, 2, 3. The sample calculations seem to be faulty on p.7 - Using a 4,000 BTU/lb heat value for 50% moisture wood along with a 67% boiler efficiency results in a system efficiency of 31% - this seems too low, creating an unfairly high steam cost. Economics
  • 15. Biomass Energy, A Resource Assessment, Western Regional Biomass Energy Program, 10/87, Survey, Wood Energy
  • 16. Biomass Estimates for Five Western States, James O. Howard, Pacific Northwest & Alaska Regional Bioenergy Program, 10/90, Fuel Source, Environment
  • 16A. Biomass-Fired Steam-Injected Gas Turbine Cogeneration, by Eric D. Larson & Robert H. Williams, Princeton University
  • 17. Biomass Fuel Characterization: Testing & Evaluating the Combustion Characteristics of Selected Biomass Fuels, Final Report, Dwight J. Bushnell, C. Haluzok, Abbas Dadkhah-Nikoo, Oregon State University, for Bonneville Power Administration, 9/89, Combustion, Fuel Source, MSW, Emissions
  • 18. Biomass Fueled Stirling Engine Combustor Research, W.H. Percival,, United Stirling Inc., Alexandria, VA, 1982?, Electricity
  • 19. Biomass News, a monthly newsletter, Western Regional Biomass Energy Program
  • 20. Biomass, International Directory of Companies, Products, Processes & Equipment, J. Coombs, Macmillan, Stockton Press, 1986, A British Publication - expensive, but good source of broad spectrum of
  • 21. Boilers Fired with Wood and Bark Residues, David C. Junge, Ph.D., Oregon State University School of Forestry & Plywood Research Foundation, 11/75, Combustion, Boiler/Heat-exchange, Emissions
  • 22. Burning Wood for Energy, Negative Perceptions & State of the Art Facts, Nancy R. Holmes, NRH Associates, Inc., Swanton, VT, 11/91, She is very interested in our work, Fuel Source, Environment, Emissions, Boiler/Heat-exchange
  • 23. California Biomass Facilities Directory Survey, Final Report, NEOS Corporation, Calif. Energy Commission & Western Regional Biomass Energy Program, 3/91, All large electricity-generating plants, Electricity
  • 24. Case Studies of Biomass Energy Facilities in the Southeastern U.S., Meridian Corporation, Southeastern Regional Biomass Energy Program, 8/86, Good crossection of installations, Customer, Boiler/Heat-exchange, Competition, Fuel Feed
  • 25. Catalytic Gasifier/Combustor for biomass Fuels, D.R. Jaasma,, Southeastern Regional Biomass Energy Program, 9/86, Combustion
  • 26. Central Biomass Combustion Facility Feasibility Study, Charles, Crane, MERDI, Inc., for, Montana Department of Natural Resources & Conservation, 7/82, Fuel Source, Customer
  • 27. Clean Air Washington, Washington State Department of Ecology, A set of publications explaining the Clean Air Washington Act of 1991, the problems and regulations to assist solutions.
  • 28. Cogeneration Feasibility Study, Comparison of Rankine Vs Stirling Engines Adapted to a Solid Fuel Combustor, Robert J. Boucher, Montana Department of Natural Resources & Conservation, 11/83, Electricity, Wood Energy
  • 29. Cogeneration from Biofuels: A Technical Guidebook, James L. Easterly, P.E., & Dr. Michael Z. Lowenstein, Meridian Corp. for Southeastern Regional Biomass Energy Program, 9/86, Electricity, Fuel Source, Regulation, Wood Energy
  • 30. Combined Cycle Biomass Energy Research Project, Final Report, Task 4: Resource Assessment; Part 1, Executive Summary, James W. Funck,, Department of Forest Products, Oregon State University, 9/86, Very detailed, county-by-county assessment in full report, would be useful for sales staff., Fuel Source, Wood Energy
  • 31. Demand for Wood Residue by Kiln Drying Enterprises in the Central Appalachians, Final Report, James P. Armstrong & Samuel M. Brock, Southeastern Regional Biomass Energy Program, 10/87, Customer, Fuel Source, Survey
  • 31A. Design and Performance of Wood-Chip-Fired Stokers and Pre-Heaters (output range 25 - 75 kW), Prepared for Technology Branch, Energy Mines and Resources, Canada, 1988
  • 32. Design Manual for Small Steam Turbines, Gerald R. Guinn, Ph.D., Southeastern Regional Biomass Energy Program, 3/90, Electricity
