Electric vehicle owners generally cite four main reasons for purchasing their vehicles:1. Reduced fuel costs
2. HOV lane access
3. Reduced environmental impact
4. Energy independence
Each person will prioritize these motivations based on their own goals. As such, we encourage anyone interested in driving gas-free to do their research on battery capacity, charger types, local power sources, and utility rates to ensure maximum return. While far from comprehensive, here are a few eye-opening facts to help you get you started.
The easiest of the four motivations to achieve is the HOV lane access. In Arizona, cars with single-occupant HOV lane access are designated by a cloud plate. Cloud plates are still available to any fully electric EV. But, to truly realize the other three benefits—economic, environmental and energy independence—you must first understand the energy sources and cost structures of your local electricity grid. From there you can make informed decisions about where and when to charge up.
Like anything related to “the grid," there are many complex variables that can impact the cost of recharging your vehicle. And environmental impact of any electric vehicle is only as clean as the energy from which you’re charging. Before you start driving gas-free, consider these four facts.
1. Utility electricity isn’t that clean
According to the U.S. Energy Information Administration, in Arizona the majority of our power is generated from fossil-fuel plants, including a network of natural gas-powered “peaking stations.” Next up is the the Palo Verde Nuclear Station, the largest in the U.S.. Only about 10% of Arizona's energy is from green sources, namely hydroelectric and solar. Unless you have a rooftop solar system, plugging your EV in at home simply shifts your carbon footprint from the gas pump to your wall outlet. Solar is the way to go if you live in Arizona and driving green is important to you.
2. Timing can dramatically impact cost
Where and when you charge your EV will have a dramatic impact on your monthly electricity bill. For example, a customer on the APS “Savers Choice” rate plan will pay about $.24 per kWh on-peak, while off-peak rates can be as low as $.03. So, a Tesla owner charging during super off-peak hours (10 am – 3 pm weekdays, November – April) will pay 1/8th the amount to fill their battery. This assumes, of course, that a full charge can be reached in the five hours before on-peak hours arrive. Knowing your charger’s capabilities and rate plan is the only way to ensure you’re getting the cheapest fill-up. Adding solar to your home is the only effective way to reduce, or eliminate, both your use of utility power and the cost of charging your car during daylight hours.
3. Demand pricing changes everything
With demand pricing, a larger percentage of your monthly bill is no longer based on total kWh used, but instead tied to the peak kilowatts you pull from the grid during a short timeframe (30 - 60 minutes). Charging an electric vehicle using a Level 2 charger on the SRP E-27 demand plan will add roughly 6 kW of demand (varies by manufacturer), or about 1.5x the demand of a large AC unit, to your cumulative monthly demand fees. To put that in context, an electric vehicle could easily contribute more than half of your total demand, resulting in a much higher monthly bill. To plan for a demand pricing future, train yourself now to only charge during off-peak hours. And if you must charge during on-peak hours, be sure that few, if any, large appliances are running at the same time.
4. Go solar and drive on sunshine
A rooftop solar system and integrated Level 2 EV charger is a great solution for those who must charge their electric vehicle during daylight hours when utility power is the most expensive. Plus, filling your “tank” with the power of the sun helps to reduce the negative environmental impact of utility power. It’s important to note that it takes electricity to make the batteries that your car uses. Most experts agree that the sunken environmental impact of manufacturing those batteries will take years to overcome, depending on how clean your local energy mix actually is. The more you charge with clean, renewable energy, the faster you’ll truly be driving green.