Sustainable Development Goals
Buena Vista Biomass Power, Brahma, UC Berkeley Center for Forestry, United States Forest Service (USFS) Rocky Mountain Research Station Missoula Fire Lab, and UC Davis Biological and Agricultural Engineering, Blodgett Forest Research Station (BFRS)
Due Diligence Services, Feasibility Studies, Plant Efficiency Upgrades, Supply Chain Management, Carbon Management, Component Supply
Large regions of Sierra Nevada mixed conifer forests are in need of hazardous fuel reduction treatments to reduce the risk of high severity of wildfire and return forests to fire-resilient conditions. Whether as a complement or replacement to prescribed burning, it is highly desirable to increase the pace and scale of these treatments. Significant quantities of woody biomass wastes are the unavoidable byproduct of these treatments.
Open pile burning in the forest is most commonly used to dispose of woody biomass waste, as fire hazard reduction objectives prevent leaving the material in-field to decompose, and because in many cases it is the most economically viable option. While woody biomass wastes represent a significant renewable energy resource, the cost to process and transport the material for use as fuel to produce electricity (or use for other value-added bioproducts such as biochar, biofuels, polymer precursors, or thermal energy) often exceeds the value of biomass electricity generated at the plant when considering the avoided cost to pile burn, and the potential value of nutrients returned to the soil (which is low due to the localized and limited pile burn location). A significant drawback of open pile burning is that it generates emissions of criteria air pollutants (particulate matter, carbon monoxide, volatile organic compounds, and nitrogen oxides), greenhouse gases (GHGs), and air toxins such as polycyclic aromatic hydrocarbons and aldehydes.
The Placer County Air Pollution Control District sponsored in cooperation with the UC Berkeley Center for Forestry, United States Forest Service (USFS) Rocky Mountain Research Station Missoula Fire Lab, and UC Davis Biological and Agricultural Engineering a case study to quantify the energy, air quality, and GHG benefits, as well as the economics, of utilizing woody biomass wastes generated at Blodgett Forest Research Station (BFRS) for renewable energy at the BVBP facility as an alternative to the status quo of open pile burning.
This facility was originally designed to burn lignite coal but closed in the mid-1990s. As subsidies decreased the project owners sought to change from paying for lignite (with subsidies) to being paid to take waste biomass. After the completion of an Environmental Impact Report, the proposed repowering of the facility was active again in 2009, with plans to repower it with "clean urban wood, agricultural byproducts from orchards, and material from the forest.
The Buena Vista Biomass Power (BVBP) Facility is an 18-megawatt wood-to-energy plant that generates electricity from approximately 100,000 metric tonnes of woody biomass each year. BVBP produces indirect benefits related to fire fuel management and reduces the potential for catastrophic wildfires. The project reuses and retrofits an existing coal-fired power plant adjacent to the existing landfill. The plant’s feedstock includes agricultural wood waste (e.g., orchard prunings), urban and construction wood waste, and debris from forest thinning activities in nearby National Forest lands. In order to upgrade the facility, an assessment of the impacts of construction and operation of the facility was required, including land use, air quality, GHG emissions (including whether or not the facility is carbon neutral), noise, truck traffic, water supply, sustainable forest practices, and biological resources. Key concerns raised by the public were the air pollutants and GHG emission balance of the project and the project’s potential influence on forest health.
As a part of this project and as an alternative to open pile burning, the use of forest wastes from fuel hazard reduction projects, BVBP worked with the Blodgett Forest Research Station on a keystone study. Electricity production was shown to produce energy and emission benefits: energy (diesel fuel) expended for processing and transport was 2.5% of the biomass fuel (energy equivalent); based on measurements from a large pile burn, air emissions reductions were 98%–99% for PM2.5, CO (carbon monoxide), NMOC (nonmethane organic compounds), CH4 (methane) and BC (black carbon), and 20% for NOx and CO2-equivalent greenhouse gases. Due to transport challenges and delays, the delivered cost was $70 per bone dry ton (BDT). This comprised the biomass feedstock collection, processing ($34/BDT), and transport ($36/BDT) for 79 miles one way which exceeded the biomass plant gate price of $45/BDT. Under typical conditions, the break-even haul distance would be approximately 30 miles one way, with a collection and processing cost of $30/BDT and a transport cost of $16/BDT.
Revenue generated from monetization of the reductions in air emissions has the potential to make forest fuel reduction projects more economically viable. BVBP is a clean-burning biomass plant designed to output 18MW of baseload electric generating capacity. The BVBP facility produces electricity by burning urban and agricultural biomass waste in a circulating fluidized bed (CFB) boiler. One advantage of CFB boilers is that it is possible to combust very high moisture content fuel compared to a traveling grate design. Also, the design provides complete combustion, which emits low air emissions. Additionally, BVBP utilizes an SNCR, Limestone Injection, and a Baghouse for criteria pollutant emissions controls
Energy production and reductions in criteria air pollutants and GHG emissions were quantified from the utilization of forest woody biomass wastes to fuel electricity generation as an alternative to open pile burning. However, biomass energy project economics are challenging due to the inefficiency associated with feedstock processing operations and the long transport distance between biomass origins and the location of the energy facility. Improvements in processing and transport efficiency are key attributes in bridging the gap with low electrical sales prices.
However, the sale of greenhouse gas and criteria air pollution reductions as mitigation offsets to meet environmental review requirements (such as those under the California Environmental Quality Act) would help to make forest biomass projects more economically viable. A potential greenhouse gas value of $20/ton CO2-equivalent (the approximate rate of credits under South Coast Air Quality Management District Rule 2702, Greenhouse Gas Reduction Program) would add $10/BDT to the biomass value and significantly improve the return on investment for the BFRS-BVBP project by 50%. Monetizing criteria for air pollutant reduction benefits under California’s Carl Moyer Program, mitigation of NOx, NMOC, and PM2.5 is valued at up to $16,000 per ton. There is a growing demand for such emissions reductions as air quality standards tighten and economic growth in rural air basins continues. For instance, new businesses and land development projects that generate emissions are often required to mitigate their impact under the California Environmental Quality Act review process or purchase emissions reduction credits to meet New Source Review requirements under the federal Clean Air Act. A video documenting the BFRS biomass project was produced that includes interviews with a unique and diverse set of resource professionals, researchers, state and federal agency representatives, utility representatives, and elected officials.
While the State of California is very supportive of biomass projects and clean energy. The State is going to need to do more to support the biomass industry and specifically the forestry sector which is in dire need of better forestry management options for controlling forestry debris and forest floor management as witnessed by the most recent forest fires in California. Some of the benefits realized include the following: