Rooftop Solar and Electric Cars Can Be a Win/Win

Going solar at home or at your business can be an excellent investment, not only financially, but environmentally as well, and when combined with a smart grid and smart appliances, can further optimize our energy consumption.

But one element of daily life, transportation, doesn’t fit very well into a renewable energy world, at least when it comes to the majority of vehicles on the road today. Gasoline and diesel powered cars can continue to get more efficient and cleaner to operate, but the cost to operate them will still be dependent on the price of oil, and because we aren’t going to see home-scale refineries anytime soon, the fuel to run them will still need to come a fair distance (and only after going through a massive industrial conversion process to turn it into a usable fuel).

Riding a bicycle, or an electric bicycle, is one affordable low-carbon alternative, but there are many times in our lives when a bike just won’t cut it, such as when we need to go long distances, or when we need to carry someone besides our own self (or a big load of stuff), or when the weather is inclement. At times like these, a car makes a lot of sense, and if it’s the right car, it can also make a lot of sense as part of an overall renewable energy lifestyle, as in the case of an electric vehicle.

By owning an electric vehicle that fits with your lifestyle (such as one with an appropriate cost, range, and size), and coupling it with a home solar system, it’s possible to spend a little more upfront in order to save a lot down the road, in terms of reduced fuel costs and maintenance.

One strategy is to simply build a standalone solar charging system just for the vehicle, but considering that most electric car owners charge them at night, when the sun isn’t shining, a standalone solar charger would also need to include a battery bank large enough to charge the electric car, which usually isn’t financially practical for most people.

A far better strategy is to design the demands of electric car charging into the size of the home solar system from the get-go, so as to be able to take advantage of producing more power when the sun is shining, as well as the off-peak electric rates from the utility during the night. The additional power produced by the home solar system can offset the additional electrical demand from electric car charging, and will serve to ‘lock in’ the fuel rates for many years into the future.

Up until recently, both the cost of electric vehicles, and the limitations of battery pack size and capacity, as well as the time to charge them fully, has been somewhat of a damper on the solar home + electric car pairing, but that’s rapidly changing. Electric car technology, including batteries and charging systems, has been moving ahead by leaps and bounds, and retail prices are coming within range of the average consumer. When tax incentives for clean cars are applied to the bottom line, and the customers learn how much cheaper they are to operate over the life of the vehicle, electric cars become a lot more appealing.

Solar power for homes is also dropping in cost and complexity, and with Federal and state tax incentives available for cutting the costs of installation and ownership, going solar is no longer a fringe thing or just for those in the upper income brackets. Putting a solar system in that will accommodate the demands of an electric car can be a win/win situation for home and business owners for years to come.

According to an in-depth analysis over at Greentech Media, the economics of pairing home solar with an electric vehicle is fast becoming feasible for more people:

“Even though a PV system can be costly, the savings from driving on sunshine versus driving on fossils can easily make up for the initial cost in a few years’ time. In crunching the numbers for various models, I found that payback times for the PV4EV solution are generally around ten years — good but not great, at least from a purely economic perspective. However, as costs for solar continue to fall and gasoline costs continue to rise, the payback period will become shorter.”

Another post, over at EnergySage, states that the cheapest option for ownership – between a gas car, a hybrid car, and an electric car – is an electric car:

“Looking at the long-term, full cost of ownership numbers, the cheapest option is to power an electric car with solar panels. Surprising? Yes, at first – but combining solar panels with an electric car makes perfect sense. And, not only is it a great financial decision, but it also delivers significant environmental and social benefits as well. The electric car produces less carbon emissions vs. the traditional gas fueled car and the hybrid, whether it’s powered by solar or not. If it is powered by solar, it has the added benefit of also eliminating the carbon emissions associated with your utility’s electricity production.”

We recently covered an innovation from Honda, where their open source smart home design includes an electric vehicle as part of the overall ‘zero net energy’ goal, which may eventually be a ‘turnkey’ solution for both home and car ownership. Perhaps one day, we’ll see new homes paired with a smart home energy management system, a home solar electric array, a solar hot water system, and an electric car, all as part of a low-carbon and future-proof package.

Some car companies are already making the connection, as demonstrated by the recent announcement from Volkswagen about their newest electric vehicle, the e-Golf. VW has partnered with SunPower, in order to provide the opportunity for qualified U.S. e-Golf customers to have a home PV solar system installed, in order to save money (and energy) at home, while also powering their electric car.

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