How clean are plug-in vehicles? Well, despite the EPA rating that lists the efficiency of the 2011 Chevrolet Volt with a range from 37 miles per gallon to 93 mpge (equivalent) combined to 60 mpg "composite" and pegs the vehicle's greenhouse gas emissions at 84 grams per kilometer, the truth of the matter is that plug-ins are only as clean as the source of energy that's used to charge them (until the range-extending gas engine kicks in with, anyway).
Solar panels capture energy and generate electricity while emitting less overall pollutants than most other methods in use today and that's exactly why General Motors has chosen to install an 18.2 kW solar array at its Detroit-Hamtramck assembly plant – the Volt's production site. Twelve charging points are located under the overhead array allowing plug-in vehicles to be juiced up. Even when the sun refuses to shine, the array manages to capture three kWh of electricity and when the clouds lift away, up to six Volts can be charged simultaneously. Hop to jump to catch a video tour of the Detroit-Hamtramck solar charging station.
[Source: General Motors]