The Complexities and Payoffs of Using Rooftop Solar Panels to Power Your Electric Vehicle.

Solar cells stand to place an increasingly prominent role in augmenting the practicality of electric cars.  In theory, the idea of using solar panels to charge electric cars seems a perfect combination. The sun is the planet’s greatest source of free energy and anyone with the capacity to harness it is at an advantage. The reality is of course more complicated:
Since most people are out during the day, the car will be away from the domestic panels used to charge them. At night, when the car will be parked unused, there is no sunlight with which to charge the car. However, this is a straightforward problem to work around. Instead of the solar panels linking directly to the car, they can instead be used to charge a battery bank when the car is in use. When the car is parked at home, the battery can then be used to recharge the car. SolarCity, one of the largest solar leasing companies, has recently begun offering such battery banks as a promotion to their customers –  ostensibly as a back up source of electricity in the event of a power outage – but likely also spying a gap in the market to be a provider of such equipment.
An alternative is that the panels are instead used to feed the electricity grid during the day, then when the car is plugged in at night the power is taken straight back from the grid. This often has an added monetary advantage to it, since through net-metering, electricity is typically charged more cheaply at night.  Then from a financial standpoint, you’re effectively getting out more than you put in.  Don’t plan on making big bucks on such an arrangement though – most utilities in the US will only allow you to generate credits to your bill instead of out-and-out revenue from net-metering.
Cities Play Catch Up

Despite the future of automotive efficiency lying very firmly in the solar panel/electric car combo, if everyone suddenly adopted the practice the situation would quickly become untenable. The electrical infrastructure of cities doesn’t currently possess the capacity to support an entire block’s worth of electric cars all charging at the same time, as charging an electric car can consume up to three times as much power as an average household.
For this reason it may be worth  considering making the investment before your neighbors do. If you wait too long, there could well be a fight over who has the right to utilize what power the local grid is able to muster. It will likely be some time before the necessary upgrades are made that will allow for the increased current that the vehicles will demand. The catch-22 is that upgrades are unlikely to be initiated until there has been enough uptake of electric vehicles to demand such improvements.
Another issue is if you park on the curb rather than in a garage, you’ll be a fair distance from where you can actually plug your car in to charge. Unless you want to trail a few dozen feet of power cables down the sidewalk, it will be difficult to maneuver your vehicle into a position where it can be charged.
However, things are slowly changing for the better. Many cities are introducing specialized parking spaces reserved for electric cars that also provide a socket to charge your vehicle while it’s parked. In the San Francisco Bay Area, which is home to the three largest suppliers of solar panel installations, there are areas with very high concentrations of such spaces, making electric cars not only viable, but also practical.
Looking to the Future

The attraction of electric cars is easy to see. With the world’s finances still in freefall and the price of gas increasing almost exponentially, the appeal of being able to power a car through renewable means becomes ever more appealing. As well as the financial payoff, the environmental benefit of electric vehicles is obvious and is only one of a number of reasons why you should seriously consider investing in what will likely become the vehicles of the future.

Anne-Marie Francis is a freelance writer from England who specialises in writing about the challenges faced by all vehicle users from car hire Lanzarote to energy saving issues such as solar power for private road users.

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