Blogs, Energy Efficiency, Grid Scale

Data Shows Electric Vehicles Could Strain Electricity Grid

Real world data taken from a Texas community shows that the habits of electric vehicle owners could pose a challenge for electricity providers.  The data collected is part of an ongoing study being conducted by Pecan Street, Inc. a research group based in Austin.  Pecan Street is seeking to understand how people will really manage their electric vehicles in the wild and to test the assumptions that have been made about how, when, and how often people will recharge their EV batteries.

To do this the company installed instruments to track the way people use their electricity within a planned community in Austin called Mueller.  The Mueller community makes a perfect test lab to study such things because it is a planned community built around a renewable energy and sustainability ethos.   The community is built from the start to maximize sustainability and incorporate smart grid technology and energy management systems.  Not surprisingly it has one of the highest concentrations of electric vehicle owners in the world.  Specifically, the Chevy Volt seems to be the car of choice in Mueller, with a few Nissan Leafs sprinkled in.

The study shows that, absent any incentive to do otherwise, people will default to the behavior that’s easiest and most convenient for them.  That means when they come home from work in the evenings they plug their cars in so that they will be charged and ready to go for the next morning.  The problem is that everyone, more or less, does this at the same time.  This also happens to correspond to the timeslot that is already a peak electricity usage time of day.  In Texas this is when air conditioners are working hardest.  It’s also when people are turning on televisions, dishwashers, washing machines, etc…

All of this simultaneous demand for electricity taxes the grid’s ability to produce enough power all at once to meet demand.  Not only does this make it more difficult for electric companies to keep up, but it also makes electricity rates go up because providers have to bring more expensive electricity into the mix.

Electricity is at it’s cheapest just a few hours later around midnight but people aren’t waiting until midnight to plug in their cars.   One important thing to note about the Mueller usage data is that there is no time based pricing currently in place.  This means no incentive for consumers to change their behavior.  It’s possible that by pricing their electricity more in line with the actual wholesale price of electricity throughout the day people would shift their car charging to later in the evening when electricity rates might fall substantially.

The sample size for the study is quite small but so far the result have be in line with expectation about when people will charge their electric vehicles.  If electric vehicle usage continues to expand, it could case more growing pains for the Texas electricity grid that is already expected struggle with meeting peak demand for power over the next few years. 

See Also: Electric Vehicle Cost Comparison
See Also: Keep A Close Eye On Electricity Supply In Texas This Summer
See Also: TXU Rates: The Most Expensive in Texas?
See Also: Prepaid Electricity Plans