Is biomass-fired power generation carbon-neutral?

Tables 1 and 2 in the left-hand sidebar of this blog give hourly and so-far-daily snapshots of the energy sources that power Ontario’s electricity grid. As you can see, there are five fuel types: coal, gas, hydro, nuclear, “other,” and wind. The “other” category consists of eight generating units, four of which are at OPG’s Lennox station, which is a duel-fuel (oil and gas) plant. The other four are fired with wood waste.

If this graphic is true, then fossil-fired power generation is also carbon-neutral.

As you may have noticed, the Other category typically produces around 170 megawatts at any given time. (As I write this at four p.m. on Thursday April 11, it is producing 210 MW—for some reason Lennox unit 2 is producing 30 MW; Lennox rarely produces any power.)

And you may have also noticed that the tables show the Other category producing relatively low emissions of carbon dioxide (CO2) compared with the other emitting fuels, gas and coal. That is because one of the four non-Lennox generators in the Other category used to be gas-fired. When it changed to biomass, I did not change the carbon factor that generates the CO2 figures for the tables. That was because I could not decide if biomass really is carbon neutral.

It is a tricky question. Wood will eventually wind up in the atmosphere as CO2 anyway: it is eaten by fungi, which play an essential role in the natural carbon cycle. But that is just the point. Fungi are part of the natural carbon cycle. Is wood combustion by humans for power generation part of the natural carbon cycle?

7 comments for “Is biomass-fired power generation carbon-neutral?

  1. James Greenidge
    April 12, 2013 at 07:41

    Man, I wouldn’t even get started misleading the clueless public with another idealistic “green friendly” energy cycle scheme! Wood waste comes from harvested via fossil-fuel intensive methods so you’re ready in a energy deficient before you get the wood waste to the power planet (via fossil-fueled trucks) to burn — and Co2 isn’t the only hydrocarbon or gas released (cellulose elements, painted chips, etc) in the act of combustion. Were this wood chip cycle were that true you could safety and and happily burn wood chips in the ISS knowing you’d merely only have Co2 to bother with afterward and not, in addition to the gases, increasingly concentrated toxic ashes that’s not going to be treated as carefully as nuclear “waste”. Besides, say all Ontario’s power plants went wood; how long can they burn before they run out and start eating forests? Guess what we’re quickly back to! Neither problem even rears it’s head if you just go nuke. This isn’t an energy loop; it’s a parabola. Say my math’s wrong please!

    James Greenidge
    Queens NY

    • April 12, 2013 at 08:38

      James, no your analysis is not wrong. I think it is simply too much of a stretch to call biomass-fired generation carbon neutral. I do think it is an excellent use of forest-industry waste, though.

      On the bona fide pollution aspect of wood combustion: I know from personal experience — operating my cottage compound entirely on “biomass” heat during fall, winter, and spring months — exactly how “clean” wood is as a combustion fuel. It’s not clean at all: I have high chimneys to carry the CO and particulate laden exhaust away from where we all breathe. It’s handy, and “freely” available (provided I don’t factor in the labour required to “refine” it — i.e. fell dead trees, buck them up, saw into stove lengths, then split and stack). Perhaps most important, it is romantic and goes down swimmingly with urban female visitors, God bless them. But it ain’t clean.

      Ontario is such a silly place. No problem disposing of forestry waste via power generation, but woe to anyone who proposes similarly disposing of municipal waste via incineration or plasma gasification or simple combustion of landfill gas in generating engines (rather than flaring it off).

  2. Jeff Walther
    April 12, 2013 at 13:11

    Not really on point, but I do not see another avenue of contact. Steve, I really enjoy your blog, but your Tables 1 and 2 hang over about four characters into the text of your blog in Firefox under Linux. Specifically, I’m using Firefox 17.0.1 (but same problem under earlier versions) and Red Hat.

    Checking it out under IE and WinXP, I see that your tables have sharp, right angled corners. Under Firefox, they are wider and have rounded corners.

    I don’t know if it’s something which could be easily fixed, but if so, it sure would be easier on the eyes. The transparency of the tables makes it possible to read the text, but it’s kind of awkward with the blue lines running through the fourth character of every line.

    The city I live in, Austin, TX spent a ridiculous amount of money on a purchase agreement with a biomass power plant. Sigh. We could have had an expansion of the South Texas Nuclear Plant, with a guaranteed reduction in our CO2 emissions. Instead they spend all our money on stuff like that, and raise our rates, just to add injury to, well, injury.

    Keep fighting the good fight. I hope your rational words are reaching many people up there in the north.

    • April 12, 2013 at 13:18

      Jeff, thanks — another reader has the same issue. This template/widget combination does indeed produce that effect in Firefox and Opera under Linux. No problem with Chrome or Chromium. I’ll try to figure out how to fix.

  3. April 14, 2013 at 01:53

    I was looking at your CSS and if you make your #leftcontent width a percentage like 50% and give it left padding of 10px that might solve the problem.

  4. crf
    April 14, 2013 at 21:01

    I know nothing about this. But I’ll guess that it’s probably carbon neutral or even negative. The roots from the cut trees may have much of their carbon remain stored underground for the long term (millennia), rather than have it digested by bacteria or fungi and released. Perhaps that’s more than enough to offset the trucking/processing emissions.

    This is something that has to be studied in detail, and is likely varies by specific biomass project. It’s a bit like the argument about whether dams flooding forests are carbon neutral. (The dams store the logs underwater, so store carbon. But wait, the logs rot and release methane. But wait, etc, etc.)

  5. April 16, 2013 at 07:25

    I’d like to see the biomass-fired plants run their entire supply chain on RE.  This could mean converting the trucks to run on bio-oil produced by fast pyrolysis of wood, or building railways to bring biomass to the plants and powering them with the plant’s own electricity.  We’d see pretty quickly whether there was any net output.

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