When you buy an electric vehicle (EV), you get a big battery. The Nissan Leaf comes with a 24 kWh battery; the Tesla Model S sports one with 54 kWh capacity.
In a previous post, I talked about how situational intelligence helps EV owners stay within range of a charging station while they are out driving. But what about when your EV is parked at home—can situational intelligence help you get more value from your big, mobile battery?
First, it’s useful to understand how the capacity of a car battery compares to the power usage of a regular household.
An average US household uses approximately 900 kWh per month, according to the Energy Information Agency. Opower says that the bottom 90 percent of the economic strata use about 600 kWh per month. So, at 20-30 kWh per day for most households, and battery capacity of 24-54 kWh for most EVs, it’s conceivable for your fully-charged car to power your house throughout an entire day. (Of course, if you did that, you’re probably not driving anywhere that day.)
One way an EV battery is useful at home is demand response. In times of high grid demand, utilities could instruct houses to draw power from the EV battery instead of the grid, to reduce the need for additional, expensive peak generation. Demand response events range in time from a few minutes to a few hours, so demand response doesn’t need to put a crimp on EV range.
Another way an EV battery is useful at home is energy storage. At times of high grid supply, either at night when usage is low or on sunny days full of residential solar power, the EV battery can store excess energy and help keep the grid in balance.
Situational intelligence makes EV batteries more useful while parked by correlating, forecasting, analyzing, and visualizing multiple data sources such as
- EV location and battery capacity
- Grid energy supply and demand
- Renewable energy supply and demand
- EV owner’s demand response and car charging preferences
- EV owner’s home energy usage patterns
Understanding all these variables in real time across a city’s grid enables a more affordable and reliable power supply without inconveniencing EV drivers. With the right power prices and incentives, this can be added incentive for making your next car an EV.