Friday, March 12, 2010

Biomass crops bad investment for everyone

Every time I read about biomass and biofuel I get worried. Biomass is a fancy word for dried out plants. The word is used a lot these days to describe stuff that can be burned as fuel. There's also a lot of talk about biomass being able to substitute for fossil fuel use, and discussion about how biomass as biofuel releases less carbon dioxide into the air. (Carbon dioxide is one of the greenhouse gases that contributes to global warming)

On Wednesday, March 10/10 there was a 'green energy' conference in London, Ontario titled 'Growing the Margins'. (I'm not sure what margins are meant) The London Free Press newspaper had two short articles about the conference.

One article (1) was about how burning biomass was viewed as an alternative to dirty coal. Robert Lyng of Ontario Power Generation was quoted in the article as saying: '... when you compare biomass with other forms of alternative energy, it's not too bad'. He also mentioned that biomass produces less energy than coal and it's perhaps necessary to supplement it with natural gas in a generating plant.

To me, this does not sound like an endorsement.

The other article (2) talked about how 'the collapse of Ontario's tobacco industry presents an opportunity to grow new energy-rich perennial crops that could be used as fuel' and that the switchgrass and Miscanthus (another grass) grow well on the 'sandy soils of the former tobacco belt that aren't viable for many traditional crops'.

Well, when I looked up Miscanthus on Wikipedia (I know, not a full search ... but the Wik is usually a good start), it was described as 'rapid growth, low mineral content, and high biomass' and therefore good as a biofuel. But it went on to say that when it is burned the 'CO2 emissions are equal to the amount of CO2 that the plant used up from the atmosphere during its growing phase, and thus the process is greenhouse gas-neutral, if one does not consider any fossil fuels that might have been used in planting, fertilizing, or harvesting the crop, or in transporting the biofuel to the point of use. When mixed in a 50%-50% mixture with coal, it can be used in some current coal-burning power plants without modification'.

Does this sound to you like an endorsement of this Miscanthus as a fuel? It doesn't sound that way to me. Fossil fuel energy is used up in synthetic fertilizers, pesticides, and various pieces of heavy agricultural equipment and trucks to grow and ship a plant that isn't nutritious enought to be useful as animal fodder and not very useful as soil enhancer (if it were even left to decompose on the soil). And it has to be burned with a dirty fuel to do the job of another type of fuel.

No, this does not sound like a good idea to me.

From the first time I head about biomass and biofuels I've wondered what the effects are on soil health of not returning this biological mass to the soil ... meaning, if the leftovers aren't being left on the soil to rot and return nutrient and 'bulk' to the soil, surely this is a depletion of the soil health.

And I worry about the farmers who are being forced by economic forces to get into such crops. How much money are they going to sink into all the fossil-fuel based synthetic inputs and specialized equipment? What stress is there in experimenting with this new way of going into debt and gambling on market forces? And what does it take from them to fit their minds around growing crops only to see them burned up?

Just some things to think about. Best regards. Why's Woman

(1) Burning Biomass viewed as aternative to dirty coal. H. Daniszewski, London Free Press, March 11/10.
(2) Farmers Key to Green Energy. H. Daniszewski, London Free Press, March 11/10.

1 comment:

Craig said...

On the energy balance of giant miscanthus:

Miscanthus is perennial. Unlike annual crops (corn, for instance) it comes back every year. This means that the soil is not tilled up, releasing carbon into the atmosphere. More importantly, miscanthus goes dormant before it's harvested. This means that the nutrients and moisture go back in the ground, leaving just dry cellulose-rich stalks to be harvested. This means that you are not harvesting the nutrients and thus don't have to replace them each year in the form of fertilizer. It also means that the crop is transported almost dry--the moisture content is around 12%. That means that you're transporting almost pure plant, not water. Wood, by comparison, is over 50% moisture and that water is hauled and then (using fuels) dried before being burned or converted to fuel.

Miscanthus flourishes on marginal land and, as you can see above, requires very little inputs to grow.

Miscanthus is, indeed, GHG and carbon neutral, including the inputs and processing. It sequesters, in fact, over 40 tons per acre per year of carbon.

Don't fault the crop(s). Fault the US for not utilizing biomass in power generation. Millions of tons of wood pellets are exported to Europe from the US each year. These pellets then go in hoppers in Europe to be burned to produce electricity and/or heat for large-scale installations. Why? Because even after the processing and shipping, it's a better air-quality equation than using fossil fuels.