Biomass, energy and what is available in the Mad River Valley
Editor's Note: This is the second article in a three-part series about wood energy systems in The Valley. The article stems from a collaborative project between UVM, The Valley and others. This article looks at the availability of wood for heating in The Valley.
To look at whether The Valley can produce enough biomass (wood) to sustainably heat the homes of residents, researchers started with the idea that wood energy is an interconnect ecological and social system. They looked at sustainability in terms of five areas:
- evaluating wood availability using Geographic Information
Systems (GIS) and harvest information from tax records and county
foresters to identify actually harvested amounts and theoretically
- surveying forest landowners about their attitudes and decisions
around harvesting wood;
- interviewing loggers to understand their concerns and practices,
and the network of suppliers and forest workers providing the
communities' wood energy;
- surveying local households to better understand the demand for wood fuel and how it is used, as well as sustainability priorities for wood energy and wood energy consumers' choices and values; and
- comparing data to community-wide priorities, plans and values
for future decisions.
Researchers further examined the forested lands that could be suitable for sustainable wood biomass harvest in the study areas using GIS and current public data. Lands unsuitable for harvesting due to steepness, open water or wetlands, limited forest production potential, or roads, buildings, and other non-forest land uses were removed from the calculations. The likely per-acre annual growth of low-quality wood was estimated in green tons using growth rates from several sources. Since it is difficult to accurately estimate biomass production because of wide variability in growth rates and wood quality, a range of values was provided in the final report.
According to this analysis, the Mad River Valley towns' "woodshed," or wood collection area, consists of 50,300 acres, which is 68 percent of the forested lands and 55 percent of the total study area. Nine percent of the suitable land is publicly owned. Several models of growth were used to estimate a range of potential wood harvest. Using a conservative growth rate of 1.2 green tons/acre/year and assuming 38 percent of the wood biomass to be low quality (and thus appropriate for heating or energy production rather than construction or furniture), the Mad River Valley towns' woodshed was estimated to grow approximately 23,000 green tons/year of low-quality wood. This calculation suggests that the MRV towns are growing enough low-grade wood each year to heat up to 94 percent of the permanent population's homes at current rates of use (an average of 3.8 cords per household per year).
According to researchers, locals lands are growing more wood biomass than currently harvested. Analysis of multi-year (2005-2008) harvest data for private lands enrolled in the Use Value Appraisal (UVA) Program (also known as "Current Use") and all public lands within the study areas was conducted to understand volumes and location of wood currently being harvested. No information was available on harvests from non-UVA enrolled private lands. Measuring current harvest numbers was a challenge, due to reasons ranging from lack of reporting incentives for landowners, conversion of wood quantities into consistent units, descriptions of wood types, and even landowner handwriting. The information gathered represents a partial snapshot of the wood harvested by Valley landowners and thus may significantly underestimate the volume of current harvests.
The overwhelming majority of reported harvest volumes over this time period came from private lands, with 94 percent from private UVA enrolled lands, roughly 3 percent each from state and federal lands, and none from town lands.
According to the research, the average annual total harvest from the Washington County towns of Warren, Waitsfield, Fayston and Moretown was 10,190 green tons/year (4,280 cords/year). The average annual harvest of low-grade wood (cordwood and chips) from these towns was 3,838 green tons/year (1,599 cords/year). According to these reported numbers, the towns could potentially heat up to 16 percent of their households with the existing average annual low-grade harvest volumes. (Note: These figures do not consider current competing uses for low-grade wood.) Subtracting the current home and institutional heating demands from the conservative estimate of potentially available low-grade wood leaves at most 64 percent of potential wood growth, or 6,150 cords/year leftover for expanding consumption.
While the two studies noted above supply information and insight into the potential supply and current demand for wood biomass, these efforts to collect baseline information on wood production and consumption suggest that existing data collection or monitoring systems do not provide enough reliable information. The range of estimated growth rates, lack of complete, reliable harvest data at the community level, and invisibility of firewood from measured systems are issues requiring further attention and suggesting caution as pressure for wood consumption continues to increase.
Landowners owning more than 25 acres in the MRV and 5TF were mailed surveys in an effort to better understand their management decisions and motivations related to wood harvesting. Responses were received from 88 MRV forest landowners. About 25 percent of respondents harvested wood in 2008 or 2009. Half of the harvests had no forester involved and two-thirds of the harvests were conducted by family members.
Respondents harvested or removed trees more often to meet forest management goals and to maintain tax status in "current use" (Use Value Appraisal Program) rather than to meet a financial need or goal (Table 1).
Management goals, value of the wood, and tax reductions were the most important factors in deciding to harvest in the future. However 28 percent also indicated that they would be more likely to harvest wood if they had the opportunity to sell or donate to a community-supported firewood program.
