Solar homes and EVs

Use the Sun’s Energy to Power Your Home and Electric Vehicle (EV)

September 5, 2018

By John Parry and John Matheny —

Solar homes and EVs are a perfect combination to reduce your carbon footprint and reduce your energy bill. A solar electric system powers your house with clean energy and charges your EV, with all excess energy going back into the grid. With a Time Of Use (TOU) metering rate, your cost of energy can be as low as 13 cents per kilowatt-hour during the night, and as high as 44 cents during the afternoon. This means solar customers can “buy low and sell high” for energy needs, and save money instead of spending on expensive electricity rates.

Cost Comparison: EVs vs Gas-fueled Vehicles
Efficiency for EVs is calculated by miles per kilowatt-hour (kWh) and for internal combustion vehicles by miles per gallon (MPG). Most EVs on the market today get about 4 miles per kWh. On the utility’s EV rate plan the cost per mile can be as low as 3.25 cents – even without solar.

On average, gas powered cars get about 25 miles per gallon. At current prices (about $3.50/ per gallon) that’s roughly 14 cents per mile. Hybrids, operating at twice the average efficiency, may be as low as 7 cents per mile. So, even the most efficient gas vehicles cost twice as much to fuel as EVs.

Driving an EV powered by your home’s solar electric system offers the greatest benefit because the average cost per kWh over the system’s estimated lifetime is about 8 cents. At 4 miles per kWh, you pay 2 cents per mile for a solar powered EV, only 14% of the cost per mile of a gas-powered vehicle.

Another benefit of “fueling” an EV via a solar electric system is the fixed cost of solar-produced electricity that won’t fluctuate over time. Electric rates have been increasing at a rate of 3.5% per year, so installing solar saves you money now and stabilize costs for years to come.

EVs Contribute to a Cleaner Environment
Our environment benefits when the electricity to power an EV comes from a clean source. If the electricity used to power an EV is from a coal-fired or other “dirty” energy source, the benefit is questionable. Fortunately, in California, nearly half the mixture of generation sources comes from non-carbon producing fuels, and none from coal. Many Community Choice Aggregation (CCA) districts offer 100% carbon free energy, such as Sonoma Clean Power Evergreen option and Marin Clean Energy’s Deep Green option.

Consider this: Electric motors are about 90% efficient compared to gas engines with only about 20% efficiency. Even using standard power from the grid, an EV produces just 1/6th of the carbon of gas engines. For more information, see these links:
Electric Car Myth Buster
The U.S. Energy Information Administration FAQ page
In California, vehicle emissions are the main pollution source. One of the greatest benefits of driving an EV is reducing local emissions, thus improving air and water quality. By switching to an EV you can contribute to a cleaner, healthier planet.

Solar Works Installs EV Charging Systems
Most EV owners opt to install a 240-volt Level 2 charger that requires as little as 4 hours to fully recharge the batteries. Solar Works recommends the most cost effective option: Installing the charger at the same time as the solar electric system. However, if you’re not yet ready to buy an EV, we can install an EV-ready outlet when we install your solar electric system.

See these Solar Works blog posts for more about the financial benefits of installing solar:

The High Cost of Delaying a Solar Installation
Local Financing Options for Affordable Solar

Contact Solar Works for clean, affordable, secure energy to power your home and EV
Phone (707) 829-8282