Nature
PUBLISHED
A newly announced solar powered carport offers drivers of electric cars and plug in hybrids a way to avoid the greenhouse gas emissions from charging off largely fossil-fuel powered grids.
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The iSolar carport, with roof made entirely of solar panels has been announced to coincide with the launch of BMW's i8 plug-in hybrid vehicle in Los Angeles. Southern California looks a particularly promising market for the iSolar. With no ice and snow to protect cars from most houses have dispensed with garages, but shade is still important, as the bright sunlight can make cars unpleasantly hot, and fade interiors over time.
By using solar panels to make up the roof, rather than adding them on top, BMW have kept the carport light enough that the support structure can be made of bamboo, further burnishing the iSolar's environmental credentials. When the car is in use, or fully charged, electricity from the panels is sent into the house.
BMW are very proud of the carport's aesthetics, saying their designers were focused “firmly on the harmonious interplay between vehicle design and architecture.” As a result, “The glass-on-glass solar modules of the carport are supported by exclusively designed bamboo and carbon elements that authentically reflect the hallmark lines and surface sculpting of the BMW i automobiles,” their media release states.
A few problems remain however. For a start, the panels sit flat, rather than being tilted towards the sun. This presumably makes them easier to install, but panels tilted south (or north in the southern hemisphere) will produce more power. The further one goes from the equator the more important this becomes, but even at LA's 34° North flat panels are missing out on a useful chunk of what they could be producing, particularly in winter when it will be hardest to charge the car. Tilting panels west, on the other hand, reduces the power still further but means more is produced at times when the demand is greater.
The i8 can only run for 37km when fully charged before it needs to switch over to using petrol, so even when their vehicle is charged entirely off solar few users will go close to fully carbon-neutral driving.
A perhaps more substantial problem is that, while BMW is using the idea to burnish their reputation as environmentally friendly, the iSolar carport is not actually for sale at the moment, and there is no sign when it will be.
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