Monday, January 21, 2008
The Renewable Energy Act (REA) defines "renewable" as energy generated by solar, wind, hydroelectric, geothermal and biomass [Section 3-D-(2)]. Since the general public, including government officials, equate “renewable” with “clean”, this leaves the false impression that biomass is a clean energy alternative similar to solar and wind.
This belief is reinforced by a provision in the REA that states that “renewable energy means electric energy generated by the use of low- or zero-emissions generation technology” [Section 3- D-(1)]. The problem is there is no quantified standard defining “low emissions”. As a result, the Air Quality Bureau of the Environment Department simply regulates biomass under the same guidelines as a typical coal fired plant. Further, since there is no quantified standard defining low emissions, there is no incentive for the biomass electric producers to use the best available technology.
This major loophole in the REA permits biomass power plants to be a “major source” of pollutants according to NM Air Quality Bureau standards and yet still be considered a low-emission polluter. Indeed, according to conversations with the NM Air Quality Bureau and the NM PRC, under current regulations biomass fuel fired electric generating plants can often pollute on the scale similar to average coal fired plant in the US.
Evidence: EPA's national emission tracking system estimates that an average coal fired plant in the US emits nitrogen oxides, the stuff of industrial pollution and acid rain, at a rate of 2.8 lbs per hour per megawatt of power . A recently proposed biomass plant for Estancia valley in central New Mexico, if built, plans to emit nitrogen oxides at a rate of 1.5 lbs per hour per megawatt . This is a rate over 53% of a typical coal fired plant. The Estancia plant plans to emit over 230 tons per year of nitrogen oxides which are 320 times more potent a greenhouse polluter than CO2 . The plant also plans to emit 220 tons of carbon monoxide and hundreds of tons of other pollutants like sulfur dioxide, volatile organic compounds, hazardous and toxic air pollutants like mercury, ammonia and formaldehyde and a range of small particulates. Indeed, the mercury emission rate of the proposed Estancia biomass plant  is estimated to be more than 15 times that of the San Juan generating station . This is certainly not low emissions and defies to spirit of clean renewable energy.
This problem is not unique to New Mexico. The meaningless "zero to low emission" qualification can also be found in other state renewable energy acts.
Without a numeric standard, biomass electric producers have no incentive to install more costly pollution controls. The proposed Estancia plant appears to be designed to be just under the 250 tons per year threshold where stricter pollution controls would be required according to the NM Air Quality Bureau. In effect biomass producers are allowed to produce the highest rate of pollution at the least cost. And you can blame them because they want to minimize costs and maximize profits.
This is a regulatory issue. True low emission technologies are available that would greatly reduce emissions from biomass generating plants. The “low-emission” qualification in the REA simply needs to be quantified if it is to have any meaning.
In short, biomass should either be taken out of the Renewable Energy Act because it is a major source of air pollution or a low emission standard should be quantified requiring biomass electric producers to actually abide by a low-emission standard. In this way the spirit of a clean renewable energy program will remain intact in New Mexico and not subject to abuse, deception and public misperception.
 Western Water and Power Production, LLC, Estancia Basin Biomass Facility, Permit Application, 20.2.72 NMAC, Air Quality Bureau, Santa Fe, NM
Sunday, January 20, 2008
The total biomass available within a 50-mile radius of the plant using all readily available woods and using good forest harvesting principles would supply the biomass plant for no more than 5 years without doing irreparable harm to the forest ecosystems.
WWP has applied for renewable energy production tax credits made available through New Mexico’s Renewable Energy Act (REA) and under the state’s rule for administration of the REA production tax credit (NMSA 1978, Section 7-2-A-19 as amended in 2007 by SB 463 and 3.13.19 NMAC.) The REA was passed to promote energy self-sufficiency, preserve the state’s natural resources and pursue an improved environment in New Mexico.
New Mexico Energy, Minerals and natural Resources Department (EMNRD) is in the process of reviewing an appeal by Western Water and Power Production Limited, LLC (WWP) of the Energy Conservation and Management Division’s denial of WWP’s request for tax credits under New Mexico’s Renewable Energy Act (REA) and the state’s rule for administering the production tax credits.
The REA defined renewable energy as “electrical energy generated by means of a low or zero emissions generation technology with substantial long-term production potential and generated by use of renewable energy resources that may include solar, wind, hydropower, geothermal, fuel cells that are not fossil fueled and biomass resources; biomass resources are fuels, such as agriculture or animal waste, small-diameter timber, salt cedar and other phreatophyte or woody vegetation removed from river basins or watersheds in New Mexico, landfill gas and anaerobically digested waste biomass; renewable energy does not include fossil fuel or nuclear energy.”
As a group of concerned citizens we offer the following information which clearly shows that WWP cannot prove the “long term production potential” of biomass on the scale required for a 35 MW power plant and that harvesting biomass on the scale required to operate the plant is not sustainable and thereby violates the REA definition of renewability. Beyond the issue of renewability, our analyses also show that providing 20 years worth of biomass is not even achievable.
This report shows there are no conditions under which the forests within a 50-mile radius are capable of supplying 20 years of biomass to WWP’s proposed biomass plant. It shows that after considering the real amount of available biomass and adherence to good forest harvesting principles, the Estancia biomass plant can only operate for 3 to 5 years beyond which it will exceed renewability and result in environmental damage. In short, this result shows there is no “long term production potential” for biomass at the level of consumption required by WWP for the Estancia biomass plant.
WWP states that about 21.6 million tons of dry biomass is available within a 50 mile radius of the plant. WWP states that 21.6 million tons is more biomass that the plant needs for 20 years of operation thereby implying that all of this biomass is available for extraction.
This report considers the constraints that limit the amount of biomass actually available for power plant consumption within a 50-mile radius of WWP’s proposed biomass power plant near Estancia, New Mexico in developing three separate estimates of available biomass.
• The first estimate imposes the constraint of renewability associated with the New Mexico’s Renewable Energy Act (REA). This analysis starts with the 21.5 million tons of dry biomass estimated in PNM’s Biomass Resource Assessment performed by the Native Communities Development Corporation. Because the REA requires a renewable source of energy this analysis estimates the total amount of dry biomass being generated by the forests within a 50-mile radius of the plant was estimated. If the biomass plant could operate on the amount of renewable biomass within a 50 mile radius it could continue operations indefinitely – consistent with the intent of the REA to transition away from non-renewable energy fossil fuels.
The next two analyses estimate the amount of biomass that can be removed form the forests that are within a 50 mile radius of the biomass plant - assuming that thinning would take place without any regard to renewability or sustainability. Once this wood is removed, the power plant would be completely out of fuel and would go out of operation. This is similar to the PNM estimate except constraints imposed by land ownership, land availability, USFS recommended thinning practices, etc. are incorporated. These two analyses are identical with the following exception:
• The second analysis starts with an independent estimate of the amount of the total amount of dry biomass within a 50-mile radius of the plant.
Both of these analyses then proceed to subtract out lands and biomass that are not available for extraction.
The REA is designed to help move New Mexico from the use of unsustainable fossil fuels to sources of energy that can be relied on in perpetuity. The REA specifically calls for the use of “renewable energy.” WWP proposes to use piñon, juniper, and ponderosa pine derived from clear-cutting and thinning New Mexico forests. The use of forest biomass as an energy source within the REA therefore must be sustainable. In addition, the REA was passed ‘to preserve the state’s natural resources’ and mandated the use of only small-diameter trees and brush. WWP is on record (multiple documented statements at the air quality permit hearings and in published newspaper articles) that the proposed biomass plant would rely only on small diameter timber and brush. In support of its application for tax credits WWP is relying on PNM’s Biomass Resource Assessment(1).
PNM estimates that 21,585,642 tons of dry biomass is physically available within a 50-mile radius of the plant. We know the biomass plant will consume 481,800 tons of biomass per year at the 55 tons per hour, the rate indicated in the air quality permit. In a worst case scenario, clear cutting all land within a 50-mile radius of the plant including all of the Sandia, Manzano, and Gallinas Mountains as well as all the highland piñon-juniper would provide enough wood for the plant to operate for just under 45 years (21,585,642 divided by 481,800 = 44.8yrs). But a renewable energy source should never run out of energy. For example, other renewable energy sources identified in the REA, solar and wind, never run out of energy.
The fact that the biomass plant would clear cut every tree within 50 miles and still completely run out of its production potential in less than 45 years should immediately raise flags about forest thinning as a source of “renewable” energy. For comparison, the proposed Desert Rock coal-fired power plant generating 1,500 MW is scheduled to run for 50 years. At 35 MW (the same as the biomass plant), the Desert Rock plant could run for over 2,000 years. In other words, a fossil fuel plant will last much longer than the proposed biomass plant. Clearly something if fundamentally wrong with the idea of New Mexico forests as a source of renewable energy.
But trees grow, so aren’t they a source of renewable energy like wind and solar? To be a source of renewable energy trees must grow at the same rate as the energy demand or 55 tons per hour over the 50-mile radius. Solar and wind, true sources of renewable energy, by definition supply energy at the rate it is used – forever. WWP has stated that the principle source of biomass extraction will be piñon-juniper forests. These forests grow at rate of 1% per year(2). Assuming every acre of land PNM used in its calculation is available for biomass extraction and assuming that the PNM figure of 21,585,642 tons is correct, an annual growth yield of 215,856 (1% of 21,585,642) tons per year is the actual renewable rate. This is less than half of the 481,800 tons per year required to fuel the biomass plant.
What this means is that if we started by clear cutting, then every new tree would have to be cut every year. If we started by thinning, it would mean that every inch of new growth would need to be removed from the forest – existing trees stay the same size, no wood for traditional wood cutters, no biomass for continued soil formation, no wood available for anything other than this biomass plant and still only provide ½ of the fuel requirements of this plant to run at full capacity.
Note that the USFS recommends 200-year-rotation management for harvesting juniper(3). In other words, the USFS recommends waiting 200 years after harvesting trees until any more are cut. The federal and state land agencies do not recommend clear cutting. In recent proposals for the federal lands in the Manzano Mountains, the USFS recommended 45-75% removal(4) and when thinning, leaving 5-7 tons per acre of biomass on the ground for erosion control and soil regeneration. Following just these recommendations would further restrict the ability of the biomass plant to produce energy in a sustainable manner.
In summary, the REA requires the use of a renewable source of energy and the proposed source of wood for WWP’s proposed biomass plant is clearly not renewable.
The following analysis is based on the possibility that the New Mexico Energy, Minerals, and Natural Resources Department will ignore both the spirit and the letter of the REA in their decision on tax credits for WWP. That is, they will not require WWP to prove the supply of wood is either renewable or sustainable.
The starting point for this analysis is also PNM’s estimate of available biomass. If we ignore the spirit and intent of the REA of providing New Mexicans with a renewable source of energy, the question of biomass supply is: can enough biomass be extracted from available lands to fuel the biomass plant for the 20 year life of the project? At 21 years all the available wood is gone, the plant is out of operation, and the state tax payer’s investment in renewable energy to replace fossil fuels has failed. But let us continue anyway.
PNM’s biomass resource assessment (included in the WWP application for production tax credits) is an analysis of all of the woody biomass that is physically on the landscape. In concluding that there are 21 million tons of woody biomass available, PNM’s assessment states that sufficient biomass would only be available if the following conditions are met:
• “thinning yields must be maximized”
• “thinning is conducted on forests owned by multiple entities”
In fact to procure all of this wood, WWP would have to clear cut every acre on all of the land within the 50-mile radius. There are a number of reasons why WWP cannot access all of this wood including:
1. The trees do not actually exist. This category is referring to lands that still show up on GIS coverages as vegetated including:
• Areas already thinned
Both federal and private lands thinning using state money has occurred over the past 20 years or so. These lands still show up in GIS vegetation coverages as vegetated. Limited databases are available that describe the actual vegetation state of these lands.
