UK Climate Advisor: Wood-Fueled Power Plants Bad for Climate

The UK shouldn’t be burning trees for electricity. Sure, I would say that. But in good news, that’s also the conclusion of the UK government’s official climate advisory board, the Committee on Climate Change. In a new report, the independent panel highlighted the dangers to the climate from biomass use in energy production broadly, and electricity generation in particular. It recommends ending support to large-scale biomass-fueled power plants that are not fitted with carbon capture and storage technology, known as BECCS.

This is a significant development for the world’s largest user of biomass for electricity (biopower for short) for two reasons, and it should be heeded by other countries thinking about following the UK down this path. First, it recognizes that unabated biopower is a false climate solution, as scientists have warned for some time. This is especially true when the biomass fuel comes from forests. Second, it further crystalizes the challenging economics for large-scale biopower compared to genuine zero-carbon power sources like solar and wind (spoiler alert: biomass can’t compete).

Biopower plants that burn wood from forests, such as Drax Power Station, generate climate pollution in two places: (a) at the smokestack where burning biomass results in more carbon pollution than burning coal; and (b) from the land, where increased wood harvesting replaces mature forests with young saplings, reducing forest “carbon sinks” and foregoing carbon sequestration (a fancy term for trees growing and sucking carbon out of the atmosphere) that would have otherwise occurred.

Current UK legislation only accounts for a sliver of the full lifecycle impacts of biopower plants; it ignores the harm to forest carbon stocks resulting from harvesting wood for energy production. The climate committee warns that without significant reforms, reliance on the large-scale biopower risks worse outcomes for the climate than using fossil fuels. Again, we’ve been arguing this point for years, but it’s a critical admission coming from the UK government’s official climate advisory board.

Analysis shows that the wood pellets burned by Drax increase carbon pollution for decades compared to coal and natural gas. To its credit, the committee underscores that “unsustainable or high-risk feedstocks,” such as “stemwood,” (industry jargon for whole trees and large-diameter wood), which it identifies as a high-carbon source of biomass, “should be regulated out” of the UK market. [Separately, the processing and shipping of wood pellets uses a lot of fossil fuels and releases a lot of carbon too, and as I discussed here, Drax’s pellet imports would not qualify under the UK’s new emissions intensity guidelines. Unfortunately, the UK grandfathered in the old Drax plants.]

The addition of CCS to a wood-burning power plant is not a magic climate fix that makes this pollution disappear (though unfortunately, many in government have fallen for the mythology that it will). While the technology for capturing and safely storing carbon dioxide underground is widely demonstrated and mature, and the practice can be safe if appropriately regulated, the climate impacts of BECCS are equally subject to the carbon accounting rules that apply to unabated biopower.

As the climate committee implies with its recommendations for reform, the UK’s current biomass supply chain is high-carbon. Adding CCS may shift UK biopower plants down the climate emissions curve, but it does not guarantee any particular emissions outcome, much less a “carbon negative” power station, as claimed by Drax. That’s because CCS can only capture smokestack emissions; it cannot mitigate impacts to carbon stocks on the landscape or forgone sequestration in the forest. The type of biomass fuel burned still makes an enormous difference. And as long as Drax continues to burn high-carbon biomass (read: trees), its power stations cannot be considered “green,” with or without CCS.

And then there’s the issue of cost. A 2017 analysis that examined the costs of meeting the UK’s new electricity needs found that not only can solar and wind meet those needs as the country phases out coal, but they can do so more cost-effectively than new biomass, even accounting for the costs of integrating solar and wind into the grid.

Adding CCS technology will raise the costs of biopower plants even further. (How much will depend on the size of the plant being retrofitted, its efficiency, and its proximity to CO₂ pipelines and suitable storage opportunities, and other factors). Drax already receives £2 million per day in subsidies to operate its coal-to-biomass conversions—essentially a massive taxpayer-funded bailout of the UK’s largest coal plant. These subsidies are scheduled to run out in 2027 and the company is already positioning itself to ask for new subsidies for CCS.

No forest biomass should be going to large-scale electricity generation in the UK. The day its report was released, the climate committee’s chair Lord Deben echoed this conclusion, telling reporters that the UK has to be “very careful” to use biomass only where there are few alternatives. “You don’t burn it in boilers; you use it to make aeroplane fuel,” he said.

But just as the UK’s existing biopower program is based on flawed carbon accounting, so would be any future program to extend the life of these plants with CCS under the false guise of delivering negative emissions. The government should not throw more good money after bad by subsidizing Drax to retrofit its biomass plants.