California is experiencing what has been dubbed the worst epidemic of tree mortality in the state’s modern history, with the death of an estimated 66 million trees since 2010. There seems to be widespread – but not unanimous – agreement that leaving close to 40 million dry tons of wood in the forest will increase wildfire risk to unacceptable levels. A tree-mortality task force is working to safely remove the dying trees by using the tree services where some of which can be harvested for timber. But given the current trajectory, lots of wood will be burned on-site. This begs the question: are we better off using this biomass to generate electricity?
Teams of researchers have been documenting the costs of biomass generation versus “non-utilization” burning (i.e., on-site burning to reduce fire risk). Overall they find that, unless trees are located quite close to biomass generation facilities, the cost of extraction, processing, and transport to biomass generation facilities exceeds the market value of electricity generation.
Some stakeholders argue that current market prices and policy incentives are failing to capture the benefits of biomass generation. Some argue that biomass generation affords the added benefit of displaced CO2e emissions in the electricity sector. But in California, CO2e emissions are regulated under a suite of climate change policies, some of which are binding. If, for example, the aggregate share of renewable energy generation is set by binding regulations, an increase in biomass generation may change the mix of fuels used to generate electricity, but not the level of CO2e emissions.
Importantly, burning wood at biomass facilities (versus in open-piles or incineration) releases lower levels of other harmful pollutants like particulates. It is not clear how differences in emissions rates translate into health and environmental damage costs, but accounting for these environmental costs would presumably reduce the net cost of biomass generation relative to the more polluting alternative.
Increased support for biomass energy makes sense if the benefits justify the added costs. On one hand, burning more wood at biomass facilities will incur additional operating costs. On the other hand, it will generate less local air pollution as compared to non-utilization burning and other potential benefits. Getting a better handle on these costs and benefits will be critical if we are going to make the best of this bad situation.
This post was adapted from the Berkeley Energy Institute Blog. Original post can be viewed in full here.