Drive on Sunshine

Austin is consistently ranked as one of the top 10 electric vehicle (EV) friendly cities in America. Many of our home clients have EVs, and at Native, we are now installing EV circuits into all of the new homes that we build. Why are so many of your neighbors adopting EVs? The price of EVs has come down and there are now several affordable options available below $25,000. But it’s not just the sticker price that is attractive. The cost of ownership is also lower since fuel costs shift from expensive gasoline to less expensive electricity.

But there is another reason to shift to EV. Many EV owners want to lower their environmental impact and desire a truly zero emissions vehicle. While there is no tailpipe on an electric motor, if our EV is to be truly considered zero emissions, we need to account for how the energy stored in the batteries is generated.

When we charge our EV from the grid, we don’t necessarily know how that power is being generated. ERCOT’s annual report reveals that in 2014 in Texas, 77% of electricity was generated from fossil fuels, 12% from nuclear, and only 11% from renewable sources. Austin Energy has a better record, procuring over 20% of its electricity from renewable sources. Even so, the vast majority of power in your batteries is most likely generated from fossil fuels! So, the best way to ensure that your EV is truly a zero emission vehicle is to charge your batteries with clean electricity that you generate yourself! The best way to accomplish this is to drive on sunshine by installing a solar array on your house, carport, or utilizing a ground-mount system.

 We sat down with our own Cathy Redson to crunch the financial numbers on the costs of running an electric vehicle on sunshine versus gasoline.

Native Solar: If a customer wants to Drive on Sunshine how much does that cost? How do we begin to figure out these economics?

Cathy: For the purpose of this discussion, let’s use the battery specs of a Nissan Leaf. It has a 24 kWh battery bank and a driving range of 84 miles. We will compare that to a gasoline car that gets 24mpg, which is about the national average fuel economy for new vehicles. Let’s assume that gasoline will average $2.40/gallon and that you drive 10,000 miles per year.

Gasoline car:
$2.40 gallon / 24 mpg = $0.10/mile
Annual fuel cost = 10,000 miles * $0.10/mile = $1000

The annual fuel cost is $1000 for a typical new car. Now we need to figure out how much energy (kwh) that an EV requires for the same amount of driving. Then we will size a solar array that will produce that same amount of energy. Finally, we price it out and determine how many years of gasoline savings it will take to recoup the solar investment.

Electric car:
24 kWh / 84 mile range = 0.29 kWh / mile
Annual energy needed = 0.29 kwh/mile * 10,000 miles = 2900 kwh

We need our solar system to generate 2900 kwh annually. Using Austin climate data, we calculate that a 2.0 kw system will generate that amount of energy. Looking at the net price of a solar array after an Austin Energy rebate and the federal tax credit, expect to pay about $3000.

Doing a simple payback analysis, $3000 solar cost / $1000 annual gas savings = 3 year payback!

There is tremendous value to converting your fuel source from gasoline to solar energy. Get a solar array and start driving on sunshine today. Take advantage of credits and rebates while they last and turn your EV into a true zero emissions vehicle.

Ask us how you can get started!