4 Tips for Electric Vehicle Owners: Pause Before You Charge

Sabrina Lopez
October 31, 2016
3 min read

When surveyed*, electric vehicle owners cite four main reasons for purchasing their vehicles:

1. Reduced fuel costs
2. HOV lane access 
3. Reduced environmental impact
4. Energy independence

The easiest of the four to achieve is the HOV lane access. Still, to truly realize your electric vehicle's economic, environmental, and energy independence benefits, you need to understand your electricity grid's sources and cost structure and make informed decisions about where and when you plug in.

Like anything related to “the grid,” many complex variables can impact the cost of recharging your vehicle. We encourage anyone interested in driving gas-free to research battery capacity, different charger types, local power sources, and utility rate plans. While far from comprehensive, here are a few eye-opening facts to help you get you started:

1. Utility electricity isn’t that clean: In Arizona, 65% of our power is generated from fossil-fuel plants, including the coal-fired Navajo Generating Station (the 3rd-largest emitter of CO2 in the U.S.) and a network of natural gas-powered “peaking stations.” 25% is generated by the Palo Verde Nuclear Station, the largest in the U.S., while just 10% is from renewable sources, namely hydroelectric and solar. Unless you have a rooftop solar system, plugging your electric vehicle in at home shifts your carbon footprint from the gas pump to your wall outlet. To tap into the greenest utility power possible, consider charging your electric vehicle at night when natural gas peaking stations are shut down and hydroelectric makes up a larger percentage of the overall mix.

2. Timing can dramatically impact cost: Where and when you charge your electric vehicle can dramatically impact your monthly electricity bill. For example, for a customer on the APS “Time Advantage Super Peak” rate plan, on-peak summer rates can exceed $.45 per kWh, while off-peak rates can be as low as $.055. So, a Tesla Model X 70 owner could pay as much as $45 for a full charge during summer super-peak hours or as little as $5.50 off-peak. Adding solar to your home can reduce, or even eliminate, both your use of utility power and this cost/charge.

3. Demand pricing changes everything: Arizona utilities are the first in the U.S. to begin implementing demand-based pricing plans. With demand pricing, most of your monthly bill is no longer based on the total kWh used but instead tied to the peak kilowatts you pull from the grid during a short timeframe (usually 30 minutes). Charging an electric vehicle using a Level 2 charger on the SRP E-27 solar plan will add roughly 6 kW of demand (varies by manufacturer), or about 1.5x the demand of a large AC unit, to your monthly demand. To put that in context, an electric vehicle could easily contribute more than half of your total demand, resulting in high monthly demand fees. To plan for a demand pricing future, train yourself now to only charge during off-peak hours. If you must charge during on-peak hours, ensure that a few large appliances run simultaneously.

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 sun's power helps reduce the negative environmental impact of typical utility grid sources.

If you’re an electric vehicle owner and want to learn how to complete the clean energy circles by driving on sunshine, contact us today for a free, no-obligation quote.