By Bruce Beaver, Chemistry Professor, Fossil Energy Expert & Practical Environmentalist
The last several decades have seen massive destructive wildfires in regions as diverse as Alaska, Alberta, California, Colorado and most recently in Tennessee. These fires negatively impact the economy, carbon emissions, forest and human health. Mounting evidence suggests that fire ecology has always been the norm for many forest regions. The media has tended to simplistically attribute these fires to climate change rather than historic land use changes . U.S. Forest Service (USFS) wildfire policy over the last century has also inadvertently contributed to worsening these fires; in addition, recent warming makes the fire season longer. Whether recent warming is greater than historic warming cycles is an area of current active debate.
To address wildfire, existing USFS policies could be rapidly expanded to promote rural economic development while simultaneously enhancing forest and human health. A program to thin one million acres in the dry ponderosa pine forests in Arizona over 20 years was started in 2013. The Four Forests Restoration Initiative (FFRI) is thinning trees to stimulate the health and vigor of the remaining trees and seedlings, increasing their CO2 utilization, and decrease forest biomass making future fires less severe. Such a silvicultural prescription is similar to the natural fire ecological regime of this region. Forest Service subsidies enable small diameter trees to be converted into small dimension lumber to help economically. However, approximately 40% of the harvested biomass was not appropriate for lumber so a biodiesel facility was planned to utilize the biomass. However, financing for this facility was never obtained due to the poor economics of biomass to liquid fuel technology. This situation limits the FFRI economics, and similar plans in other western locations, because the residual biomass has no market. Consequently, this biomass is pile burned on site, which wastes much energy and generates significant air pollution.
The FFRI is part of a larger national USFS initiative called the Collaborative Forest Landscape Restoration (CFLR), which according to the five-year progress report has been hindered by the lack of biomass markets:
“By utilizing woody byproducts from restoration treatments, CFLR projects can help offset treatment costs and generate economic benefits for the community. To date, the 23 projects have generated more than 2.1 million green tons of woody biomass from hazardous fuel reduction and restoration treatments on Federal land made available for bioenergy production. Because of a number of factors external to CFLR, however, including low natural gas prices and the unanticipated impacts of the 2008 economic downturn on the timber market, many of the cogeneration and milling facilities that were planned in project areas are on hold or have shut down. … Even so, without a significant change in demand for biomass and associated development of processing infrastructure, it will be challenging for the projects to meet the proposed lifetime goals for biomass utilization.”
For reference the energy content of 2 million green tons of biomass, produced over 5 years, is about enough to power 24,000 homes per year, if fired in a commercial power plant (1MW/1yr x 1yr/13,000 green tons x 800 homes/1MW x 400,000 green tons/yr = 24,000 homes/yr). Obviously, commercial power plants are already connected to the grid to deliver this power to the homes. However, harvesting, processing and transporting biomass for energy generation is expensive and the economics of the process requires short haul distances (i.e. ~100 mile round trip). This is where the Obama Clean Power Plan becomes important. Since there are over 500 coal-fired power plants dispersed throughout the U.S. it is likely that some power plants are near to forests in need of restoration (thinning). Millions of tons of green biomass are available if forest fuel reduction and landscape restoration projects are started in appropriate regions. Existing commercial coal-fired power plants in these regions, should not be viewed as a source of air pollution to be regulated out of existence, but rather as highly valuable infrastructure for rural economic stimulation. Some of these plants have been or will soon be closed due to the Obama Clean Power Plan. If Mr. Trump stops the Clean Power Plan some of the existing power plants could be rapidly reconfigured to co-fire biomass and provide a market to facilitate USFS thinning polices. The location of the power plants relative to national forests in need of thinning is most important. Implementation of this energy policy would rapidly increase domestic coal consumption since only a maximum of 20% of the co-fired fuel can be biomass in coal power plants. This idea is not far fetched.
In a timely paper Beagle and Belmont report a limited techno-economic assessment of biomass co-firing in existing coal-fired power plants in the Western United States. This limited study examined the potential of co-firing 5 existing coal power plants in Wyoming and Colorado with beetle-killed trees from neighboring national forests. It was found this strategy was both technically possible and economic if currently existing USFS incentives are used to remediate insect damaged forests by biomass co-firing. When coupled with the increase in local employment from biomass harvesting, transportation and processing, this scenario holds great potential for simultaneously enhancing regional air quality, forest health and other local rural social benefits.
A Trump policy to immediately promote biomass co-firing in select existing (or recently closed) coal power plants would decrease the intensity of future wildfires in these regions and improve power plant emissions. This plan would also stimulate future forest health while simultaneously invigorating rural economies both near the power plants with logging and distant coal mining jobs. Such a program would increase or at least slow the rate of decline in near term coal use and be a tremendous public relations boost for the politically battered coal industry.
Bruce Beaver is a Professor of Chemistry at Duquesne University in Pittsburgh, PA