According to a Granite Geek (Concord, N.H., USA) as you may have heard, there is great debate at the moment about how and whether to support biomass energy, a fancy term for burning chopped-up trees to generate heat and power.

The debate centers on a complex tangle of economic questions involving jobs and costs. But there’s also an environmental side to it, which is just as tangled.

Here are what years of reporting on the question has led the author to believe are the three key points in deciding whether biomass energy should be seen as environmentally "good" or "bad." In New England, the majority of the biomass burned for power and heat is pretty sustainable, mostly consisting of trees or the portions of trees that can’t be turned into more profitable lumber or firewood. Since the trees would have been cut anyway, the damage is minimal – although it’s not zero, because leaving behind leftover bits of the harvest, known as "the slash," can help wildlife and long-term forest health.

This contrasts to the Southeast, where huge timber farms have been developed to feed Europe’s desire for wood pellets. As with many large agricultural systems, economic wishes override environmental concerns and many people are concerned about turning forests into the arboreal equivalent of a monoculture. That system is very unlikely to ever happen up here, however.

There’s also the climate change argument. Biomass is recyclable over 20- or 30-year periods, if done properly. A big reason many support biomass power is that trees can be regrown and remove the carbon from the atmosphere that was produced when we burned their predecessors – something you can’t do with oil or coal.

As for how the wood is used, burning it to produce electricity, as compared to producing heat or both electricity and heat in what is known as "combined heat and power," is the least effective use of biomass. That’s a strike against most of the state of New Hampshire's (author's home-state) existing biomass power plants, which have no obvious method to make use of their waste heat. This is particularly bad because wood is not very energy dense in its raw form, meaning operations have to burn a lot more of it than we would of fossil fuels to produce the same energy.

The author noted at this point that we’re getting into the land of the hypothetical, but where he also believes the reader may find the strongest environmental argument in favor of supporting biomass energy.

Foresters argue that the extra income from biomass energy is important if we want our forests managed properly. And our forests do have to be managed, whether we like it or not. Centuries of logging and burning and acid rain and invasive species and climate change mean there are no natural forests anymore, not even deep in the Pemigewasset Wilderness.

Without biomass income, foresters say they will have to start "high-grading" woodlots, in which every single good tree is cut to cover costs, leaving weakened, inferior forests that aren’t good for wildlife or carbon sequestration. Or else they won’t bid on forestry jobs at all, which sounds good but isn’t.

If woodland owners can’t get income from a local timber harvest every couple of decades, they’ll have much more incentive to sell the land so something can be built on it, which is the worst case from an environmental point of view.

Right now every megawatt that biomass doesn’t produce in the author's home state New Hampshire is reportedly replaced by, on average, about four-tenths of a megawatt of electricity generated by natural gas, a quarter megawatt produced by atomic power, one-sixth of a megawatt imported from outside regions, and roughly one-sixth of a megawatt from renewables including wind, solar, hydropower and burning trash or landfill gas for energy. Only a couple percentage points of our electricity comes from burning coal and oil any more, a specifically cited "surprise" to many citizens who would think otherwise.

Some biomass proponents argue that wood-based electricity, especially when its mostly local wood as it is in New England, is a relatively benign way to cover gaps in baseload power as we transition to renewables. Without biomass, they say, it will be harder to work our way out of dependence on fossil fuels because more money will flow by default to natural gas.

So is burning wood for power and heat a good thing or a bad thing?

First, the author shares his own cautionary note: In 2016 he wrote that it "was good" and in the next year, 2017, he wrote that it was "not so good", so, by his own admission, you may want to take any current conclusions offered with a grain of salt. This could more realistically be a testament to how difficult understanding the comprehensive time-inclusive effects of biomass is on the environment as a renewable energy segment that must be studied generation-by-generation as determined based on the ability of managed forests and fiber plantations to successfully adapt their operations towards maximum efficiency and the fastest and most complete forest renewability and revitalization in subsequent generations of tree harvests that can possibly be achieved so as to also harvest managed fiber material land sources in a way that processes trees in a total and absolute capacity between cooperative bioenergy operations collecting more-sustainable residues from the plentiful bark / small branch leftover of lumber as used by industries requiring quality wood chips such as for the P&P & related industries in quality tissue and luxury pulp and top-notch graphic paper production dependent on an ongoing source of satisfactory wood chips supplying a consistent virgin wood-fiber input as the principal raw material in paper product preparations.