My wife and I consumed about $2000 worth of energy this week and in the end, all we got out of it was a wienie roast (but a damn fine wienie roast!). However, what we actually spent on the $2000 worth of energy we consumed was 8 cents.
It turns out the US Government and private individuals own huge amounts of free-for-the-taking energy, and in fact taking it would be the environmentally sound thing to do. Beyond that, it takes virtually no new technology to utilize this energy.
Unlike other free energy schemes, this one requires no tinfoil hats. Read on ...
Let's clear up the free $2000 wienie roast first. We spent the weekend doing what George W Bush likes to do - cutting brush (although we call it 'reducing fuel loads'). We burned one pile of leftover logging debris ('slash' -stumps, branches, unwanted trees) that we stacked last fall - our property was logged 20 years ago, before we bought it. Then we cut brush - mostly willow, snowbrush (
ceanothus), wild rose, cottonwood - piled that along with the slash we created cutting firewood, and burned that.
Over 3 days, we burned conservatively 3 cords of waste. That's the energy equivalent of about $2000 worth of gasoline at $2.70 per gallon (which is what I paid today). The 8 cents it cost us to produce that energy was about 1/2 cup of gas for the chainsaw. $2000 worth of energy up in smoke. I'd estimate it took about 1 acre of land in a dry climate to produce that waste, plus all of the firewood we used to heat our house last winter. Now think about how many acres of National Forest alone the government owns.
A long time ago I read someone's estimate that there's enough forest debris (and to be clear, we're talking debris here - fallen trees, branches, brush, logging slash, etc, NOT standing trees) to meet a substantial portion of the nation's energy needs. I don't have a link or an exact number, but you can get a feeling from the energy we extracted from one acre of poor land. It's also not a completely original idea - Sweden seems to be considering something similar.
But there must be a catch, right? Actually, several. We don't burn this stuff in our woodstove because stumps, 15 foot tall willows or 8 foot tall snowbrush, or 6 foot long branches won't fit. There's no efficient way to process that stuff to heat a home with it. Another catch is that it's virtually impossible to automate collection of this stuff - it takes a lot of physical labor (trust me, I ache). Lastly, cars haven't run on wood since the Stanley Steamer, if even then.
But what you can do with all of that junk is generate electricity. 12.5 pounds of dry wood/wood fiber is equivalent to about 9 pounds of coal, and we transport coal to coal-fired generating plants every day. Other than front end considerations involved with handling and burning wood instead of coal, there's no difference, except that wood burns a lot cleaner (no sulfur, for example). Lumber mills, paper mills and plywood factories already do on-site electricity co-generation with their waste.
Where do you get the labor to collect all of this junk? I'd suggest it would a lot easier to get 150,000 18-21 year olds to spend a summer in the woods than a tour of duty in Iraq, and quite a bit cheaper too, but there are others who would also consider this kind of work. Moreover, the work is relatively unskilled and considerably safer than coal mining or oil-field work.
There are transportation costs. The energy density by weight of wood (BTUs or kilowatts per pound) is somewhere around 2/3s that of coal and about half that of gasoline. However the transport distances are likely to be considerably shorter, especially in the case of Middle Eastern oil, but even for coal if the generating plants are close to the resource. The transportation costs are likely to be on a par with something like ethanol, but without the energy inputs for things like fertilizer. Like ethanol from biomass, this is a renewable resource - depressingly, I'll be cutting the same willows and snowbrush in a few years, because they grow right back.
What about the environmental impact? After all, burning wood, like any other fossil fuel, produces CO2. The fact is, most of this stuff (in the west anyway) will burn sooner or later anyway, and release that CO2 into the atmosphere. The high fuel loads in forests (fuel load is the amount of combustible material per acre) are what cause the severe fires we have in the west every year - pondorosa pine ecosystems (like ours, and a lot of the west) are meant to burn periodically, but can't survive the fuel loads that currently exist. The cleanup we did this weekend was for fire safety reasons, not aesthetics (snowbrush is beautiful, smells great when it blooms, and burns like hell because of the oils in the leaves that make an evergreen species - we have acres of it because of the loss of canopy from logging).
We're currently working on a fire safety plan for our area. It will almost certainly involve controlled burns, piling debris and burning it - both of which release CO2 - or at best, transporting it to a central location and chipping it. Tax dollars will pay for a lot of that - one of the few good things about "Healthy Forests" - but we'll produce all of the pollution with none of the energy recovery.
Obviously, this isn't completely free energy since there are costs for recovery, processing and transportation, plus the cost of generating plants, but it's about as close to free as you can get, has comparitively low environmental impact, actually improves forests and doesn't require invading other countries (although Canada has a lot of forests too ...).