  • 33. Directory of Biomass Installations in 13 Southeastern States, Southeastern Regional Biomass Energy Program, 12/86, All-inclusive, but not much detail or analysis of results, Survey, Customer, Wood Energy
  • 33A. Economic Impact of Harvesting Wood for Energy, James E. Johnson,, Great Lakes Regional Biomass Energy Program, 3/87
  • 34. Economic Impact of Industrial Wood Energy Use in the Southeast Region of the U.S., Volume I: Summary Report, Meridian Corporation, Southeastern Regional Biomass Energy Program, 11/90, Wood Energy, Survey
  • 35. Economic Impact of Industrial Wood Energy Use in the Southeast Region of the U.S., Volume II: Data Collection Methodology & Databases, Meridian Corporation, Southeastern Regional Biomass Energy Program, 11/90, Comes with Lotus spreadsheet program, Fuel Source, Customer, Environment, Regulation
  • 36. Economic Impact of Industrial Wood Energy Use in the Southeast Region of the U.S., Volume III: Model Description, Meridian Corporation, Southeastern Regional Biomass Energy Program, 11/90, A description of the computer-based model used in study, Wood Energy, Survey
  • 37. Electronic Control of Wood Combustion, David W. Guernsey, U.S.D.O.E., 11/82, Combustion
  • 37A. Energy for Planet Earth; Special Issue of Scientific American, Vol. 263, No.3; 9/90
  • 38. Energy From Crops and Agricultural Residues in Montana, Howard E. Haines, Montana Department of Natural Resources and Conservation, 8/87, Fuel Source, Biomass Farming
  • 39. Enhancement of Output of a Wood Burning Gas Turbine with Water/Steam Injection, Joseph T. Hamrick, Southeastern Regional Biomass Energy Program, 11/87, Work done at Aerospace Research Corporation, Combustion, Electricity
  • 40. Environmental Impacts of Advanced Biomass Combustion Systems, Final Report, OMNI Environmental Services, Inc., for, U.S.D.O.E., 1/88, Report of emissions from 'Helen' prototype built by Mr. Dobson, Emissions, Combustion, Case Study, Wood Energy
  • 41. Environmental Impacts of Harvesting Wood for Energy, James E. Johnson,, Great Lakes Regional Biomass Energy Program, 3/87, Biomass Farming, Environment
  • 41A. Evaluating Effects of Wood Smoke Control Legislation in Washington State on Electrical Customers, prepared for Bonneville Power Administration by Mile Nelson,, WSEO, 6/90
  • 42. Evaluating Recently Developed Two-Stage Combustion Technology for Small-Scale Application, Frederick A. Payne, Southeastern Regional Biomass Energy Program, 8/85, Combustion, Case Study
  • 43. Evaluation of Potential for Electrical Generation Using Solid Waste as Fuel in the Pacific Northwest, Gershman, Brickner & Bratton, Inc., with, Systems Architects Engineers for, Bonneville Power Administration, 6/83, Electricity, MSW
  • 44. Final Report on Biomass Technology Transfer Studies, Robert W. House & Robert T. Nash, Southeastern Regional Biomass Energy Program & TVA, 5/85, Addressing potential for using more wood for energy, what potential customers, fuel harvesting, handling, storage, combustion, How to promote & encourage this energy use., Fuel Source, Customer, Regulation
  • 45. Garbage, The Practical Journal for the Environment, see article in Nov/Dec/91 issue, "Great Green Hopes"
  • 45A. The Gaia Atlas of Future Worlds, by Norman Myers, Gaia Books Ltd, London 1990
  • 46. Hogged Wood Fuel Supply and Price Analysis, Final Report, Richard T. Biederman & Christopher F. Blazek, Institute of Gas Technology, for Bonneville Power Administration, 5/91, For Pacific Northwest Region, comes with a Lotus spreadsheet forecast model for the PC, Fuel Source
  • 47. Implementation and Management of an Alternative Fuel System Through Private Funding in a Public Assisted Institution, Dwight, Branson & Robert E. Bush, The Missouri Department of Natural Resources, 5/84, Case Study, Boiler/Heat-exchange, Biomass Farming
  • 47A. Industrial/Commercial Wood Energy Conversion, a Guide to Wood Burning, Fuel Storage & Handling Systems, Great Lakes Regional Biomass Energy Program, 1992?
