Biomass power

There is a big controversy in Maine about whether state funds should be used to prop up our biomass power industry. Part of the controversy is about if this is renewable or not. The plants used to sell a lot of this power to Massachusetts, where it can no longer be called renewable, due to a new law they passed. How does it compare environmentally to other forms of power generation? I know it is renewable, in the sense that you can farm trees to grow more wood.

Surely the point about biomass power is that they burn stuff that would otherwise go into landfill?

Originally, they were burning waste wood from paper mills, but most of the mills have closed. Now, they are cutting lumber for biomass power.

All looks pretty dodgy to me. If an industry is unsustainable it should look to diversify, not to the taxpayer, or customers to subsidise it. If electricity costs rise - energy hungry business will move out.

We have similar problems here with “green” energy. The taxpayer pays people to put up windmills that are pretty inefficient. The old power plants are still needed for when the wind doesn’t blow, so the taxpayer subsidises them too.

My daughter, a chemical engineer who works with power plant pollution controls, tells me biomass is a real problem because you don’t know what’s in it and have to control for many different pollutants.

The big advantage of burning biomass to produce electricity is that it’s (sort of) carbon-neutral. The trees absorb carbon dioxide out of the atmosphere, then burning the trees releases the carbon dioxide back into the air. There’s no net gain of carbon pollution.

Of course the downside is you’re clear cutting your forests. How big of a problem that is depends on your location, just how fast will a forest re-grow itself?

Of course the tax-payers have to support this operation, if these alternate sources of energy were competitive with fossil fuels, then we wouldn’t have the carbon pollution problems we’re having.

Most biomass grown for fuel is quick-growing scrub trees. They’re farmed much like any crop, just a bit slower: You re-plant the trees where you cut them, and in a few years those trees are ready to be cut again. It takes a lot of land, but it’s sustainable.

The same kinds of trees, and the same sort of agriculture, is generally used for paper production.

But if they’re now farming and cutting trees just to burn them as a biomass energy source, that sounds like a throwback to pre-19th-century wood burning days. So my electric stove, electric heater, microwave oven, and computer are all just run on (modern and somewhat upgraded) wood burning technology, just one step removed via some intermediate electric wires.

Sure. So?

It is a lot more efficient to burn a whole bunch of wood all at once to get a much higher-temperature source than you’d want to have in your home.

Of course, between your big fancy nuclear power plant and your electric grid is a modern and somewhat upgraded version of an olde-timey steam engine.

I’m having a hard time understanding this. Lumber is worth more than biomass in every market I’ve encountered. Lumber is the driving force for an efficient forest products industry. Biomass hardly pays for the transportation costs, it’s waste that can barely be utilized depending on the markets.

I don’t pretend to understand what Maine is doing, but speaking from my perspective in the natural resources industry, they seem to have built themselves a house of cards out of paper mills, logging and power plants and the taxpayers are the ones who will pay.

These scrub trees don’t generally produce valuable lumber.

I think you make a good point, however it does depend on the locality. Pretty much everything you said is true where I live. Hell, we even grind the waste brush up for particle board. Other locations this may be different. We need to keep all these options in mind and choose the best alternative to fossil fuels that suits our areas. Make use of what’s available locally.

I have done some work on this before and even led some grant projects. There are some misconceptions in this thread which I’d like to clear up :

Several problems with this statement :
1> Biomass needs water and fertilizer to grow. What about those impacts ?
2> The fuel needed to cut down biomass and transport to the plant is still fossil fuel - sometimes this fuel need is huge - so biomass becomes uneconomical
3> Not all parts of the biomass is harvested for use as fuel - the leaves and smaller branches which have low calorific value (but high transportation cost due to low density) are left to rot in the field. This rotting causes methane emissions - which are worse for the environment
4> When the harvested fossil fuels reach the plant, they need to be debarked and cut into smaller pieces and mud separated from it - all these processes use fossil fuels.
5> The cut pieces need to be dried - biomass has upto 60% by weight moisture. Drying again is usually done with fossil fuels.
6> Biomass drying releases a lot of volatiles into the air - these are usually phenolics and benzene - these have their own environmental problems and need more fossil fuels to burn to incinerate these pollutants (many plants just release them in the air anyways)
7> Water produced from condensing (drying water) often contains these hazardous chemicals (Phenolics and tars) - that are then “treated” or discharged into the wastewater.
8> The Ash content in coal is predominantly Calcium, Magnesium or Silicates or Iron. This ash has a high ash fusion point and does not readily form fly ash or corrode boiler tubes. The ash in biomass has some calcium but has a lot more potassium and sodium and causes corrosion problems and forms more fly ash.

Scrub trees are used to produce OSB (Oriented Strand Boards). Many houses have roofs made of these - and subfloors too.

That last quote was mine, not watchwolf’s.

And I don’t doubt that you can make some sort of useful product out of them, but it’s not going to be worth nearly as much as sawn 2x4s.

Sorry Chronos and watchwolf - I mixed up your posts.

No need to apologize to me hahahahahaha …

Most of your points above also apply to fossil fuels … transportation, processing, pollution … the coal fired electricity has all these problems as well. The main one you missed was the construction of the power plant itself, cooking the limestone to make cement and blast furnaces to make steel are just a couple of examples. Like I said, it would never work here in Western Oregon in spite a true abundance of wood fuel, there are far cheaper ways to produce electricity here.

The problem with growing crops for fuel is that it’s an unbelievably inefficient form of solar energy. Plants are only a few percent efficient at capturing the sun’s energy, then you have to harvest and burn, leaving you with practically nothing. Just build solar panels already.

It’s even worse for adding ethanol to gasoline: now you’re using food crops and thus raising those prices so the poor people of the world have a harder time buying food.

On the other hand solar panels, and the factories that make them, and the mines that feed raw materials into those factories, are not free or carbon-neutral either. Maintenance costs of a solar farm are substantial, while scrub grows itself without too much human effort, and under lighting conditions where solar panels would not be efficient.

I’d agree with that assessment for current ethanol production methods (especially American corn-based ethanol, which is a product of crop subsidies more than anything else). But if cellulosic ethanol becomes more mainsteam, we can then produce ethanol out of the part of the plant that we don’t eat, and food manufaturers can make fuel out of what would otherwise be waste.

Aren’t solar panels almost maintenance free? I have read that they can run for decades without maintenance. Sure, if a storm breaks them, or a criminal steals parts of the system, they will need maintenance. But they are mostly just set and forget.