Converting trash to energy
Here's one way to reduce landfill waste -- burn trash and turn it into energy.
Fri, May 08, 2009 at 12:29 PM
Q. What’s all this stuff in the news about people making energy out of trash? – Nancy, N.H.
A. There’s no getting around it: We’re a trashy bunch. Americans throw away just under five pounds of garbage per person per day – up from less than three pounds in 1960. Lucky for us, all that trash doesn’t have to go to, er, waste.
The most common “waste to energy” (or WtE) facilities produce power by burning garbage. Heat from burning trash makes steam; steam runs a turbine that powers a generator. A WtE facility operates like a coal plant, but has less of an environmental impact. Still, many environmentalists oppose incinerator WtE plants, citing the heavy metals, carcinogenic compounds and other byproducts that can enter air and water when the trash is burned. Plus, WtEs could lower the general population’s incentive to recycle, if they became too common. And then there’s the fact that WtE plants are expensive — even pricier than coal or nuclear facilities, believe it or not. And they’re not as efficient as coal: a pound of black gold produces four times as much energy as a pound of garbage.
But the main benefit of WtE incineration isn’t energy production — it’s waste reduction. Today, we’ve got more trash and less space than ever, so it’s no small thing that WtE incineration plants reduce garbage volume by 90 percent or more.
And newer, better WtE technologies are emerging. Some of them could even produce energy from waste without incineration, in zero environmental impact, closed loop systems. An added bonus: these new facilities are typically more efficient than WtE incineration plants. To check out a cool example of heat-intensive, closed-loop WtE technology, click here.
So haste makes waste, yes, but waste makes energy too. And like a fine wine, WtE technology is only going to continue improving with age.
Story by Alyssa Kagel. This article originally appeared in Plenty in August 2008.