THE CASE AGAINST INTENSIVE FOREST MANAGEMENT IN MAINE

THE CASE AGAINST INTENSIVE FOREST MANAGEMENT IN MAINE http://www.forestecologynetwork.org/BANDY22.htm

by LeRoy Bandy, PhD and Barbara Bandy, M.S.

For references and more information, consult the Bandy's bibliography on clearcutting.

The forestland of Maine is sometimes referred to as the Northern Hardwood-Coniferous Forest, a forest type that is a mixture of tree species found further to the south, with those more prevalent further to the north.

Some of these species include softwood coniferous types such as red, black, and white spruce, balsam fir, white pine, hemlock and cedar. Also common to the Maine forests are hardwoods such as beech, red maple, sugar maple, aspen, and yellow and white birch. The proportions of these various species vary from location to location depending on soils, slope and altitude.

Forest Fires and Windthrows are Very Rare

A common misconception about the Maine forestland is that disturbances such as frequent large-scale fires and windthrows are a natural part of our forests here. Actually, a scientist named Lorimer in the 1970s published research in which he had analyzed land survey records that covered over 4 million acres of Maine for the period from 1793 to 1827. From these records he was able to determine that the average recurrence interval for fire for a given site would have been 800 years.

Large-scale windthrows were even more infrequent, occurring on average every 1,150 years for a given site. Thus, the forests of Maine, prior to European settlement, were not subject to frequent large-scale disturbances, although that misconception continues to be spread by those who advocate “clearcutting as a form of harvesting that mimics natural disturbance”.

Forest Soils

There are many important components of a healthy forest ecosystem. We can begin by looking at the soil. The forest soil contains nutrients, many microorganisms, tiny creatures that feed on and break down the leaf litter, and somewhat larger creatures such as salamanders that are important parts of the food web. The way trees are harvested can affect all of these components.

For example, scientists at the USDA Forest Experiment Station in Durham, N.H., analyzed data from six different sites in the eastern United States, including sites in Maine and New Hampshire. They concluded that calcium is in danger of being depleted from forest soils, due to the combined effects of acid rain and whole-tree clear-cutting on 40-year rotations.

Magnesium and potassium are also in danger of depletion. Whole-tree harvests remove the entire above-ground portion of trees, including the tops, which contain more than half of the nutrients. Nutrients also leach from the soil after it is exposed by clear-cutting.

Research in Maine has shown that sixteen years after a whole-tree harvest, an area that was clearcut has 25% less organic matter in the soil than adjacent unharvested plots. The level of organic matter in the soil is important for nutrient cycling, water-holding ability, and other properties important for plant growth.

Data from the same research site has shown that whole-tree clearcutting has caused long-term disruptions in nitrogen cycling, and potential depletion of phosphorus. In addition to nutrient loss, research at the Hubbard Brook Experimental Forest in New Hampshire showed that aluminum ions in levels toxic to fish and other aquatic organisms were released into stream waters draining clearcut sites.

These effects on water chemistry persisted for three to four years after the clearcut harvest. Unfortunately, some of the large industrial landowners are making extensive use of this method of harvest. Champion International for example, is using whole-tree clearcutting on short rotations on forty percent of its lands in Maine, or approximately 360,000 acres.

Beneficial Fungi in Forest Soils are Damaged by Clearcutting

Among the many important microorganisms in the forest soil are mycorrhizal fungi. Mycorrhizal fungi form associations with the roots of trees and enhance tree growth in various ways. It has been known for some time that these fungi can form networks between the roots of different trees, even between trees of different species.

Recently, researchers in British Columbia made an important breakthrough in understanding the ecological significance of these fungal-tree communities. They showed that seedlings of Douglas fir grown in the shade of paper birch received a net transfer of carbon from the birch trees through the fungal connections. This research shows that in a natural forest ecosystem, trees such as paper birch, considered a "weed" species by foresters, may nourish other tree species such as the commercially valuable Douglas fir.

These complex interactions may help stabilize the forest ecosystem in the long run and help protect against extremes of moisture, temperature, and against insect outbreaks and disease. Unfortunately, intensive forest management techniques such as clearcutting and herbicide spraying disrupt these complex and beneficial associations between trees and fungi.

Small Animals in the Forest

Many small animals in the forest soil play important roles in the decomposition of organic matter and nutrient cycling. As they feed on dead organic matter and soil microorganisms, they contribute to soil fertility and improve soil porosity. Tiny insects and mites, known collectively as microarthropods, are among the typical small animals found in forest soil. In one study, researchers found that whole-tree clearcutting resulted in a significant decrease in the number of soil micro-arthropods, when compared to less-intensive harvests in which not all trees were cut, and the tops of cut trees were left on the ground. This was probably due to the decrease in organic matter and soil moisture, as well as the extreme temperature conditions found on the clearcut sites.

