The concept behind wood-based biomass energy production is relatively simple: take forest debris, incinerate it, and use the released energy as a power source. Its large-scale usage, however, is often ethically tricky. In the best-case scenario, biomass could be a tool to address bad forest practices and help in the energy transition by producing baseload electricity or fossil fuel alternatives such as hydrogen. In most cases, however, using biomass for energy production can harm public health, incentivizes forest overharvesting, and contributes large quantities of greenhouse gas emissions (GHG) to an already burdened atmosphere.
Understanding the pros and cons of biomass is tricky. It requires nuance, a case-by-case approach, and the dissemination of science and conflicting information. We at EPIC have broken wood-based biomass into three admittedly over-generalized, but still useful categories: the Good, the Bad, and the Ugly.
The Good: Sustainably-Fed Micro-Plants
Let’s start with the best-case scenario. After centuries of systematic forest mismanagement, through means of fire suppression policies, clear-cutting, plantation creation, and overall gross negligence, our forests have become overloaded with fuels. To avoid high-intensity wildfires and push for healthier forest ecosystems, thinning operations generally use pile burning to reduce fuel levels. This fuel reduction is often considered a prerequisite to reintroducing low-intensity burns into the landscape.
The energy that is currently released into the atmosphere during these localized, small thinning projects could potentially be harnessed to help power nearby rural communities through small-scale biomass plants. When, for example, transmission issues arise, and renewable energy options such as solar and wind drop out of the grid, these micro-plants could be used to generate a baseload of electricity.
Because pre-commercial thinning has historically not produced a merchantable product, these projects all have had to be paid out of pocket. The U.S. Forest Service has packaged pre-commercial thinning projects with commercial timber operations to help pay for the pre-commercial work. Small, local biomass plants could therefore provide some money to help offset the costs of this type of forestry, both saving money and reducing pressure to log for profit.
Public health concerns regarding air pollutants and carbon emissions would remain, but the alternative to pile burning is also associated with similar side effects. More importantly, these energy sources’ minor, localized nature would also result in little risk of over-thinning forests compared to their large-scale counterparts.
The downside: small-scale biomass is mostly conceptual, as the costs to operate are high. Federal and state subsidies may make this a more viable tool in the future. There is also still the risk that once an investment is made to create a biomass plant, that facility would need to be fed in perpetuity, risking that energy production could force bad logging practices.
The Bad: Large-Scale Energy Dependence
Over the past 30 years, California has increasingly grown dependent on large-scale biomass facilities to supply a percentage of "renewable" energy units to the grid. While carbon emissions from biomass are part of the natural carbon cycle, unlike fossil fuels that put new carbon into the system which had been previously sequestered, the emissions from biomass are still considerable and are working to drive climate change now. Carbon emissions per energy unit produced from biomass are larger than that of coal. The fundamental importance of curbing emissions in the short-term means that large-scale biomass should not be heavily relied on in the green energy transition.
One example of biomass we should work to move away from is the Humboldt Scotia Biomass Power Plant, which produces energy from Humboldt Sawmill Corporation's timber waste. The plant provides around 15 percent of Redwood Coast Energy Authority RePower energy portfolio and is rated for around 30 megawatts (MW). It is also one of the greatest carbon emitters in Humboldt County, emitting far more carbons per energy unit compared to Humboldt Bay’s natural gas facility. Additionally, Humboldt Sawmill has frequently and periodically violated air quality regulations, emitting harmful, cancer-causing pollutants into the Scotia neighborhood and beyond.
To reduce these toxic emissions and address the climate crisis, the Scotia biomass plant will need to be phased out. How that happens—and how fast—is a question for public debate. A successful shutdown requires an operational alternative that prevents waste from turning into landfill emissions. That could be large-scale composting, other wood products, biochar, or a cleaner, more efficient hydrogen production plant. For that to happen, however, decision-makers must incentivize alternative ways to dispose of that mill waste now.
The Ugly: Poor Forest Management
Large-scale biomass schemes are uncomplicatedly bad ideas. Because the energy density of woody debris is relatively low compared to its coal cousin, trucking thinned forest debris over long distances is financially unfeasible. Therefore, a large facility that can consume a lot of residuals would require extensive tree-cutting within a certain radius to remain economically profitable. At EPIC, we see this as incompatible with responsible forest management practice.
A proposal brought forward by Golden State Natural Resources (GSNR) would build two new pellet plants in Lassen and the Sierras to process biomass into pellets (a more energy-dense form of wood) to ship across the seas for energy purposes. These proposals all but guarantee to contribute to greenhouse gas emissions heavily, resulting in bad forest management practices by creating the need to feed the beast — all while providing little benefit to local communities. Large-scale biomass, such as the GSNR plan, will likely never be effective, and EPIC is committed to fighting against it.