• Burned areas.
Wildfires and prescribed burns that escaped the bounds of their prescription are included in this category. The Lookout fire in the Gallinas Mountains alone covered 5,200 acres. Note prescribed burns that stayed within their prescription are not included in this category because these burns characteristically are set within previously thinned forests. The USFS has a GIS coverage that includes locations and areas of fires that have occurred in this region.
2. Thinning is not allowed on some lands.
• Private lands that have covenants prohibiting thinning at all and/or commercial thinning. With very little effort we have obtained legal descriptions of several large developments that exclude thinning. Certainly there are many others.
• State Parks
• Archeological Sites. According to the state archeologist the average number of sites is one per every 50 acres in New Mexico. In this region, especially south of the power plant the number is much greater. A fifty foot buffer is required around each site.
• Wilderness areas
• Protected areas within forests such as riparian areas, along roads, camp grounds, etc.
3. Forest thinning principals need to be adhered to on state and federal lands.
• the intent and initial requirement of the REA was that only small-diameter timber be cut. WWP has endorsed this requirement repeatedly at the air quality permit hearings and in the local newspaper. The USFS and the University of Washington have published quantitative assessments of available biomass as a function of tree diameter(4). This study provides canopy coverage, available tons, and associated photographs(4) The breakdown of diameters in this database is less than 2 inches, 2 to 9 inches and greater than 9 inches. Being very generous anything less than 9 inches could be considered ‘small-diameter timber.’ Research presented in this study provides a breakdown of the tons of biomass available in each class size. We use the ratio of the tons of biomass less than 9 inches to the tons of biomass greater than 9 inches to scale the estimates of wood available within the 50-mile radius of the plant. The ratio of small-diameter (less than 9 inches) to the total biomass for all P-J studied sites is 40%.
• slope constraints. PNM uses 30% - we agree.
• the need to leave some trees. PNM/WWP’s analysis assumes that no trees will be left behind. Forest service requirements for the Thunderbird Project5 – a P-J and ponderosa pine logging project just west of the proposed biomass plant, called for removal of 45 – 75% of the trees in an area they chose because of its current very overcrowded conditions (their words).
4. Federal and state land cannot be guaranteed and many private lands will be inaccessible.
• Federal lands
Not all federal land will be available for the practical reason that the federal government has an increasingly limited budget. A review of the history of thinning in the Manzano Mountains shows several major thinning projects including upper Tajique Canyon, Red Canyon, and the Thunderbird project. However, these projects have occurred over a period of more than 30 years. Therefore the average number of acres thinned per year is very small.
Federal lands cannot be counted on as a source of wood at all because all thinning on federal lands requires the statutory National Environmental Policy Act (NEPA) process. Following NEPA requires: 1) an analysis and fair comparison of a reasonable range of alternatives to the no action alternative (no thinning); and 2) public input to the decision process. According to the Mountainair District Ranger at the Estancia biomass hearing, the USFS would be in violation of NEPA if they guaranteed wood off of any future thinning project to the biomass facility. Since all federal lands (BLM, USFS, DOD, USFWS, etc.) must follow NEPA, no federal lands can be included in WWP’s assessment of available fuels.
• State lands
WWP was successful in securing a sole-source contract for 44,000 acres of state lands south of the power plant. Since that time: 1) the state forestry division has promulgated rules that make piñon-juniper a commercial species thereby invoking stringent rules for the sale and management of these forests; and 2) the public has become aware of what is happening and will be monitoring the thinning of these lands closely to assure natural resources and cultural sites are provided the utmost protection, will insure that other entities are allowed to bid on these lands, and will insure that the taxpayers receive maximum value for their land. Therefore WWP cannot be guaranteed access to all remaining state lands free of competition and environmental regulation as their analysis assumes.
