Why to Buy It
These battery-op machines use less electricity because solar panels power their batteries. Some units (like the one shown above, the only model available in the U.S.) feature detachable solar panels that can be mounted on a garage roof or elsewhere for continual charging.Keep in Mind
The solar panels need three days' worth of sunlight to fully charge the battery. As panel technology improves, though, charging times will shorten. An included backup plug-in charger does the same work in only 6 hours (but using it negates your energy savings, of course).
Sun Whisper 19-inch mower, about $695; Free Power Systems