Two weeks ago, the Manomet Center for Conservation Sciences released a report “Biomass Sustainability and Carbon Policy.” I’d been looking forward to reading the study, based on the caliber of authors and advisors. I anticipated that it would be a thoughtful evaluation of the pros and cons of biomass and the importance of what we call “smart bioenergy.” I personally saw it as an important resource guide for the current policy debate – to ensure that biopower and biofuels are actually beneficial. But, the next day I found a news report in my inbox “Mass. study: Wood power worse polluter than coal.” I was shocked to learn the article referred to the same report I’d just read.
We’ve read and discussed the report internally. From SACE’s perspective, the Manomet study offers an important new way to describe and think-through the possible impacts on the climate from biomass energy. Manomet raises interesting questions about the carbon neutrality of biomass and bioenergy. The analysis examines the “time-lag” that other researchers have observed, between release of biogenic carbon and re-uptake in forests. More importantly, the analysis examines which uses of biomass are most climate-friendly (i.e., heat vs. power vs. both).
The methodology of the study can be applied broadly to great benefit. Using concepts like “carbon debt” and “carbon dividend” and “pay-back” we have a new set of analytical tools to think about the real costs and benefits of biomass power for the global climate. Now, when a European utility buys Florida wood pellets made from whole pine trees, we have the tools to discern just how quickly (or slowly) forests will re-capture that carbon.
However, judging from the newswire reports, one might have concluded that some group of scientists had just made a stunning breakthrough of national and global relevance. But from what we read in the report, this could not be farther from the truth.
One concern we have is that the study is limited to Massachusetts, as even the Manomet Center has highlighted. Because New England forestry is so very different from that practiced in the Southeast, the Manomet findings have limited relevance outside Massachusetts and the Northeast region. Trees just don’t grow as quickly up there as they do down here in the sultry, humid Southern United States. Southern yellow pine forests are fundamentally different from New England’s hardwood forests. Also, New Englanders practice forestry on their thousands of acres very differently from Southerners on our millions of acres of forests. It’s no wonder the study concluded that the potential for biomass energy is limited in Western Massachusetts.
Every renewable energy resource has its appropriate place and scale. Would it make sense to build hydro-dams in a flat dry desert? Or wind turbines in the Atlantic Doldrums? If the developers of the Cape Wind project had proposed to build 468 MW of wind turbines in the middle of Florida, we’d have thought they were crazy. It’s appropriate, then, that the Boston-based American Renewables did not choose the Berkshire forests of Western MA as the site for their 100 MW biopower project — choosing instead to build in Gainesville FL (a project which SACE has endorsed).
For renewables, location dictates efficiency. And efficiency largely determines how quickly the climate benefits accrue. This is important because the climate crisis truly is about fixing the problem quickly. We’ve dawdled too long already. We already have evidence of our Southern climate changing. So we must be aware of how quickly each technology delivers climate benefits.
For example, we know that solar photovoltaics require about 1.5 to 3.5 years before they generate as much energy as it took to manufacture them. Wind turbines have an energy payback generally within the first year. Even the Manomet study recognized that biomass from forest residues (limbs and tops) used for thermal energy (to replace heating oil) can deliver a carbon “payback” within 5 years. (See page 7 of the Manomet study).
Granted, these different “payback” measures are not directly comparable, but they are analogous. The point is that there are no energy technologies without environmental impact. With regard to biomass, SACE certainly agrees with the New York Times article that said, “…in every case, the study found, much depends on what is burned, how it is burned, how forests are managed and how the industry is regulated.”
While the findings may be limited to Massachusetts, the study provides some very important tools and the methods ought to be applied in other regions to tell us precisely which kinds of biomass – and which bioenergy technologies – are actually helping fight climate change. However, a single study such as this should not define biomass policy, as some are urging in places farflung. Replicating the Manomet study’s methods based on faster-growing Southern forests may show biomass to be more climate-friendly here than in Massachusetts. One would expect different results in such a regionally-specific study, but the science must prevail. SACE urges Southern researchers to consider such a study.
Maybe it’s not so smart to build dams in the desert, windmills in the doldrums, and biopower in the Berkshires. But a total ban on biomass would be a mistake, in any state. The climate crisis is too urgent to throw-out possible solutions. We must find the smartest ways to implement all renewable energies, with the least impact possible.
This post was co-authored by Anne Blair.
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