Salamanders in the Forest

Salamanders that live on the forest floor are important members of forest food webs. In a study conducted in western North Carolina, the researchers found that salamanders were five times more numerous in mature forest stands than on recent clearcuts. Also, the clearcut areas averaged only about half as many species as did the mature forest sites. One of the most disturbing findings of the study was that 50 to 70 years are required for salamander populations to return to pre-clearcut levels. Keep in mind that landowners using intensive forest management in Maine are cutting on 30 to 50-year rotations.

The authors estimated that approximately 70 to 80 percent of salamanders inhabiting mature stands are lost following clearcutting, and most of those probably die due to physiological stress. Other research has shown that clearcutting disrupts the habitat for salamanders by removing shade, reducing leaf litter, and causing dramatic changes in soil surface moisture and temperature.

Research conducted in Maine and published in April of 1998, demonstrated that there were significantly lower numbers and fewer species of salamanders in recent clearcuts than in uncut woods. The scientists identified species of amphibians that were especially threatened by intensive forest management. These included red-backed salamanders, spotted and blue-spotted salamanders, and also wood frogs.

Understory Plants that are not Trees

Plants that are not trees, but that grow in the understory of forests may play important roles in the forest ecosystem. For example, the trout lily is a widespread forest plant that grows actively in the spring during the period extending from snowmelt until the canopy develops and shades the forest floor. One study found that these small plants incorporate significant amounts of potassium and nitrogen into their tissues during their period of active growth in early spring.

If these plants were not present, those nutrients might be lost by leaching from the forest soil during snowmelt and spring runoff. Later in midsummer, the aboveground portions of the trout lily die back and release those nutrients into the soil from which they can be taken up by trees and other plant life.

One study conducted in the southern Appalachians showed that many herbaceous forest understory plants, similar to the trout lily, recover very slowly or not at all from clearcutting. To our knowledge, a similar study has not been undertaken in Maine or in northern New England. However, the widespread use of intensive harvesting methods, short rotations and plantation forestry almost ensure a similar loss of plant diversity in Maine and northern New England.

Healthy Forests, with a Diversity of Tree Species, Have Beneficial Bird Populations

There are also good reasons to have a diversity of tree species in our forests. For example, research conducted in New Brunswick showed that the presence of greater than 40 percent hardwoods in mixed balsam fir-hardwood stands could substantially reduce losses during spruce budworm outbreaks, possibly because the presence of greater hardwood content increased the abundance of natural enemies of the budworm such as birds.

In spite of such evidence, the paper companies insist on clear-cutting which results in even-aged stands of fir (the preferred food of the budworm), and on spraying herbicides to limit the regrowth of hardwoods.

In a study published in 1989, researchers found that birds exert controls on low-density budworm populations. The largest and most important group of predators was the canopy-feeding wood warblers including the Blackburnian, Cape May, Bay-breasted, Yellow-rumped, Magnolia and Black-throated Green Warblers, as well as the Golden-crowned Kinglet.

Suitable habitat for these species must be maintained, including a significant hardwood component, and well-developed canopy and subcanopy layers. Unfortunately, intensive forest practices destroy these essential habitat features.

The topic of birds leads to a discussion of John Hagan's research on the diversity and abundance of land birds in a northeastern industrial forest, published in 1997. This research, which was supported in part by the forest products industry, has been cited frequently by representatives of the paper industry as evidence that Neotropical songbirds benefit from industrial clearcuts. Actually, a careful reading of this paper shows that such a sweeping conclusion is not warranted.

First, it is important to note that this study was not conducted on typical industrial clearcut areas. The regenerating clearcuts had not been sprayed with herbicides, as is common practice on industrial lands. Therefore, one cannot generalize from Hagan's study that all industrial clearcuts are good for birds.

Second, data on relative abundance of birds, such as that collected for this study, do not necessarily indicate successful breeding and reproduction. In fact, an earlier study published by Hagan in 1996, showed that the sudden loss of habitat on clearcut sites forced breeding birds to disperse into adjoining forest fragments or buffer strips where they attempted to re-establish breeding territories.

Overall songbird densities were observed to increase above normal levels due to the crowding of birds into the forest fragments. Hagan studied one species, the Ovenbird, in more detail, and found that crowding resulted in decreased mating success. Therefore, just because one counts a relatively large number of birds in or near a clearcut area over a short period of time, that does not mean that the birds are reproducing successfully.

Finally, it is important to note that different species of neotropical songbirds have different habitat requirements. Some species do indeed prefer young, regenerating tree growth, and those are the species that Hagan found in greatest abundance in regenerating clearcuts.