Wood supply depends not only on the amount of biomass in the woods but also on the people who harvest, transform and make it available to consumers. Major components to the wood products supply chain in the project area included landowners, stumpage owners, foresters, loggers and haulers, mills, processors, and log brokers, and consumers big and small.
Wood suppliers in the MRV region include three large mills and wood processors. The three sawmills all had land holdings from which they harvested regularly. Although outside the study area, several concentration yards, log brokers, and smaller, regional mills also served the area as important components of the supply chain.
Major wood fuel consumers in the project area include Mt. Abraham Union High School (Bristol), Harwood Union High School, and the kiln operations of A. Johnson Company. Outside the study area, numerous other schools and institutions, including Middlebury College, the Burlington Electric Department McNeil Generating Plant, and the State Office Complex in Waterbury, constitute other major wood fuel consumers in the region.
The paper industry (Ticonderoga Mill in New York) also competes for some of the same wood resources. The remainder of wood fuel demand comes from small and residential scale consumers. A portion of the locally harvested wood enters global and Canadian wood products markets in log and other various processed forms, though this is significantly less true of low-grade (fuel) wood.
Fifteen loggers were interviewed to better understand perspectives on the changing wood market as well as the opportunities and constraints of their operations. The loggers interviewed were a diverse group of small and mid-size operators. Many took jobs in both study areas and elsewhere in the state. Most generally cut the trees, moved them to the landing and participated in the sale of the wood to other parties, sometimes with help from a forester. Some operators harvested under contract to a mill. Few of the small logging operators interviewed had their own capacity to transport logs, making their businesses dependent on truckers and the trucking capacity of concentration yards.
While firewood markets have been readily accessible to producers at almost any scale, the growth of large fuel-grade chip markets, supported by programs such as the Fuels for Schools Initiative, has been out of reach for most small operators. The primary hurdles for loggers to participate in the chip markets were large volume requirements, lack of appropriate equipment (especially chippers and chip transport trucks), very limited purchasing of log length wood for fuel chips, and the need for on-demand delivery due to limited storage capacity at fuel user sites. Wood chip fuel markets tended to favor those few operators who are fully mechanized and capable of large volume production.
Despite the apparent abundance of wood resources in Vermont's forests, the loggers reported difficulty securing enough wood to meet energy demands and cover business overhead costs. They observed that poor timber prices encourage low supplies, since fuel wood is a side product of timber harvests and thus directly affected by high-quality timber markets. Respondents suggested that higher energy prices will be needed to make fuel wood harvests viable on their own.
To better understand residential wood energy use and personal values, household wood consumers were provided surveys through local schools, grocery stores and personal networks. One hundred-ninety-five valid responses were received from the Mad River Valley.
Seventy-two percent of the survey respondents reported acquiring cordwood in the last year. Most households reported acquiring five cords or fewer. The average annual consumption of firewood per household was 3.7 cords in the Mad River Valley, and 2.6 tons of pellets. The number of households purchasing wood was roughly equal to the number harvesting from their own property (Table 2). Of those who acquired firewood but did not harvest their own, 55.6 percent did not know where the wood came from.
Household respondents expressed a strong preference for wood products that could meet sustainable environmental and social requirements (Table 3). About half of the respondents were interested in community-supported firewood opportunities that would ensure sustainably produced wood.
Other major consumers included commercial operations and institutional users. Major institutional consumers of wood for heating include power plants in Burlington (180K tons/year) and Ryegate (250K tons/year). Middlebury College's biomass plant, which started running in 2009, is estimated to use 20K tons annually. At least eight state facilities heat with wood and one hospital uses wood for co-generation of heat and power.
Vermont's wood-heated schools use about 20K tons annually. Harwood Union High School was identified as a school where fuel supply could be reviewed as part of the project. Biomass Energy Resource Center (BERC) has been evaluating the school's existing woody biomass fuel supply and will make recommendations about developing wood fuel procurement strategies.
An additional aspect of the project is to work with the community to develop measures of sustainability to encourage the different people involved in the management, use and procurement of biomass to begin speaking the same language around wood harvest. Forest management and harvest have long been guided by best management practices and forest certification systems are everywhere at this point, but the harvest of wood biomass for use as fuel presents unique challenges and opportunities.
The University of Vermont's Center for Sustainable Agriculture and Rubenstein School of Natural Resources, Vermont Family Forests (VFF) and Northern Forest Alliance (NFA) have partnered in a three-year collaborative research project to explore the sustainability of community-based wood biomass production and use within communities of the Mad River Valley (MRV) and the parts of Addison County. Additional collaborators on the project include individuals from the Biomass Energy Resources Center (BERC), the Forest Guild and Middlebury College.
The final article in this series will highlight the issues revealed through the project and address the question of where we go from here. For more information about the project, including full reports, visit www.mrvenergy.org or www.uvm.edu/forestcarbon/biomass.