Solar-electric Mowers & Tractors

Image Gallery This solar-electric tractor, converted by John Howe from an old Farmall Cub, pulls a disk harrow with ease. JOHN SNYDER

Imagine a lawn mower that whirs instead of roars. Imagine a tiller powered entirely by sunlight. Imagine a tractor that doesn’t spew exhaust. These aren’t idle dreams — such machines exist today. And every year, a few new electric and solar-electric implements reach the market. Meanwhile, adventurous inventors, far-thinking tinkerers and electric-vehicle enthusiasts do it themselves, using 21st century technology to convert existing mowers, tractors and other implements to solar-electric power. They’re handling chores and putting food on the table, even as oil wells are drying up.

Solar-electric implements offer sustainability and freedom from fossil fuels, and electric tools, mowers and tractors are cleaner and quieter than their gas-powered counterparts. That explains why they’re showing up on a growing number of farms, market gardens and lawns around the United States and Canada.

Several U.S. companies sell electric lawn mowers, some of them cordless and rechargeable. One sells a small walk-behind tractor and a lawn mower, both powered by solar panels, and is developing a solar-powered electric tractor. Another company plans to introduce electric lawn tractors in Europe later this year and make do-it-yourself conversion kits available in North America soon thereafter. Electric-powered tillers, garden carts and other implements also have appeared on the market in recent years.

Solar-powered Farming

Steve Heckeroth, a renewable-energy pioneer, off-the-grid homesteader in northern California and award-winning architect, says switching to clean, renewable solar-electric power is one of the best ways to solve our growing crises in energy and global warming. And he walks his talk — since 1993, he’s built about a dozen electric cars and converted six farm tractors to run on rechargeable batteries and electric motors, rather than conventional gas or diesel engines. When their solar panels are fully charged, his best tractors can run a loader all day, cultivate for about four hours or drive a rototiller for two hours. The batteries recharge in about three hours.

Some of his tractors carry their own power source: a canopy of solar panels suspended over the machine (see Image Gallery). “The canopy on those tractors generates less than a kilowatt,” he says, “but for planting and harvesting, that’s enough to run the tractor. This is where the electric tractor can really shine.” Heckeroth says electric motors have several big advantages over internal-combustion engines, especially for tractors. Gas engines rarely achieve 20 percent efficiency, but electric motors often approach 90 percent efficiency. Motors never waste fuel by idling; they simply stop. Even if the batteries charge from the conventional grid, an electric motor accounts for far less air pollution than a gas engine (studies show reductions of at least 50 percent). But the clearest advantage of electric vehicles is that they can be charged from nonpolluting, renewable sources, thereby reducing dependence on fossil fuels.