However, other species require mature forest habitat, and those species are the ones that are suffering the most from intensive forest practices. In fact, in Hagan's own words as quoted from his research paper, "Over the coming decades, if harvest rates are maintained at current levels, bird (and other) species likely to decline in abundance will be species that prefer mature-forest habitats or large tracts of continuous mature forest coverage."

Furthermore, it is important to know that large clearcut areas are not needed to provide habitat for bird species that utilize young tree or shrub growth. A study in Vermont published in 1997, showed that one-acre patch clearcuts within extensive mature hardwood forest provided habitat for several songbird species which thrive in regenerating or immature woods. These smaller patch cuts more closely mimic natural forest gaps, such as those created by a large old tree dying and falling over.

Other research, conducted in New Brunswick and published in 1994, showed that clearcutting, intensive silviculture, and single-species tree plantations, reduced habitat diversity and decreased the density and diversity of breeding birds.

Other Fauna Adversely Affected by Intensive Clearcutting

Other types of wildlife are also adversely affected by intensive forest practices. Scientists studying bats in the White Mountain National Forest, for example, published a paper in 1996 in which they hypothesized that prior to European settlement, northeastern bats were inhabitants of extensive tracts of over-mature hardwood timber.

Bats probably used large dead and dying trees as roosts, and probably fed in small openings created by natural disturbances or over areas of still water. In order to create bat habitat and maintain viable bat populations within the White Mountain National Forest, timber management plans were recommended which created small forest openings, that is group selection cuts and small clearcuts, and retained areas of older hardwoods. Intensive timber harvesting methods would be inappropriate since they would destroy the essential habitat mixture of over mature hardwood and small openings.

NOTE: Moose are probably Maine's most famous type of wildlife, and they have been thriving by feeding on vegetation found in regenerating clearcut areas, as well as that found on old farm land that has been abandoned. However, research has shown that moose avoid using herbicide-treated clearcuts, and when they are found within treated areas, they are feeding on vegetation that was inadvertently skipped by the spray plane.

Summary

In summary, there is a large body of scientific evidence which shows intensive forest practices, such as whole-tree clearcutting on short rotations, herbicide spraying, and the establishment of tree plantations, have adverse effects on all aspects of the forest ecosystem, and we believe these practices threaten the long term health and productivity of our forestlands. We support the use of forest practices such as those promoted by the Maine Low Impact Forestry Project, and practiced by veteran woodlot owners like Mel Ames of Atkinson.

In 1995, the U.S. Forest Service conducted a survey of the Maine woods, and published the data in late 1996. However, neither Maine nor the U.S. Forest Service had prepared a written analysis of the data when, in February 1998, Mitch Lansky produced his own cogent summary of the survey data.

Finally, approximately 7 months later, the Maine Forest Service, in cooperation with the U.S. Forest Service, produced a report which showed clearly that the woods in Maine (on which harvesting takes place) are being cut faster than they grow, and there will be a shortage of wood if present cutting rates continue. See note.

NOTE: The standard criteria is Net forest growth on harvested areas (= Gross forest growth – mortality) should be at least 25% to 35% greater than the annual harvest to ensure adequate nutrients and sustainable forests.

Unfortunately, the state is advocating the use of more intensive forest practices, including herbicide spraying and tree plantations, to try to make up for the looming shortage of wood fiber.

The people of Maine should not be complacent about the direction the Maine woods is headed. Bernd Heinrich, in his excellent book, The Trees in My Forest, described what has happened in the country of Finland, where, as in Maine, pulp and paper companies dominate.

Ninety-eight percent of Finland's tree growth is now in even-aged monocultures of Scots pine and Norway spruce. Finland now has virtually no real forest! It is time for the people of Maine to oppose this move toward more intensive management while we still have some real forest left.

Forest Ecology Network Activist Profile: LeRoy and Barbara Bandy

LeRoy Bandy has a PhD. in wildlife ecology from Ohio State University. He has conducted research on waterfowl biology and on the movement of DDT in the environment. He has also done environmental survey work, and taught college courses in human ecology, and the ecology and taxonomy of flora and fauna. In recent years he has been conducting surveys of birds found in woodlots which are managed by low-impact harvesting techniques.

Barbara Bandy has an M.S. degree in Botany from the University of Maine. She worked in research labs as a research assistant for 15 years before changing careers to become a registered nurse in cardiac intensive care.

The Bandys have compiled an annotated bibliography of their research. It is posted on FEN's web site. They are available for speaking engagements for classes and organizations. Call FEN at 623-7140 for details.

