"Biomass" plants aka wood furnaces with a bit more marketing serve a political purpose. Renewables have an intermitence problem which will require a huge storage and peak load infrastructure solution to address it.

Until that problem is solved the "Biomass" wood furnaces and "Natural" Gas power plants serve the political purpose of allowing politicians to claim that they are ditching 'dirty' coal and 'dangerous' nuclear, those solutions will probably still create less CO2 emissions but they are by no means "green" or "eco" anything.

The problem with renewables is not power production but Power intermitence. Offshore wind farms can help but the scale of power that we consume will need a much deeper ground-breaking technical solution or a vastly greater power consumption reduction from consumers and industry, or both.

A large chunk of the Danish “green/renewable” energy comes from biomass plants when the wind isn’t blowing. So this is a debate we’re currently having, and it’s basically looking more and more like a legislative hack.

Biomass plants burn biomass instead of fossil fuels. We’re currently burning a lot of wood by-products from the Estonian lumber (timber?) industry.

I’m not big on the science, and I hope someone can put it better, but the arguing, as I understand it, goes something like: “the trees have absorbed CO2, so burning them is CO2 neutral”, but it’s not like burning wood stuff doesn’t release CO2.

I guess the main difference would be:

1. burning fossil fuel. Pulling carbon from within the earth and putting the CO2 in the air. 2. biomass burning. Burning Carbon that is above ground and putting in the air.

I think 1+2=bad, 2 by itself I don’t think is bad basically what the Native Americans used to do to maintain forests before Europeans. However, we don’t live in a world where we are just doing #2.

That’s not really how it goes though. We’re using it to make our numbers pretty so we meet the EU and Paris agreements, but it doesn’t actually make us a renewable country, and once the goals are met, political focus will go elsewhere.

It could be worse, sure, but that’s not an excuse for not doing better.

Right, you’d need to be positive that biomass is replacing what’s burned in order to call it neutral. On some drawn out time scales this is practically guaranteed, but in the short term it’s very easy to burn far too much without ensuring replacement occurs at a scale and speed that is sustainable.

I suppose you could use byproducts of selective logging where replanting is occurring and actively managed and maintained. Where I’m living there are forests that are quite well managed for lumber such that what’s removed will likely be replaced by the time logging occurs again. Using a similar practice for biomass plants could conceivably be called carbon neutral.

I have a feeling it wouldn’t generate nearly enough biomass conveniently or efficiently enough. I don’t know though. It must take incredible amounts of mass to generate useful amounts of energy.

“the trees have absorbed CO2, so burning them is CO2 neutral” is correct as far as it goes, but it completely ignores externalities and second-order effects.

If you burn biofuels you encourage people to clear-fell forests to grow biofuels, as happens in Indonesia and Brazil.

If you promote burning biofuels, you divert attention from cleaner alternatives (Solar PV, wind).

If you make a big deal about biofuels, you create the impression that nothing really has to change.

Biomass works when there already is a source of biomass around which otherwise needs to be taken care of, e.g. in areas with intense forestry, next to sawmills etc. As soon as you need to import biomass you're lost since a) this entails transports over longer distances and b) you loose the oversight on how that biomass is produced. This leads to insane situations like Stockholm importing biomass from the Americas.

Wherever plants grow, there is biomass created. With agriculture, it is all the parts of the plants which aren't eaten, be it by humans or lifestock. But the same applies for all natural plants growing. Left on its own, it would decay and emit most of the carbon content as CO2 anyway. Burning any available biomass for energy generation is basically CO2 neutral. Using available biomass as an energy source, is a good way of reducing the carbon footprint. However, there is only so much available, the ability to artificially increase the supply is extremely limited.

how limited? The growing season produces a pretty significant dip in global CO2, what if instead of burning it wholly, we pyrolysed it? That seems much better than carbon neutral.

There is only so much biomass we can extract from the biosphere without endangering it. It is limited to the amount what grows naturally. Actually, it is less, as the decaying biomass also plays an important role.

But yes, if we could extract the carbon from the cycle, it would be even better and truly CO2-negative. We should bury wood underground where it is not decaying for example.

Biomass is obviously CO2 neutral as long as it is replaced. The ratio between burned and used is of course important. Is 1:1 CO2 neutral? Probably not, due to losses and transport. Is 1:2, 1:3?

One of the claims in the video is that: If all of the trees in the United States (I think) were burned in these plants that it would power the United States (I think) for one year (I'm sure). Given that it takes more than 1 year to regrow all of the trees it seems like a foolish decision.

Apparently some of the plants also choose/have to incinerate vulcanized rubber (tires) to burn green/wet lumber.

Frankly, just using the documentary as my reference, this seems like an awful scheme and I can't fathom how subsidies and policy supported this technology.

Sure, but they aren't burning the lumber exclusively. If the timber is supplementing other power, then it wouldn't be depleting forests. Eg if you used 1/40th of all your timber every year, and replanted it all, you'd never run out assuming a 40 year timber cycle.

If solar, wind, hydro, nuclear, and grid storage cover most of the need, then biomass can certainly pick up some slack. And I'm sure there are plenty of industries that generate biomass as waste -- lumber, farming, etc. That waste would decompose into CO2, we might as well get some energy from it, right?

Seems like we're burning like half the trees in the us right now and powering nothing, tho.

The US has never been more forested in the last 150 years.