Now that the Chevy Volt and Nissan Leaf are showing up around Southwest Florida, I am starting to hear interest from people that want to offset their increase in electricity consumption with solar energy. In fact, we increased the size of one customer’s solar electric system recently in anticipation of his Chevy Volt purchase. That’s no surprise – an electric car does use a substantial amount of electricity instead of liquid fuels.
For the Chevy Volt, each full charge gets you between 30 and 50 miles depending on driving style, and consumes 12.9 kilowatt-hours of electricity. That full charge equates to around $1.40 in utility electricity for customers in FPL’s Southwest Florida territory. Charging the electric car fully each day after consuming all of the usable battery capacity would increase your electricity bill by $42 per month.
How can you prepare for electric cars with solar for your home to deal with this increase in needed energy?
You will need have an electrical contractor look at your existing utility service and main load center (circuit breaker panel) to determine if an upgrade is required. Charging an electric vehicle uses a lot of power, and adding a dedicated circuit is required. Some older homes may require a utility service upgrade as well. This assessment can be done before or after you have your solar electric system installed, but it may be easier to do it all at once.
You will need to decide how many solar panels to install. If you want to offset the entire increase in anticipated electrical usage from fully charging a Chevy Volt once per day, you will need a solar electric system in the range of 3.5kW on your home. The Nissan Leaf is EPA rated at 34kWh per 100 miles, and can travel about 73 miles on a full charge. If you fully charged a Nissan Leaf battery once per day, it would cost around $82 per month and you would want a solar electric system around 7.0kW to offset the increase. Of course, you can choose to offset just a part of the electricity needed or install even more solar panels to further decrease your electric bill.
You can consider a solar electric system the “fuel” required for your new car. Essentially, you will be prepaying for your “fuel” and locking in the price for the next 25+ years. Another way to think about it is that solar is an “accessory” for your car. The only difference is that you leave it at home! However you think about solar energy systems for electric cars, the two products are made for each other!