 

FEN Home Page / Join FEN / Email FEN

283 Water Street, 3rd floor, P.O. Box 2118, Augusta, Maine 04338
Phone: 207-623-7140  
email: fen@powerlink.net

APPENDIX 1

Clearcutting Damages Forest Floors and Causes Decay of Belowground Biomass

Clearcutting destroys the understory flora, damages the forest floor and the belowground biomass. As the belowground biomass is no longer needed it decays. The resulting decay CO2 would be in excess of the CO2 absorbed by biomass regrowth on the clearcut areas for about 15 years. After that, it would take up to 20 years until the biomass regrowth on the clearcut areas would have absorbed the excess CO2 of the first 15 years. The about 35 years is called the C-neutrality period.

Only after the C-neutrality period would any biomass combustion CO2 (emitted during year 1) be absorbed. The new biomass growth would absorb that CO2 only as fast as it needs to, i.e., at a fast rate up to year 40 to 50, and slower rates thereafter. The biomass combustion CO2 of year 2, and of each subsequent year, each have to wait about 35 years, etc.

 

In northern climates, with 4-month growing periods, the whole absorption process would take about 80 to 100 years to completion. At the end of that period one can claim wood burning as having been “renewable” regarding the biomass combustion CO2, i.e., about 115 to 135 years after burning the wood in year 1.

 

Any CO2 of the A to Z process (upstream, plant operation and downstream), other than biomass combustion CO2, should be treated as any other CO2. See URL.

http://www.windtaskforce.org/profiles/blogs/co2-emissions-from-logg...

 

NOTE: Prior to any clearcutting, the clearcut areas were absorbing and storing CO2 at a rate of about 1.0 metric ton per acre per year, for free.

 

The Vermont Biomass Energy Research Center

 

BERC, a pro-logging industry consultant, which is part of the pro-renewable Vermont Energy Investment Corporation, VEIC, invented a unique method of calculated CO2 from wood burning plants that has no parallel anywhere else, and is likely not used anywhere else, except in Vermont. It completely ignores the above 35-year C-neutrally period, and the slow absorption of combustion CO2 over about 80 to 100 years thereafter, and it ignores the year-after-year CO2 build-up in the atmosphere while the CO2 is slowly being absorbed by the regrowth on the harvested areas.

 

The BERC-invented 82% CO2 reduction must give great comfort to wood burning proponents, because BERC purposely forgot to add "over about 80 - 100 years after the C-neutrality period". Here is a quote:

 

“While the recommended carbon emission factor of 29.58 pounds per million Btu is far from the historic “carbon neutral” stance, when compared to the carbon emissions (165.5 pounds per million Btu) from burning heating oil, it represents an 82% reduction in CO2 emissions’.

https://www.biomasscenter.org/pdfs/veic-carbon-emission-and-modern-...

APPENDIX 2

Old Growth Forests Store at Least 2 Times the Carbon of 60-y-old Forests

Old-growth forests store more carbon than younger forests, because they had more time to grow larger trees and develop a complex forest floor. The following chart shows the carbon storage within the components of a young forest and ancient forest ecosystem. Forest floors in old-growth forests contain significantly more carbon than forest floors of harvested forests (Lecomte et al. 2006; Fredeen et al. 2005; Harmon et al. 1990).

https://www.biologicaldiversity.org/programs/climate_law_institute/...

 

Table 1/Carbon storage

60-y-old forest

Old-growth forest

metric ton C

metric ton C

Foliage

5.5

6.2-7.0

Branches

7.0

26.3

Boles (wood and bark)

145

323.0

Roots (fine)

5.6

5.6

Woody debris and forest floor

10.9 - 26.1

123.0

Total

203 - 218

555 -556

 

APPENDIX 3

Carbon Content of Wood: The carbon contents in heartwood of softwood and hardwood species were determined. C in kiln-dried hardwood species ranged from 46.27% to 49.97%, and in conifers from 47.21% to 55.2%. Heartwood is the older harder non-living central wood of trees that is usually darker, denser, less permeable, and more durable than the surrounding sapwood.

https://www.sciencedirect.com/science/article/pii/S0961953403000333

 

The average higher heating value, HHV, of the more resinous softwoods is about 9,000 Btu/lb of dry trunk wood, and for the less resinous hardwoods about 8,300 Btu/lb of dry trunk wood. The EPA selected an average value of 8600 Btu/lb of dry trunk wood.

 

Wood Chips for Burning: Wood chips usually are made from whole trees that are fed into very large chippers. It is a noisy sight to behold. A large crane grabs an 18-inch diameter tree, feeds it horizontally into the big hopper, and within about a minute the entire tree has become wood chips that are blown into a 40 ft trailer!!! The trees are low quality trees, and often are misshapen, sickly and dead trees.

 

Whole tree wood chips consist of about 50% carbon and about 6% hydrogen (by weight) and have a typical heat content of 4785 Btu/lb at 44% moisture content, or 4785 / (1 - 0.44) = 8545 Btu/lb, HHV, dry. See URLs

 

CO2 emissions of wood, per EPA, are (1000000/8600, HHV) x 0.50, C fraction x 44/12, mol. wt. ratio = 213.18 lb/million Btu.

 

CO2 emissions of wood chips, per BERC, are (1000000/8545, HHV) x 0.50, C fraction x 44/12, mol. wt. ratio) = 214.6 lb/million Btu

 

https://phyllis.nl/Browse/Standard/ECN-Phyllis##2718

https://www.biomasscenter.org/images/stories/Woodchip_Heating_Fuel_...

https://ucanr.edu/sites/swet/files/274491.pdf

 

NOTE:

The 44/12-molecular weight ratio is calculated as follows:

The combustion equation is C + O2 --> CO2 

Molecular weight of CO2 = 12 lb C + 32 lb O2 —> 44 lb, or

12/12 ton C + 32/12 ton O2 —> 44/12 ton CO2

https://mha-net.org/docs/v8n2/docs/WDBASICS.pdf

APPENDIX 4

Higher and Lower Heating Values: The HHV is determined with a “bomb” calorimeter in a laboratory. Fuel is fed in, at say 60F, and combusted with pure oxygen until combustion is complete. Heat is extracted from the products of combustion to reduce their temperature to 60F. The water vapor due to combustion of hydrogen in the fuel (2 H2 + O2 --> 2 H2O) is condensed and cooled to 60F. See note and URLs.

 

https://www.ddscalorimeters.com/why-high-pressure-oxygen-is-used-in...

https://en.wikipedia.org/wiki/Calorimeter

 

LHV = HHV – energy from condensed water vapor from hydrogen combustion.

LHV of a fuel should be used when performing calculations to determine the efficiency of a heating plant, as shown Appendix 5.

 

HHV is one of the properties of a fuel, as sold in the marketplace.

 

However, if a fuel is combusted, the temperature of the flue gases of boilers and furnaces is very rarely reduced to condense the water vapor, because that would rapidly corrode the ductwork to the precipitator and steel plates of the precipitator that removes most of the particulates from the flue gases, and the ductwork to the chimney and steel liner of the chimney.

 

The “energy from condensed water vapor from hydrogen combustion” goes up the chimney.

The larger the hydrogen weight percent in the fuel, the greater the water vapor weight percent in the flue gases.

 

NOTE: In case of real-world conditions, the flue gas has water vapor due to:

 

1) Combustion of hydrogen in the fuel

2) Humidity of the combustion air and in excess air

3) Water in the wood chips

 

Items 2 and 3 have nothing to do with the definition of LHV. However, some people subtract all three items from HHV to obtain their LHV.

NOTE: Flue gases often contain acidic gases that condense at higher temperatures than water vapor. Any heat recovery from flue gases, such as for drying wood chips, must maintain the flue gases above the condensing point of any acidic gas, usually about 270F - 300F.

NOTE: Households often have wall-hung, gas or propane fired, condensing furnaces, such as by Viessmann and Buderus (both made in Germany).

 

- During a fall or spring day, the circulating hot water for space heating is heated to about 130F (the furnace is in condensing mode, about 95% efficient).

- During a cold winter day, the circulating water is heated to about 170F (the furnace is not in condensing mode, about 85% efficient).

- If a house is highly sealed and highly insulated and has suitable baseboard radiators, the circulating water would be about 130F, or less, most of the heating season, and the furnace would be in condensing mode most of the season.

 

NOTE:

HHVs and LHVs of Some Other Fuels

- E10, usually called gasoline, also called gasohol, is a blend of 90% gasoline and 10% E100.

- B100 is 100% biodiesel

- B20 is a blend of 80% petroleum-diesel and 20% B100

See table 3 and URL.

 

https://h2tools.org/hyarc/calculator-tools/lower-and-higher-heating...

http://nhcleancities.org/2017/04/can-compare-energy-content-alterna...

https://afdc.energy.gov/fuels/fuel_comparison_chart.pdf ;

Table 2

Ethanol

Gasoline

E10 (90/10)

Petro-diesel, LS

B100

B20 (80/20)

NG

LNG

 

 

 

 

 

 

 

Btu/lb

Btu/lb

HHV, Btu/gal

84530

124340

120359

138490

127960

136384

22453

23735

LHV, Btu/gal

76330

116090

112114

128488

119550

126700

20267

20908

APPENDIX 5

Manufacturer Efficiencies vs Real World Efficiencies: When manufacturers test their wood chip boilers, they use a carefully selected sample of dry wood chips. They determine the heat content, Btu/lb, of the wood chips with a “bomb” calorimeter in a laboratory. They operate their boilers at high output in steady output mode. They continuously monitor:

 

Inlet conditions; fuel input and its temperature, and excess air flow and its temperature.

