Pelleted by pollution: Why wood biomass is a false solution to the climate crisis

April 23rd, 2009 was an important day for Europe. On this day, the European Commission passed the Renewable Energy Directive, which required that Europe as a whole must produce 20 percent of its energy from renewable sources by 2020. This law is one of the reasons why Europe continues to outpace in the United States in renewable energy development. 

But a little secret was buried deep within the pages of the expansive statute. The Commission designated biomass, the burning of wood pellets to generate electric power, as renewable energy. The ramifications of this seemingly innocuous decision are still being felt around the world. 

Soon after the directive was passed, wood pellet processing plants began to pop up around the Southeastern United States. Now, the U.S. is the largest exporter of wood pellets in the world with 90 percent going to Europe, if you include the United Kingdom. 

Despite the hype around biomass as a "nature-based solution" to climate change, the biomass industry is defined by its rising emissions and the pollution it adds to disadvantaged communities. As forests throughout the Southeastern U.S. continue to be felled, lawmakers around the world must ensure that the biomass industry cannot access tax incentives reserved for clean energy. 

The way that the biomass industry works is simple — cut down trees, process them into pellets and burn them. The heat generated from burning the wood pellets turns water into superheated stream, which then turns a turbine connected to an electrical generator that electrifies our homes, schools and factories. Biomass is such a popular strategy for European nations to meet their renewable energy targets because it can use the exact same infrastructure of coal-fired power plants. All a company needs to do is to start burning wood instead of coal in the boilers of its power plants. A prominent example of this is the Drax Power Station in the U.K., which has been feeding biomass into four its 645 megawatt (MW) coal boilers since 2018. 

Though biomass is considered renewable due to its ability to grow quickly and derive energy from the sun, this does not mean that it lowers carbon emissions. Because wood pellets have a lower energy density than fossil fuels, they emit 50 percent more CO2 per unit of energy produced than a coal-fired power plant. In addition to the emissions that occur during combustion, forests lost their ability to sequester carbon when they are cut down. 

Despite this evidence, the biomass industry continues to assert that their operations are carbon neutral or even carbon negative. They argue that because the trees are taking carbon out of the atmosphere during their lifetime, burning wood pellets simply releases that same carbon back into the atmosphere, resulting in no net contribution to climate change. Furthermore, by adding carbon capture technology  (essentially a big machine that removes carbon from a smokestack) to biomass-fired power plants, little to no CO2 is released during combustion, resulting in the net sequestration of carbon.

This logic is flawed for multiple reasons. First, it assumes that felled forests will regrow and store the same amount of carbon as the trees that have been cut down. In reality, it takes saplings decades to match the levels of carbon absorption that mature trees achieve. Second, it implies that corporations will continue to replant timberlands after they have been cut down. It is not guaranteed that this will occur, whether it be due to economic considerations or ecological challenges such as wildfires. Third, the simple arithmetic on a carbon balance sheet does not account for the other forms of pollution, such as volatile organic compounds (VOCs), nitrous oxides (NOX) and particulate matter (PM), generated from both biomass-fired power plants and wood pellet processing facilities. Fourth, the biomass industry has an extremely long and carbon intense supply chain. Pellets, which are bulky commodities, must be shipped from the U.S. to power plants thousands of miles away in Europe and Asia.

This argument isn’t constrained to environmental circles. Drax Group, which operates the biomass plant in the U.K., was dropped from the S&P 500 Clean Energy Index after financial analyst cast doubt on whether the company truly realized emissions reductions over fossil fuels. 

From a land use perspective, the inefficiencies of burning biomass for electric power become even more apparent. In essence, biomass turns solar energy into electrical energy. To do so, the tree must absorb the solar energy via photosynthesis and incorporate this energy into its chemical bonds. Then, the tree must be burned, turning this chemical energy into thermal energy, which in turn becomes mechanical energy that is again transformed into electrical energy. All these conversions waste energy, resulting in a 0.3 percent efficiency. 

However, we do have a technology that can convert solar energy into electricity in just one step — solar panels. Because solar photovoltaics (PV) only require one step to send electrons onto the grid, their efficiency averages at 21 percent. Though this metric can be improved upon, solar is lightyears ahead of biomass. In fact, solar PV can generate 100 times more energy per hectare than biomass. 

Efficiency is not the only area in which biomass performs poorly. Earlier this year, Enviva, the world's largest producer of wood pellets, filed for Chapter 11 bankruptcy. Despite 2024 being a year of record demand for the wood pellets, Enviva is still racking up losses due to faulty equipment that is unable to cope with tough pine resin. The company’s best shot at survival is securing tax credits from the Inflation Reduction Act (IRA) meant for clean energy technologies. 

The U.K.’s largest biomass consumer, Drax, has made a living off government subsidies. By utilizing two programs meant to stimulate renewable energy development, is projected to receive £11 billion ($13.9 billion) in subsidies between 2012 and 2027. On the other hand, wind and solar are now cheaper than natural gas in the U.K., limiting their reliance on subsidies. Biomass’ inefficiency isn’t just environmentally destructive, it’s also bad for business. 

In today’s global economy, biomass policies made in Europe have tangible impacts halfway across the world. Now, communities across the Southeast US, the global hotspot of biomass production, must endure the noise, pollution and traffic emanating from pellet mills. Pellet mills are predominantly located in rural, low-wealth communities of color, continuing a pattern of environmental injustice. As a result, residents can no longer enjoy the outdoors without inhaling dust and soot and experience disproportionately high levels of illness. 

It is critical that the biomass industry does not receive IRA tax credits as it is not an effective climate solution. In Europe, the E.U. needs to strengthen its criteria around biomass sourcing, eliminate subsidies for biomass and conduct a more rigorous assessment of biomass’ life-cycle carbon emissions. And in the U.K., renewable energy subsidies should only go to technologies that are proven to emit less carbon than fossil fuels. 

Disincentivizing biomass burning does not preclude forestry from playing a key role in the energy transition, such as with the construction of mass timber structures. However, by needlessly burning trees to produce paltry amounts of electricity, we are wasting this valuable resource. Trees are one of our greatest assets in fighting climate change — it would be wise to keep them around for a little while longer. 

Aaron Siegle is a Trinity junior. His pieces typically run on alternate Fridays.

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