We've shown you how to convert your petrol mower to solar power, but if you have an electric mower (or just don't feel like ruining your petrol one), here's how to harness the power of the sun on your battery-powered lawn mower.
Since the mower's already electric in this case, it's not quite as intense as converting a gas-powered mower. All you need are some 2-12 volt solar panels, some rectifier diodes, some double stick tape, and miscellaneous nuts and bolts. As far as tools go, you'll need to do a bit of soldering and wire stripping, so make sure you have the necessary tools around for that. You'll also want a volt meter since you'll be working with electricity.
The purpose of the diodes is to create a check valve of sorts, between the solar panels and the battery — since when the sun is down, electricity will flow in the opposite direction, from the batteries to the panels (thus wasting the energy). Thus it's just a matter of creating a circuit between the batteries, panels and diodes. Then slap the panels on top of the mower and you'll have yourself a self-charging lawn cutter for those hot, sunny summer days. Hit the link for detailed instructions.
Solar Lawn Mower [Instructables]