Outlet conditions; flue gas temperature and CO content; hot water flow, and hot water in and out temperatures.

 

In this manner, they can calculate the high thermal efficiencies stated in brochures.

The efficiencies in the real world are significantly less, as shown in below table.

 

Efficiency of Heating Plant; calculated by the Loss Method

Information extracted from this URL

https://mha-net.org/docs/v8n2/docs/WDBASICS.pdf

 

Heating value of wood

 

H2 + ½ O2 à H2O, plus 62,000 Btu/lb

C + O2 à CO2, plus 14,600 Btu/lb

1 lb wood is 48% C, 0.48 x 14,600 = 7,008 Btu/lb

1 lb wood is 6% H, 0.06 x 62,000 = 3,720 Btu/b

1 lb wood = 10,728 Btu, theoretical

The generally accepted HHV is 8600 Btu/lb, dry

 

1) Heat Loss due to water vapor produced by burning hydrogen

 

2 lb H2 + 16 lb O2 à 18 lb H2O

Carbon in 100 lb of dry wood is 48 lb

Hydrogen in 100 lb of dry wood is 6 lb

0.06 lb H2 + 0.48 lb O2 à 0.54 lb H2O

Heat of vaporization is 1058.2 Btu/lb water

Evaporation loss = 0.54 x 1058.2 = 570 Btu/lb*

LHV = 8600 - 570 = 8030 Btu/lb, dry

 

The maximum possible boiler efficiency could be 8030/8600 = 93.4%, if all other losses were ignored.

The EPA mandates the use of 8600 Btu/lb, dry, for emissions calculations.

The wood chip fuel likely has less than 8600 Btu/lb, dry.

 

* Excludes heating from fuel inlet temperature to chimney outlet temperature.

 

2) Heat Loss due to moisture content in wood

 

Moisture content, mc, dry weight basis

mc dry basis, % = (Weight wet - Weight dry)/Weight dry x 100

mc dry basis, % = (115 w - 100 d)/100 d x 100 = 15%

 

Moisture content, mc, wet weight basis

mc wet basis = (Weight wet - Weight dry)/Weight wet x 100

mc wet basis = (115 w - 100 d)/115 w x 100 = 13%

 

or

Wood, dry = (1 - 0.15) x 100 lb = 85 lb; water is 100 - 85 = 15 lb

Wood, wet = 1/(1 + 0.15) x 100 lb = 87 lb, water is 100 - 87 = 13 lb

 

See equilibrium moisture content graph and table in URL

At 80% humidity, mc is 15%

Assume wood chips are pre-dried with heat recovered from flue gases to 15% mc

Heat available = 0.85 x 8030 = 6826 Btu lb, as fed to boiler

 

NOTE: If 1000 lb of grain is harvested at 25% mc, and dried to 14% mc, what is the final weight of the dried grain?

Final weight of grain = 1000* (100 - 25)/(100 - 14) = 872 lb at 14 % mc

 

3) Heat loss due excess combustion air, assumed at 30%

 

1 lb C requires 11.52 lb of air, or 0.49 lb C requires 5.65 lb of air

1 lb of H2 requires 34.56 lb of air, or 0.06 lb of H2 requires 2.07 lb of air

1 lb of wood requires 5.65 + 2.07 = 7.72 lb of air

Excess air is 0.3 x 7.72 = 2.32 lb

Temp difference = 270F, leaving stack after heat recovery - 70F, fuel feed in = 200F

Air specific heat is 0.24 Btu/lb

Heat loss due to excess air is 2.32 x 0.24 x 200 F = 111 Btu/lb of wood. See note

 

NOTE: If excess air were 100%, loss would be 370 Btu/lb of wood.

 

4) Combustibles in flue gases, 0.25% of 6715 = 34

 

5) Combustibles in bottom ash, 1% of 6715 = 67

 

Embedded and decommissioning/landfill energy are ignored.

