As Virginia seeks to reduce CO2 pollution from the power sector, it’s an open question – how to regulate emissions from biomass energy?
The good so far: the state’s
proposed carbon trading plan will require plants that co-fire biomass with coal to buy allowances for all the CO2 they emit – even the CO2 from burning wood.
The bad: the plan doesn’t cover the several “stand-alone” wood-burning plants owned by Dominion, or the plants that burn fossil fuels and biomass in the “industrial” sector.
To effectively reduce emissions, DEQ should cover all facilities in the power sector that emit carbon (see our detailed comments submitted to the state, co-signed by allied groups, and our Washington Post op-ed with the Sierra Club about how bioenergy should be covered).
Dominion, as usual, is on the opposite site. They
claim their plants burn biomass “primarily derived from waste wood, the smaller tree tops and branches left behind in the forests as part of the logging process for roundwood,” thus biomass energy should be treated as having zero emissions because letting the wood decompose emits the same amount of CO2 as burning it.
While Dominion’s assertions are dubious (the company
has stated that its definition of waste wood includes “small trees”), a new peer-reviewed study shows more clearly than ever that biomass energy will undermine efforts to prevent climate change – even under the best-case scenario where plants burn residues (“Not Carbon Neutral: Assessing the net emissions impact of residues burned for bioenergy,” in Environmental Research Letters).
DEQ wants to reduce emissions by 30% by 2030. That can’t happen if Virginia’s plan doesn’t cover the biggest carbon polluters.
It’s great that DEQ hasn’t fallen for biomass industry arguments, and is requiring plants that co-fire biomass to buy allowances for all the CO2 they emit. But Virginia’s power sector emitted over 49 million tons of CO2 in 2016. Between DEQ’s exemptions for utility-scale wood-fired plants, industrial plants, and waste incinerators – as well as the fact the plan doesn’t cover plants that are less than 25 MW – at least a quarter of these emissions aren’t even covered under the cap.
It makes sense to regulate big wood-burning power plants, ideally by counting all stack emissions. But DEQ could regulate them with a concession to the biomass industry: count biomass net emissions. That’s the difference between CO2 emitted by burning biomass, and the CO2 it would have emitted had it been left to decompose, or been incinerated for disposal without energy recovery. In cases where incineration is the alternative fate, net emissions are zero – providing a functional, but science-based, rationale for excluding emissions from industrial plants burning black liquor.
That means treating biomass burned in Virginia as if it’s residues, not whole trees, where the carbon impact is greater. And since we know that Dominion likes to pretend whole trees are residues, that means this framework would still underestimate emissions.
But it would be much better than treating emissions as zero, which is the functional outcome of exempting wood-burning power plants under the carbon trading plan.