Electric vehicles are great: they’re affordable, great for the environment and low maintenance. And where electric rates are low — or if you have rooftop solar power — EVs are cheaper to drive per mile than gas-powered cars. But you have to think about how you will charge your EV: there are only a few thousand public charging locations in the U.S. — compared to 100,000 gas stations.

When you buy an EV it comes with a 120 volt charger that you can plug into just about any outlet. These 120 volt chargers are convenient, but can take awhile to completely charge your battery — about 12 hours for a Chevy Volt, 17 hours for a Nissan Leaf and 59 hours for a Tesla. So if you drive a lot you will definitely need a higher capacity charger, either at home or at work.

There are three choices for EV chargers: Level 1 chargers (120 volts), Level 2 chargers (240 volts) and Level 3 chargers (480 volts). Level 1 chargers are cheap and work just about everywhere, whereas Level 3 chargers are fast, but expensive and only work on certain EVs. Level 2 chargers are probably your best bet for home charging, but generally still require an electrician (and possibly utility permission) to install. Please Listen Up to this week’s Energy Show for the limitations and practical advice about charging up your electric vehicle.