 

Table 3/Efficiency %

HHV basis

LHV basis

 Btu/lb, dry

 Btu/lb, dry

Theoretical, but essentially impossible total, see URL

 10,800

 10,800

Generally accepted HHV, per EPA

8600

8600

Process losses

1) Reduced due to water vapor from burning hydrogen, LHV = HHV- 570

8030

8030

2) Reduced due to moisture content - see URL and make your choice; 15%

6826

6826

3) Reduced due to excess air - see URL and make your choice; 111

6715

6715

4) Reduced due to combustibles in flue gases, 0.25% of 6715 = 34

6698

6698

5) Reduced due to combustibles in bottom ash, 1% of 6715 = 67

6631

6631

Equipment deficiency losses

6) Reduced due to air in leakage of boiler and ductwork; 34

6597

6597

7) Reduced due to boiler jacket, 2% of 6715 = 134

6462

6462

8) Reduced due to boiler room piping and equipment, 1% of 6715 = 67

6395

6395

Heat to hot water distribution system

6395

6395

Boiler efficiency, %, steady conditions

74.4

79.6

Plant self-use; electrical energy and vehicle fuel input, 6% of 8600

516

516

Plant energy input 

9116

8546

Plant efficiency, %

70.2

74.8

Distribution system loss due to pumping and heat transfer = 8% of 6395

512

512

Plant + Distr. System energy input

9628

9058

Heating system efficiency, %

66.4

70.6

Wood chip harvesting, chipping, transport = 5% of 8600

430

430

A to Z energy input

10058

9488

A to Z efficiency, %

63.6

67.4

APPENDIX 6

Wood Chip Plants Have 2.2 Times and 3.9 Times the Combustion CO2 of Coal and Gas Plants

 

A 500 MW ultra-super-critical, base-loaded coal plant, at a CF of 0.9, would produce 3,944,700 MWh/y, and require 8,865,227 MWh/y of coal, at 44% efficiency

 

A 500 MW combined-cycle gas turbine, base-loaded gas plant, a CF of 0.9, would produce the same electricity, and require 6,574,500 of gas, at 60% efficiency

 

TWENTY 25 MW, base-loaded wood chip plants, each requiring a FOREST circle of 60-mile in diameter (total area: 20 x 3.14 x 30^2 = 56,520 sq miles!!!), at a CF of 0.9, would produce the same electricity, and require 15,778,800 MWh/y of wood chips at 25% efficiency

 

In the real world, each wood burning power plant would get its wood from an area with a 30-mile radius, or 3.14 x 30^2 = 2,826 sq. mi. As a result, Vermont or New Hampshire could have only a few 25 MW wood burning power plants.

https://www.energycentral.com/c/ec/comparison-wood-chip-and-oil-fir...

 

The wood burning power plant would have 2.2 times the CO2 of the coal plant and 3.9 times the CO2 of the CCGT plant. See table 4.

Toxic Chemicals of Wood Plants Far Exceed Those of Coal Plant: The chemical toxins in the exhaust gases of coal and wood power plants are almost identical in type and quantity per million Btu of fuel input. The wood power plant requires about 51/29 = 1.76 times the Btu input of an equivalent coal power plant, and emits about 1.78 times the toxic pollutants of an equivalent coal power plant. These pollutants are separate from any CO2.

 

Wood burning is far from clean, and dangerous to health, especially during wind-still days frequently occurring in New England during winter, because the unhealthy smoke of chimney's stays near the ground.

 

Table 4/CO2 comparison

Coal

Gas

Wood chips

Ratio

Ultra-super-critical

CCGT

Capacity

MW

500

500

20 x 25 = 500

Efficiency

%

44

60

25

Capacity factor

0.9

0.9

0.9

Hours/y

8766

8766

8766

Btu/MWh

3212000

3212000

3212000

Combustion CO2

lb/million Btu

210.20

117

213

Upstream CO2

%

5

17

5

Lb/metric ton

2204.62

2204.62

2204.62

Electricity

MWh/y

3944700

3944700

3944700

Fuel input

MWh/y

8965227

6574500

15778800

1.76

Fuel input

million Btu/y

28796310

21117294

50681506

1.76

Combustion CO2

metric ton/y

2745591

1120703

4896608

1.78

Upstream CO2

metric ton/y

137280

190519

244830

1.78

Total CO2

metric ton/y

2882870

1311222

5141439

1.78

2.20

1.00

3.92

1.78

APPENDIX 7

The below table summarizes the wood burning power plants in Maine. At 25% plant efficiency, the equivalent energy of 3 out of 4 trees is wasted.

APPENDIX 8

Closing Down Wood Burning Power Plants

 

It would be far better for New Hampshire, Maine and Vermont to shut down wood burning power plants, as time is of the essence regarding “climate change”, according to some people. See table 5 and URL.

 

- In Vermont, utilities are forced to buy wood electricity at about 10 c/kWh, as part of the Vermont Standard Offer program, and as required by the Vermont Renewable Portfolio Standard program.

