Martha Walden
Anyone who walks in the forest knows there is a lot of dead wood out there. Rotting wood is good for the soil and wildlife habitat, but too much dead wood can be a fire hazard—a fearsome risk these days. Logging and thinning produce huge piles of slash, and the wind takes down a lot of trees that also become a fire hazard. Open pile burning emits carbon and soot, particulates, and toxic pollutants.
Removing fuels to make the woods safe would generate tens of millions of dry forest waste every year. What to do with this stuff? California wants solutions. AB 625, introduced by Representative Aguiar-Curry, ventures to deal with the fire hazard by treating wood waste as a resource to help the state achieve carbon neutrality by 2045. An ambitious twofer.
Several different biofuels, including renewable natural gas, cellulosic ethanol and hydrogen, can be manufactured out of wood. But the most common use for woody debris, of course, is burning it to make electricity. These fuels are called carbon-neutral or even carbon-negative because theoretically the feedstock would otherwise burn in an open pile or in a wildfire, releasing tons of carbon with nothing to show for it.
The first and biggest hurdle for all of these uses is the cost of transporting the material out of the woods. Let’s say we have an ethanol plant in Willow Creek. Wind has downed a lot of trees in surrounding areas that could be trucked to the plant, but how long before the trucks will have to range farther and farther to keep the works humming? Next thing you know, facilities that use wood waste as a feedstock but need to make a profit end up going after the forest itself. This is certainly true for wood pellet manufacturers and biomass electricity plants, though not all. (The biomass plant in Scotia burns mostly sawmill waste and some woody debris and non-merchantable wood.)
AB 625 doesn’t deal with this problem of transport. It mandates the collection of valuable data in order to quantify carbon emissions from fuel reduction activities. These standards are needed for the accounting requirements of the Greenhouse Gas Reduction Fund. It instructs the Air Resources Board to come up with a scoping plan to achieve the “maximum cost-effective reductions” in greenhouse gas emissions from using bioenergy to replace other fuels and to produce electricity. It also mandates training workers for different biomass utilization industries.
If the transport problem can be solved, and biofuels can be produced without cutting down the trees we all depend upon to sequester carbon in addition to so many other benefits, the steps outlined in AB 625 could promote non-combustion uses of woody debris. Unfortunately, the bill also wants to expand the Bio-MAT program which requires utilities to buy biomass electricity. Theoretically, this could mean renewable natural gas or green hydrogen that would spin those turbines to make electricity, but incinerating wood is simpler and easier. Nothing in 625 would change that.
The biomass biz is booming these days because no one knows how to stop it. Forests are clear-cut, the trees chipped and sent to utilities in Europe and Asia to replace coal. Coal is such a dirty carbon-intensive fuel that there’s only one thing worse we could burn, and that’s wood.