  • 48. Industrial Wood Energy Information Survey, Final Report, Harold, King, Great Lakes Regional Biomass Energy Program, 5/86, "The purpose of this survey was to obtain a better understanding of the information needs of businesses and public institutions in the Great Lakes region that may convert to wood fuel as their primary energy source." Customer
  • 48A. Industrial Wood Fuel Market Assessment in Washington State, James D. Kerstetter, Ph.D., Washington State Energy Office, in Proceedings of energy from Biomass and Wastes X Conference, April, 1986
  • 49. Industrial/Commercial wood Energy Conversion, A guide to Wood Burning, Fuel Storage & Handling Systems, Great Lakes Regional Biomass Energy Program, 1987?, good glossary, Boiler/Heat-exchange, Fuel Source, Fuel Feed, Emissions
  • 50. Mill Residue Availability in Montana, Montana Department of Natural Resources and Conservation, 1986, Fuel Source, Wood Energy
  • 51. Montana Bioenergy Publications, Montana Department of Natural Resources and Conservation, 6/89, Good bibliography of regional studies & statistics
  • 52. Montana Biomass Cogeneration Manual: A Workshop Handbook, Dilip R. Limaye & Shahzad Qasim, Montana Department of Natural Resources and Conservation, 5/83, Electricity, Wood Energy
  • 53. Montana Bionotes, Summaries of Biomass Energy Projects funded by the, Montana Department of Natural Resources & Conservation, 1986?
  • 54. Montana's Bioenergy Project Permitting Guidebook, Montana Department of Natural Resources & Conservation, 7/86, Regulation
  • 55. Municipal Solid Waste to Energy Analysis of a National Survey, For Washington Communities Interested in Energy Recovery as an Alternative to landfilling MSW, James D. Kerstetter, Washington State Energy Office, 6/87, MSW
  • 56. Municipal Waste Combustion Study, Costs of Flue Gas Cleaning Technologies, U.S.E.P.A., MSW
  • 57. Municipal Waste Combustion Study: Characterization of the Municipal Waste Combustion Industry, Radian Corporation, U.S.E.P.A., 6/87, MSW, Survey
  • 58. Municipal Waste Combustion Study: Flue Gas Cleaning Technology, Charles B. Sedman & Theodore G. Brna, U.S.E.P.A., Office of Solid Waste, 6/87, MSW, Emissions, Survey
  • 59. Municipal Waste Combustion Study: Report to Congress, U.S.E.P.A., 6/87, MSW, Regulation
  • 60. Municipal Waste Combustion Systems Operation and Maintenance Study, U.S.E.P.A., 6/87, MSW, Combustion
  • 61. National Wood Energy Survey, Final Results, Timothy M. Young & David M. Ostermeier, Department of Forestry, Wildlife & Fisheries, U. of Tennessee, Study done for SERBEP, Survey
  • 62. Northwest Energy News, a bimonthly publication by the, Northwest Power Planning Council
  • 62A. OMNI magazine, 1/92
  • 62B. "Opportunities for Biomass Power", by Dr. Robert San Martin, Deputy Assistant Secretary, Office of Utility Technologies, Office of Conservation & Renewable Energy, Department of Energy, presented to First National Fuelwood Conference, 11/91
  • 63. Pacific Northwest and Alaska regional Bioenergy Program Yearbook, 1984 to present, Excellent summary of regional activities and future emphasis of DOE bioregion programs
  • 64. Pacific Northwest and Alaska Regional Bioenergy Program, Five Year Report: 1985-1990, Pacific Northwest & Alaska Regional Bioenergy Program, 2/91, Wood Energy, Regulation
  • 64A. Paper Recycling: The View to 1995, Franklin Associates & the American Paper Institute, 2/90, MSW
  • 65. Permits-Regulations-For Biomass Energy Facilities in the Southeast, Richard E. DeZeeuw,, Southeastern Regional Biomass Energy Program, 8/86, Includes detailed maps showing non-attainment areas, class I PSD areas, and detailed state requirements & contacts; glossary, Regulation
  • 66. "Plan Ahead to Avoid Feeding Problems", David H. Wilson & Donald L. Dunnington, Chemical Engineering, 8/91, Good overview of materials-feed technology, Fuel Feed