• Private lands
While some large ranches may be available to the biomass plant others have already been thinned. In addition, there is little or no chance of WWP getting any wood off of private land within commuting distance of Albuquerque. These lands: 1) often have covenants; 2) have houses, barns, driveways – not trees; and 3) would present logistical hurdles (number of small trucks, number of contracts, interaction with each landowner daily, etc.) in terms of the large-scale cutting that would be needed to supply the biomass plant.
Using only a few of the above constraints, let’s walk through how much biomass might actually be available. The following table starts with PNM’s estimate of the maximum amount of biomass available within a 50-mile radius of the plant and removes large-diameter trees and provides estimates for the range of thinning rates provided by the USFS.
Complying with the Renewable Energy Act’s mandate that only small-diameter trees be cut yields a plant lifetime less than the 20 years required. Then, even with the maximum thinning (75%) recommended by the USFS, the plant lifetime decreases to 13.4 years and then to 8.1 years if less, but still recommended, thinning is allowed.
Next consider the fact that some lands in the above table are not available and will never be available. Department of Defense (DOD), US Fish and Wildlife (USFWS), and National Park Service (NPS) lands are not available for thinning. In addition, neither federal nor Indian land is a source of guaranteed woody biomass. The following table provides estimates of biomass accounting for land that is unavailable or which cannot be guaranteed.
Roads have no trees and the USFS recommends a 50 foot buffer along drainages(5). We used GIS coverages to estimate the percentage of land covered by roads and streams of about 5%. Subtracting these lands yield plant lifetimes of 10 years and 6 years for the 75% and 45% thinning rates.
Next, about 1/3 of the private land is impractical for harvest by the biomass plant (the highly-developed northern and north-central areas). Taking out 1/3 of the private land yields plant lifetimes of 7.5 and 4.5 years respectively for 75% and 45% thinning rates.
Not quantified but still considered is the fact that the state of New Mexico has been paying private landowners to thin their land through the local Soil and Water Districts. These lands still show up as forested on GIS coverages.
In summary, even if we ignore the letter and the spirit of the REA and assume that PNM’s biomass estimates are correct, there is not nearly enough wood to supply the proposed biomass plant for 20 years.
The next assessment differs from the previous assessment in one major way. The following assessment uses independent data for estimating the tons of biomass available within a 50-mile radius of the plant – the starting point of the analyses.
In the previous analyses we assumed that PNM’s estimate of the amount of total biomass available within a 50 mile radius of the plant is correct. Unfortunately we could not confirm PNM’s estimates because the core data and analysis processes and associated spreadsheets are considered proprietary and not available to the public. Therefore, we researched and found data on the amount of biomass per acre for forests similar to those within a 50 mile radius of the proposed location of the biomass plant. Using a number of sources for GIS coverages, we then estimated the total amount of biomass within a 50-mile radius of the plant. Lands and biomass that are not available are then subtracted from this starting value.
The following figure shows the total forested area within a 50-mile radius of the proposed biomass plant. Following this figure is a table summarizing the tons per acre derived from the PNM estimate. The range in tons of dry wood per acre (tpa) is 3 to 32 with an average of 20 tons per acre of wet wood. As just stated we do not have access to the details of the PNM study. A detailed study by the USFS and the University of Washington(4) of piñon-juniper forests (which represent most of the forests within the 50-mile radius and are the main basis for WWP’s air quality permit) reveals that the tons of wet wood per acre for piñon-juniper forests ranges from less than 2 to 42 tons per acre and the average is 14.5 tons of wet wood per acre or 10.9 tons of dry wood per acre. For comparison, a recent USFS Nevada study indicates that there is only an average of 7.8 dry tons per acre of piñon-juniper biomass statewide(6).