 

- In New Hampshire a law was passed in 2018 to subsidize money-losing NH wood burning power plants. The plants need to be base-loaded to maximize production and need to sell at about 9 - 10 c/kWh to be viable. The subsidy would impose an extra cost on ratepayers of about $25 million/y. Implementing the law is held up in various court cases for environmental reasons.

 

- The wholesale prices of the NE grid averaged about 5 c/kWh since 2008, courtesy of abundant, domestic, near-zero-subsidized, clean-burning, low-CO2 gas at about 5 c/kWh, and near-zero-subsidized, near-zero-CO2 nuclear at 4.5 - 5 c/kWh.

http://www.windtaskforce.org/profiles/blogs/furnaces-for-heating-an...

 

Table 5/Fuel

 lb CO2/million Btu

 Plant efficiency, %

 lb CO2/MWh

CO2 Ratio

Wood chip; McNeal/Ryegate*

213

25

2907

4.0

Wood chip; Denmark

213

30

2423

3.3

Hard coal

206

41

1712

2.4

No. 2 fuel oil

161

35

1572

2.2

Natural gas, CCGT*

117

55

726

1.0

* Add upstream CO2 (logging, chipping, transport, etc.) of about 5 to 10%, if burning wood chips

* Add upstream CO2 (logging, chipping/pelletizing, transport, etc.) of about 10 to 15%, if burning wood pellets

* CCGT = Combined-cycle, gas turbine plant

APPENDIX 9

Often there is much talk about how efficient new biomass boilers are. Such talk is a clever diversion to confuse/befuddle the lay public.

 

The below comparison shows the likely PM2.5 emissions of the proposed Dartmouth biomass boilers would be equivalent to 351 high-efficiency, wood-fired, household stoves AT ONE POINT. See URL

http://www.windtaskforce.org/profiles/blogs/dartmouth-biomass-boile...

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Comment by Penny Gray on October 26, 2019 at 7:17pm

Excellent post, thank you.  If we don't stop making war on our forests, we'll lose a whole lot more than stumpage.

Comment by Frank J. Heller, MPA on October 26, 2019 at 10:05am

I will eventually calculate the effects on the climate from loss of photosynthesis; may start close to home with Bowdoin college's clear cuts and Mill's widening of Rt. One between bath and Brunswick.

Hannah Pingree on the Maine expedited wind law

Hannah Pingree - Director of Maine's Office of Innovation and the Future

"Once the committee passed the wind energy bill on to the full House and Senate, lawmakers there didn’t even debate it. They passed it unanimously and with no discussion. House Majority Leader Hannah Pingree, a Democrat from North Haven, says legislators probably didn’t know how many turbines would be constructed in Maine."

https://pinetreewatch.org/wind-power-bandwagon-hits-bumps-in-the-road-3/

 

Maine as Third World Country:

CMP Transmission Rate Skyrockets 19.6% Due to Wind Power

 

Click here to read how the Maine ratepayer has been sold down the river by the Angus King cabal.

Maine Center For Public Interest Reporting – Three Part Series: A CRITICAL LOOK AT MAINE’S WIND ACT

******** IF LINKS BELOW DON'T WORK, GOOGLE THEM*********

(excerpts) From Part 1 – On Maine’s Wind Law “Once the committee passed the wind energy bill on to the full House and Senate, lawmakers there didn’t even debate it. They passed it unanimously and with no discussion. House Majority Leader Hannah Pingree, a Democrat from North Haven, says legislators probably didn’t know how many turbines would be constructed in Maine if the law’s goals were met." . – Maine Center for Public Interest Reporting, August 2010 https://www.pinetreewatchdog.org/wind-power-bandwagon-hits-bumps-in-the-road-3/From Part 2 – On Wind and Oil Yet using wind energy doesn’t lower dependence on imported foreign oil. That’s because the majority of imported oil in Maine is used for heating and transportation. And switching our dependence from foreign oil to Maine-produced electricity isn’t likely to happen very soon, says Bartlett. “Right now, people can’t switch to electric cars and heating – if they did, we’d be in trouble.” So was one of the fundamental premises of the task force false, or at least misleading?" https://www.pinetreewatchdog.org/wind-swept-task-force-set-the-rules/From Part 3 – On Wind-Required New Transmission Lines Finally, the building of enormous, high-voltage transmission lines that the regional electricity system operator says are required to move substantial amounts of wind power to markets south of Maine was never even discussed by the task force – an omission that Mills said will come to haunt the state.“If you try to put 2,500 or 3,000 megawatts in northern or eastern Maine – oh, my god, try to build the transmission!” said Mills. “It’s not just the towers, it’s the lines – that’s when I begin to think that the goal is a little farfetched.” https://www.pinetreewatchdog.org/flaws-in-bill-like-skating-with-dull-skates/

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