What to do with wood pellets?

Burning issues in BECCS and forestry

by Meron Tesfaye, PhD, senior policy fellow and Maya Glicksman, policy advisor

​​Trees are a key piece of the carbon removal puzzle—both as they grow and after they’re harvested. Recently, the use of wood pellets (portable, compacted sawdust) in the UK and EU’s renewable energy production portfolio has been steadily growing. Given the US’s status as the top wood pellet exporter, there are concerns over subsequent impacts to forest ecosystems — and their ability to remove carbon from the atmosphere. As we shape the role of wood pellets as feedstock for climate technologies, it’s imperative that we take a holistic approach when exploring the entangled issues of forests and bioenergy with carbon capture and storage (BECCS).

BECCS is a hybrid carbon removal solution that involves capturing carbon dioxide in plants, turning it into energy or fuel, and storing subsequent carbon emissions deep underground or in carbontech products. Bioenergy is the process of capturing CO2 in plants and turning it into energy, without capturing and storing subsequent emissions.

Both BECCS and bioenergy can use a range of biomass feedstocks (sources of energy, like wood pellets and crops) and conversion technologies (processes to generate energy, like direct combustion and pyrolysis). But since BECCS involves additional capture and storage of carbon, it has the potential to play a much greater role in climate mitigation than traditional bioenergy. In short, while bioenergy can reduce emissions, BECCS can remove them.

  • Biomass feedstock: Organic material (like forest residues and crops) that is used to create electricity, heat, or fuel
  • Wood pellets: A portable, compact, and energy-dense form of biomass commonly sourced from forest residues like sawdust and used as a feedstock
  • Wood-based bioenergy: Heat and electricity produced from forest biomass (like roundwood products and wood pellets) for residential and industrial consumption
Wood pellets are a compact form of forest biomass, commonly used to generate bioenergy. (Source: East Coast Lumber)

Both bioenergy and BECCS can use wood pellets as feedstock. Wood-based bioenergy makes up less than 2% of US energy consumption, so wood pellets represent a very small portion of domestic forestry products. Abroad, however, policies supportive of bioenergy in the EU and UK are increasing demand for US-sourced wood pellets. As a result, US wood pellet exports have grown 16% annually since 2012.

Given this trend, it will be important to identify ways to transition existing bioenergy facilities into BECCS plants for increased emissions reductions or carbon removal benefits. (And we have time to do this right — there are currently no BECCS facilities that use wood pellets, with the exception of a pilot plant in the UK.) But even with BECCS, we must be extremely cautious and intentional about how we source wood pellets.

Near-term federal and international policies will shape global wood pellet trading trends going forward. Retrofitting existing bioenergy facilities to BECCS plants is one immediate step, but further scaling BECCS requires full consideration of any possible adverse impacts on forests. Policies that support BECCS must simultaneously provide tools and regulatory guidelines for strong monitoring that ensures forest health and ecosystem protection.

As with any source of energy, we must account for the supply chain emissions of wood pellet use for bioenergy or BECCS from cradle to grave. However, US, UK, and EU policies classify the use of wood pellets for bioenergy as carbon neutral (and BECCS as automatically carbon negative). This is because they consider any biogenic carbon (or carbon derived from organic materials) emitted in the harvest process a “debt” that is “repaid” as source forests continue to grow and sequester carbon.

This perspective ignores local forest conditions that can alter management and harvest practices, regrowth rate, and carbon stocks. Researchers have found that the carbon intensity of bioenergy using wood pellets can be anywhere from 30% “dirtier” to 100% “cleaner” than coal, depending on forest carbon assessment perspectives, baseline scenarios, source of wood pellets, and rotation age. In short, not all use of wood pellets results in positive climate benefits.

To ascertain reliable and positive climate benefits, carbon accounting policies must better capture the complexities of regional biomass supply chains and localized ecosystem dynamics. Consistent carbon accounting tools, high-quality practice standards, and protocols must be developed to avoid divergent outcomes.

Market dynamics and incentives for wood pellets and forest management can also impact forest conditions and carbon storage. Forests follow a fairly predictable pattern: Young forest ecosystems are slow to sequester carbon at first, then increase exponentially to peak at middle age, then slow down to little or no additional carbon sequestered when they reach maturity.

Adapted from: Age-dependent forest carbon sink

The case for bioenergy states that forests should be managed in a manner that maximizes their carbon drawdown rates. Others promote preserving existing forests to reach their full ecological potential across biodiversity and carbon storage benefits — an approach known as proforestation. This whole-ecosystem approach places renewed value on old-growth forests and the carbon they store long-term, acknowledging the limitations of replanting and harvesting at scale.

Some argue that policies that support the use of wood pellets for current bioenergy and future deployment of BECCS increase forest carbon stocks by sparking investment in forest ecosystem management. Others question this stated positive impact on forest carbon, and instead propose a proforestation-only approach or support restricting wood pellet sourcing to forestry waste. For forestlands where BECCS and proforestation compete with each other, future financial incentives (or lack thereof) will play a huge role in determining how landowners choose to manage their forests.

To avoid incentivizing one carbon removal solution while hampering another, policy must enable landowners to choose from a complete menu of management strategies to achieve carbon removal goals in tandem with economic demands, ecosystem health, and community resilience needs.

The majority of wood pellet exports are sourced from the southeastern US, where forests are predominantly owned by families. While wood pellet industries offer additional employment opportunities and revenue streams for forest owners, facilities are disproportionately sited near socioeconomically disadvantaged communities and risk air and noise pollution to those already overburdened by it.

Policy must assess and account for real-world consequences for proximal communities, providing equitable economic opportunities and safeguarding from any possible harm as a result of bioenergy or BECCS. To ensure that future policies are both science- and community-based, robust research into these complex socioeconomic dynamics is needed.

Avoiding the worst impacts of climate change will require all of the carbon removal solutions at our disposal. Through policy, we have the power to shape how forest biomass like wood pellets is utilized to reach ambitious climate, ecosystem, and resilience goals, especially as strategies like proforestation and BECCS continue to garner public attention. Carbon removal policies that enable both forestry and BECCS must include robust carbon accounting, strong environmental safeguards, and incentives that provide for expanded economic options and improved health benefits for local communities.

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