Starting with the independent estimate in the above table the analysis is identical to the previous analysis that started with the PNM estimate of total tons of dry biomass within a 50-mile radius of the plant. Following are maps of biomass and landownership used in this estimate.
In summary, the total biomass available within a 50-mile radius of the plant using all readily available woods and good forest harvesting principles would supply the biomass plant for 3.2 to 5.3 years.
Tuesday, January 15, 2008
This document responds to Brent Racher's affidavit and response to the “Fuel-Wood Estimate for the Proposed WWP Biomass Plant near Estancia, New Mexico” developed by Paul Davis, Bud Latven, and Bill Fogleman and submitted to the NM Energy Secretary dated October 25, 2007.
A biomass plant near Estancia, NM is being proposed solely because of the New Mexico Renewable Energy Act (REA). The REA was passed to encourage the development of clean, renewable energy. With its allowance of higher rates for consumers and tax credits funded by consumers, the act seeks to move New Mexico toward permanent, clean energy sources. Spent wisely, an investment of our tax dollars at this time could provide continuous energy supplies for all time.
Energy sources such as solar and wind are clearly renewable. The sun will continue to shine and fortunately or unfortunately the wind will continue to blow in New Mexico. However, the use of biomass requires an analysis to determine if the rate of energy generation (in this case, tree growth) will meet the energy demand for all time. In addition, proof must be provided to demonstrate that biomass is available to the biomass owners. Available means contractually available, legally available, and available without harm to the environment.
In this light, two estimates of available biomass for the proposed Estancia plant have been developed. One was produced by the Native Community Development Corporation in July of 2005 under contract to the Public Service Company of New Mexico that estimated the total available fuel within a 50 mile radius without regard to renewability and with little regard for availability. Specifically, the issue of renewability (is the rate of energy generation (growth) equal to or greater than the rate of energy use) was not addressed at all. With regard to availability a very limited number of constraints were employed. Essentially this was an estimate of how much wood could be clear cut within a 50 mile radius of the proposed plant.
WWP has been touting this estimate for several years now saying it proves that three times the amount of wood the plant needs is available. However, they have never demonstrated that they have access to this wood or that clear cutting of all forests would be allowed.
A group of concerns citizens then took it upon themselves to evaluate the original PNM estimate. Because PNM would not provide all of the technical details of their estimate to these citizens or to the public at large, this group of citizens produced their own estimate independent of the PNM estimate.
Next comes Mr. Racher, WWP’s thinning contractor, with a criticism of our analysis. Unfortunately, Mr. Racher’s focus on criticizing our work did nothing to reduce the uncertainty about how much wood is renewable and available. That is, the shortcomings of the original PNM estimate were not addressed in Mr. Racher’s criticism of our work.
The fact that Mr. Racher did not clarify the hidden parts of the PNM estimate and the fact that Mr. Racher’s criticisms of our work did nothing the elucidate the amount of renewable and available biomass raises our first and perhaps the most serious concern. Three groups now (PNM, our work, and Mr. Racher’s criticism) have come up with different estimates of the amount of renewable and available biomas. Therefore there is an obvious need for the Energy Department to perform their own analysis. We support and encourage such an analysis with the requirement that any such analysis must address the key issues of renewability and availability.
Our second general response to the criticisms of WWP’s thinning contractor is that WWP has still not proven they have access to sufficient sustainable wood to fire the biomass plant for 20 or 30 years (or whatever their current number is). Mr. Racher attempts and fails to argue that the growth rate is sufficient to renewably provide fuel to the biomass plant and in doing so also fails to address whether or not such fuel is available to the owners of the biomass plant. When all is said and done we are left in the same position, WWP has not proven access to a renewable fuel source for their proposed plant.
The following is a response to specific criticisms raised by WWP’s thinning contractor.
Response to Specific Criticisms
1. ‘Bone dry’ versus ‘green’ tons.