  • 67. Planting & Growing Trees for Energy: the Historical Perspective, J.W. Ranney, Environmental Sciences Division, Oak Ridge Nat. Lab., U.S.DOE, 11/91, Biomass Farming
  • 67A. Power, the Magazine of Power-Generation Technology, Dec./91
  • 68. Proceedings of the 1985 Biomass Thermochemical Conversion contractors' Meeting, Pacific Northwest Laboratory, U.S.D.O.E., 10/85, Conference in Minneapolis attended by Mr. Dobson
  • 69. Proceedings: Pacific Northwest Bioenergy Systems: Policies and Applications, Pacific Northwest & Alaska Regional Bioenergy Program, 5/10/84, A seminar attended by Mr. Dobson, Regulation, Wood Energy
  • 70. Proceedings: Washington Wood Utilization Conference, Sponsored by, Washington State University, 3/88, A conference in Fife, WA, attended by Mr. Dobson, Conference
  • 71. Productivity of Forests of the United States and Its Relation to Soil and Site Factors and Management Practices: A Review, Charles C. Grier,, U.S. Department of Agriculture, Pacific Northwest Research Station, 3/89, Biomass Farming, Survey, Environment
  • 72. Regional Assessment of Nonforestry-Related Biomass Resources, Summary Volume, JAYCOR, Southeastern Regional Biomass Energy Program, 3/90, Includes Appendix D: Significance of Food Processing By-Products as Contributors to Animal Feeds, Phase I, Food Processing Survey. Fuel Source, Survey, Biomass Farming
  • 73. Regional Logging Residue Supply Curve Project, Volume 1 - Final Report, Envirosphere Company, Pacific Northwest & Alaska Regional Bioenergy Program, 8/86, Table of Contents & Summary only, Fuel Feed
  • 74. Resource Assessment of Waste Feedstocks for Energy Use in the Western Regional Biomass Energy Area, K. Shaine, Tyson, Western Regional Biomass Energy Program, 2/91, WAPA Project BF983232 Evaluates the near term potential of waste feedstock supplies, specifically agricultural residue and waste paper for ethanol production, for each county in WRBEP area.
  • 74A. Secrets of the Soil, "Biomass Can Do It"
  • 75. Science & Technology In Review, Quarterly news magazine of, Solar Energy Research Institute, (SERI), Summer/91
  • 76. Short-Rotation Intensive Culture of Woody Crops for Energy, Principles & Practices for the Great Lakes Region, Meridian Corporation, Great Lakes Regional Biomass Energy Program, 1986?, 12/10
  • 77. Small-Scale Bioenergy Alternatives for Industry, Farm, and Institutions: A User's Perspective, Proceedings of the National Bioenergy Conference, U.S.D.O.E., University of Idaho, & Idaho Dept. of Water Resources, 3/18/91, Conference
  • 78. Solid Waste Management Alternatives, Buncombe County, North Carolina, Final Report, HDR Techserv, Inc., Southeastern Regional Biomass Energy Program, 1/88, MSW
  • 79. Southeastern Regional Biomass Energy Program, Six Year Report: 1983-1989, Southeastern Regional Biomass Energy Program, 11/90, Good state-by-state survey & annotated bibliography of SERBEP publications, Wood Energy, Regulation, Survey
  • 80. Stack Emission Standards for Industrial Wood-Fired Boilers, Final Report, Roy F. Weston, Northeastern Regional Biomass Energy Program, 1984, Detailed description of APC equipment on p.6-3 through p.6-36, extensive bibliography, a Regulation, Customer, Survey
  • 81. Status of Industrial Wood-Fueled Systems, P.C. Badger,, American Society of Agricultural Engineers, 6/87, general overview, Wood Energy, Boiler/Heat-exchange, Fuel Source, Fuel Feed
  • 82. The Development of a 1 kW Electrical Output Free Piston Stirling Engine Alternator Unit, David M. Berchowitz, Sunpower Inc., Athens, Ohio, 8/83, Electricity
  • 83. The Expected Influence of Biomass in the British Columbia Energy Sector to 2010 AD, Forestry Canada, Pacific & Yukon Region, Pacific Forestry Center., 1991, Fuel Source, Environment, Regulation. Information collected 1988.
