New Ideas in Rural-Size Energy

The Innovate column I write for Sierra magazine has one shortcoming: The word-count is too small for me to convey the wealth of useful resources I’ve found. Over the last few months, I blogged about the five technologies included in the March/April issue, which focused on what’s known as “Appropriate Technology.” When it comes to energy, this is a fancy word for cheap, durable energy sources for poor communities living off the grid.

Thermoacoustic Engine. The thermoacoustic engine is a technology that has some serious explaining to do. Many sources of natural energy, such as wind or solar or wave power, are fairly easy to get your mind around. But what the heck makes a thermoacoustic engine run?  The short answer is waste heat, which our industrialized society (and even rural society) has plenty of.

Efficient Cookstoves: Waste heat in a poor, off-grid community comes from the cookstove that combusts wood, dung, or some other burnable to cook food for the family. There are millions such cookstoves in the world and most are ripe for serious design improvements. A few simple changes to a stove’s design can slash the amount of feed wood, keep children safer, eliminate soot in the hut (and wipe black carbon from the skies), and cook food faster.

Solar Refrigerator: Another head-scratcher. How is it possible that a refrigerator could get cold because it is out in the blazing sun? Students at Michigan State University figured out how, and are doing so with materials readily available in Guatemala.

Windbelt: The windbelt fills a void our wind portfolio: It produces small doses of power very close to where it’s needed and can operate in winds that are strong or weak. It does this without lopping off the heads for birds, and requires almost no maintenance.

Treadle Pump: When I saw my first video of the treadle pump, my first reaction was, “Of course!” A farmer who can’t afford diesel and isn’t on the electric grid could save hours every day with the help of this cardio machine made from steel or wood.  An hour or more on the treadle pump can replace hours of labor for farmers in Asia, Africa and Latin America, and at a price they can actually handle.