WWP’s thinning contractor argues that we used the weight of green wood that the plant would consume, 55 tons per hour, and should have used the equivalent weight of dry wood, about 30.25 tons per hours. Such a difference would change our estimate of the lifetime of the plant from 3.2 to 5.3 years. If this is indeed a mistake, our calculation for the lifetime supply of renewable and available wood for the biomass plant would change to 5.8 to 9.6 years still far short of renewable and far short of the amount of wood needed to supply the biomass plant for its first 20 years of operation.
While this may seem like a simple straight forward mistake, it is not. Recognize first that the trees being proposed for use in the biomass plant are alive today and green. Therefore some conversion from green, wet wood weight to bone dry weight is required. In addition, wood is never ‘bone dry.’ We understand that wood will be allowed to dry out at the biomass plant prior to burning and will achieve an equilibrium moisture content which is related to the moisture content of the air but this wood will not be bone dry.
The original PNM estimate uses the term ‘bone dry’ but has refused to provide us with the data used in converting green wood weight to bone dry wood weight.
In addition, the basic concept of ‘bone dry’ is not defined. Sounds simple, but it isn’t. In the attachment entitled “Physical Properties and Moisture Relations of Wood.” Moisture content is defined as the ratio of the weight of water contained in the wood to the weight of oven dry wood. Since the density of water is greater than the density of wood, the article points out that, depending on the specific gravity of wood, the maximum moisture content can range from 267% to 40%. Most important, the moisture content does not vary from 0% (‘bone dry’) to 100% as most would expect and as the attached reference points out.
Conceptually, the moisture content at which only the cell walls are completely saturated (all bound water) and where no water exists in cell lumens is called the fiber saturation point. While a useful concept, the term fiber saturation point is not very precise. In concept, it distinguishes between the two ways water is held in wood. In fact, it is possible for all cell lumens to be empty and have partially dried cell walls in one part of a piece of wood, while in another part of the same piece, cell walls may be saturated and lumens partially or completely filled with water. It is even probable that a cell wall will begin to dry before all the water has left the lumen of that same cell. The fiber saturation point of wood averages about 30% moisture content, but in individual species and individual pieces of wood it can vary by several percentage points from that value. The fiber saturation point also is often considered as that moisture content below which the physical and mechanical properties of wood begin to change as a function of moisture content. During drying, the outer parts of a board can be less than fiber saturation while the inner parts are still greater than fiber saturation.
So what does all this mean? It means there is no simple concept of ‘bone dry.’ Bone dry could mean oven dried, it could mean no unbound water, or it could mean a fiber saturation of 30% or even 45%. Yes, bone dry could mean 45% moisture content. But this is not an unsolvable problem. If PNM would simply provide the public with the details of their analysis we would all know the meaning of ‘bone dry.’
Using the definition of moisture content above, it turns out that Mr. Racher calculation is wrong. Mr. Racher assumes that since the wood to be burned has a 45% moisture content he can multiply the total wood demand of 481,800 tons of wet wood by 0.55 and obtain the estimate of 24,990 tons of equivalent dry wood. Using the above definition the correct calculation is:
Weight of water/weight of wood = 0.45
Weight of water = 481,800 – weight of wood
By substitution of the second equation into the first, the weight of wood is:
Weight of wood = 481,800/ (1.45) = 332,275 tons of equivalent dry wood
Now do we have other evidence of what ‘bone dry’ could mean? Possibly.
· In WWP’s draft “Project Design Basis Summary” of March, 2007 the burn rate is given as 75 tons/hr. If we assume this is a ‘wet’ weight and then use the conversion of ‘wet’ to ‘dry’ wood weight from the data obtained from the Sandia Ranger District (see our original fuel estimate for reference), this would yield a dry weight of 56 tons/hr which is very close to the 45% moisture value of 55 tons/hr in the air quality permit. So perhaps, WWP has already done the conversion to equivalent dry weight. In which case our original analysis stands as is.
· As pointed out in our original fuel analysis, the (PNM’s) range in tons of dry wood per acre (tpa) is 3 to 32 with an average of 20 tons per acre of wet wood. A detailed study by the USFS and the University of Washington of piñon-juniper forests (which represent most of the forests within the 50-mile radius and are the main basis for WWP’s air quality permit) reveals that the tons of wet wood per acre for piñon-juniper forests ranges from less than 2 to 42 tons per acre and the average is 14.5 tons of wet wood per acre or 10.9 tons of dry wood per acre. For comparison, a recent USFS Nevada study indicates that there is only an average of 7.8 dry tons per acre of piñon-juniper biomass statewide.
Note that other studies indicate that PNM’s estimate is not an estimate of ‘bone dry’ fuel but is much more consistent with other estimates of wet wood tons per acre.
Bottom line, we have no independent way to evaluate the PNM calculations since they will not share them with us and we have plenty of evidence that our original calculations are correct.
2. Our use of ‘Rocky Mountain Juniper’ instead of one-seed juniper, pinon pine, and alligator bark juniper.
Contrary to WWP’s thinning contractors assertion that we used these data to ‘skew the output’ we used the data because it was available and the PNM data are not available to us. But beyond that Mr. Racher's assertion is incorrect and misleading. First the USFS data set we relied on did include pinon pine and some one seed juniper (see http://depts.washington.edu/nwfire/dps/ Site PJ 14 for example). However, there are no alligator bark junipers in the study and few one-seed junipers. Therefore, we appreciate Mr. Racher pointing out that we systematically overestimated the amount of biomass because the Rocky Mountain juniper is a bigger tree than either the one-seed juniper or the alligator bark juniper (see: http://www.ars-grin.gov/cgi-bin/npgs/acc/display.pl?1727184, http://plants.usda.gov/java/charProfile?symbol=JUSC2)
3. Prescriptions for Thinning.
Our report was based on the premise that some type of thinning prescription would be followed on state, federal, and private lands. So the question was, what prescription should we use? First we found the most recent and nearest thinning project to the proposed location of the biomass plant. That prescription came from the USFS Thunderbird project, a project that included pinon, juniper, and ponderosa pine. That prescription called for thinning 45 to 75% of the material. Mr. Racher is correct that in also applying a diameter cap we may have double counted. However, Mr. Racher failed to recognize that, as we stated, the USFS also mandated leaving 5-7 tons of biomass on the ground for soil development and stabilization. In our analysis we did not subtract this biomass from our available fuel calculation.
Next Mr. Racher questions our use of a diameter cap. Not only do we think a diameter cap is advisable we also believe that it is consistent with the original language of the REA and the stated position of WWP. Throughout the entire public process of permitting of this biomass plant, WWP has claimed they would only cut “small diameter trees”. For example, Mr. Maddox spent considerable time explaining (at the March 2007 air quality permit hearing) that one study in New Mexico shows “215 million trees less than five inches in diameter.” Over and over we have been told the biomass plant will solve the problem of juniper encroachment. For example, the WWP web site (nmbiomass.com) states that ‘Along with juniper, such trees are expanding at a rate of 10 thousand acres per year, which is not sustainable or healthy.’ They fail to mention that if this is indeed the fuel for the plant, these trees are all very small in diameter (from 1 inch to a few inches). In fact, if the goal of this plant was to address juniper encroachment, an age based thinning prescription could be developed since we know the timing of the start of juniper encroachment. Any age based thinning prescription would severely limit the available biomass. As the NRCS points out, mature juniper trees are typically 5 inches in diameter and 150 years old (ftp://ftp-fc.sc.egov.usda.gov/GLTI/technical/publications/Pinyon.pdf) But land treatment is not the reason for this biomass plant. It only exists for one reason – the Renewable Energy Act.
As PNM’s own analysis concludes in its executive summary:
Sufficient biomass would only be available if the following conditions are met:
- thinning yields must be maximized
- thinning is conducted on forests owned by multiple entities
In other words, they know they have to take it all.