  • 83A. Trees for Fuelwood: A Step Toward Energy Diversity, Edited by James R. Fazio, 1993, The Arbor Day Institute, 100 Arbor Avenue, Nebraska City, NE 68410
  • 84. Trees for Energy: First National Fuelwood Conference, Arbor Day Institute, 11/11/91, Notes from talks, handouts at conference, Conference, Biomass Farming, Environment, Fuel Source
  • 85. Turndown Ratio of Two-Stage Combustors, P.K. Chandra & F.A. Payne, Southeastern Regional Biomass Energy Program, 1985?, Combustion, Case Study
  • 86. Two-Stage Biomass Combustion for Direct Drying Applications, P.K. Chandra, Southeastern Regional Biomass Energy Program, 1986?, Combustion
  • 86A. Use of Biomass Energy by Non-Forest Product Facilities - Case Studies, Prepared by Gerald Fleischman, P.E., Idaho Department of Water Resources, Energy Division, Boise, Idaho, 3/91
  • 87. User's Manual, Economic Feasibility Assessment for an Agricultural Biomass Furnace System, Agricultural Engineering Department, Montana State University, 2/86, describes a user-interactive computer program that helps an agricultural producer decide if a biomass-fueled system (straw, etc.)for drying grain or heating a structure may be economically feasible for a particular operation, compared with conventionally-fueled system. Includes appendix G: Research, Design, & Construction of controller to mix drying air.
  • 87A. U.S. Industrial Outlook '92, U.S. Department of Commerce, 1/92
  • 88. Utilization of Biomass to Dry Whole Corn, Mark A. Little, Montana Department of Natural Resources & Conservation, 10/84, Case Study, Customer, Fuel Source
  • 89. Vortex Gasifier Burner and the EZY FLOW Dryer/Metering Bin, Summary Final Report, ALA-TENN Industries, Inc., for, Southeastern Regional Biomass Energy Program, 1985, Wood Energy, Case Study
  • 90. Washington Directory of Biomass Energy Facilities, James D. Kerstetter, Ph.D., Washington State Energy Office, 8/87, Fuel Source, Customer, MSW
  • 90A. Washington State Biomass Data Book, Joyce A. Deshaye & James D. Kerstetter, Ph.D., Washington State Energy Office, 7/91, WAOENG 91-10,, the most up-to date information on biomass resources, energy use & future potential, (Along with the 1990 Wood Residue Survey and Directory of Secondary Wood Processing Facilities in Washington State [0A]), bibliography, glossary, and sample of detailed county profile (All the detailed county reports have been obtained as well from WSEO), Fuel Source, Customer, MSW
  • 90B. Waste-To-Energy Systems, A Great Lakes Casebook, prepared by J.K. Cliburn & Associates for the Great Lakes Regional Biomass Energy Program, Council of Great Lakes Governors, 1/92
  • 91. Weight, Volume, and Physical Properties of Major Hardwood Species in the Upland-South, Alexander, Clark III,, Southeastern Forest Experiment Station, 11/86, Fuel Source, Biomass Farming
  • 91A. Whole Earth Review,Winter 1992, "Kill More Trees; As Fast As Possible" by Philip A. Rutter Badgersett Research Farm RR 1/Box 141 Canton MN 55922 (Hazelnuts & chestnuts)
  • 91B. Wood Ash Composition as a Function of Furnace Temperature, Mahendra Misra & Keneth Ragland, Dept. of Mechanical Engineering, University of Wisconsin-Madison.
  • 92. Wood Burning for Energy, Case Studies from the Great Lakes, Abby, Feely, Great Lakes Regional Biomass Energy Program, 9/86, good glossary, Customer, Boiler/Heat-exchange, Fuel Feed, Fuel Source
  • 93. Wood Chips: An Exploration of Problems & Opportunities, E.C. Jordan Co. & Maine Audubon Society, Northeastern Regional Biomass Energy Program, 1984, Good list of fuel dealers & furnace manufacturers, Fuel Source, Competition, Customer, Fuel Feed
  • 94. Wood Energy Guide for Agricultural and Small Commercial Applications, Larry G. Jahn, Southeastern Regional Biomass Energy Program, 10/85, Good cost figures & equipment vendors, Customer, Boiler/Heat-exchange, Fuel Feed, Fuel Source
  • 94A. Wood Energy Information Guide, R. N. Elliott, North Carolina Agricultural Extension Service, North Carolina State University, 1984
  • 95. Wood for Fiber Products and Fuel, a Diminishing Supply?, Charles E. Keegan & Mary L. Lenihan, Montana Department of Natural Resources and Conservation, ?, Fuel Source, Wood Energy
  • 96. Wood Waste Energy Incentive Program, Summary Report, Wisconsin Energy Bureau, 9/90, Customer, Fuel Source
  • 97. Wood Waste Review, a newsletter by the, Iowa Department of Natural Resources, 6/90
  • 98. Wood-Fueled Processes & Equipment, Georgia Institute of Technology, Georgia Office of Energy Resources, 5/80, Concentrates on gasifiers, Combustion, Boiler/Heat-exchange, Biomass Farming
  • 98A. World Congress - Alternatives & Environment - Proceedings, Vienna, United Nations World, 1980



  • * Energy from Biomass and Municipal Waste, U.S.D.O.E., 1/88, Current abstracts: Prepared by Office of Scientific and Technical Information.
  • * Five Year Research Plan 1988-1992 Biofuels: Renewable Fuels for the future, EPA/600/D-91/053, U.S.E.P.A., 1988, OCLC# 19804606, Report #DOE/CH10093-25 The paper discusses a portion of EPA's global climate change program, a program plan for methane climate change program, especially research efforts on global landfill methane.
  • * "Fuel Handling and Storage," W.S. Bulpitt & J.L. Walsh, Jr., The Sixth International Forest Products Research Society Industrial Wood Energy Forum, Proceedings 7334, 1982.
  • * Guide to Oregon's Environmental Permits for Biomass Energy Projects, sponsored by the Oregon dept. of Energy
  • * Handbook for Conversions to Wood Energy Systems, "a technical publication that may be of interest to administrators and plant managers of facilities considering conversion to wood fuel systems." Council of Great Lakes Governors, Great Lakes Regional Biomass EnergyProgram, 122 W. Washington Avenue, Suite 801A, Madison, WI 53703
  • * Incineration of Solid Waste, C.C. Lee, et. al., U.S.E.P.A., Cincinnati, OH, Risk Reduction Engineering Lab., 1989, The objective of the paper is to review the fundamentals of incineration (combustion) and to provide an incinerator design example to show how combustion fundamentals are applied to an incineration system.
  • * State Biomass Statistical Directory - $12.50 from NWEA
  • * The Industrial Wood Energy Handbook, 1984 (or more recent if available), prepared by the Georgia Institute of Technology, write to Council of Great Lakes Governors, Great Lakes Regional Biomass EnergyProgram, 122 W. Washington Avenue, Suite 801A, Madison, WI 53703
  • * "Municipal Solid Waste: a Resource Assessment for energy Recovery in Alaska", & Annual Report, highlighting activities of Alaska Bioenergy Program 7/90-6/91, free from Rick Rogers, Alaska Energy Authority, PO Box 190869, Anchorage, AK 99519-0869, (907)561-7877
  • * MICHIGAN Wood & Waste Fuel User Survey & Waste Exchange Services. To receive copy of final survey report, (including all users of wood, municipal, & ag. wastes) contact Michigan Biomass Energy Program 517/334-6264 or write care of tom Stanton, MBEP, Michigan PSC, P.O. Box 30221, Lansing, MI 48909 - ORDERED Nov 1, 1991
  • * Three scheduled research projects: "Emissions Data for Wood Waste Fuel Containing Non-Wood Material", to be conducted jointly with the other 4 regional programs. & the NY. Energy Off. "Wood Manufacturing Directory" "Ash Testing" of ash from 50 - 100% wood & wood waste fuels. Reported in Biomass Energy Program Report, Great Lakes Region; Biologue, MR/AP'91
  • * DATABASE; WRBEP (Western Regional Biomass Energy Project) is developing a database of companies offering biomass-related services & products for the 13 state area be completed...summer '92? Contact Pat McCann, 303-980-1969
  • * "Wood Waste Energy Incentive Program a Success"; governmental summary: 19 new wood systems were installed in Wisconsin with grants. From Biologue article, May/June ,'91.
  • * "SERBEP Industrial Wood Fuel Economic Impact study Revised"; Economics Of Biomass Energy In Southeast Region. Summary From article in Biologue, May/June, '91.
  • * KSU to Develop Agribusiness Database that will characterize and catalog sources, types, and volumes of agribusiness processing residues generated within the state of Kansas. contact Dr. Richard Nelson, Energy and Waste Specialist, Engineering Extension, or Dr. Rolando Flores, Food Engineering Specialist, Agricultural Engineering, KSU, (913) 532-6026