Flattening the "Duck Curve" - Why The Timing of EV Charging Matters

Image CC by NCDOT Communications

The 21^st century energy system will look drastically different than the energy system of the 20^th century. Consumers will be increasingly able to generate electricity locally through solar panels, and utilities will be faced with different patterns of energy usage.

Many experts have been referring to the new pattern of electricity consumption as a “duck curve”, with demand peaking at mid-morning and evening, but dropping substantially during the day when solar power generation kicks in. This leads to a less efficient grid as utilities must keep power-plants on standby for rapid response when consumption peaks in the late afternoon.

However, electric vehicles may be able to contribute to “flattening” the duck curve if the timing of EV charging is done correctly. One of the things to help facilitate the charging of EVs at more desirable times is to provide more opportunities to charge them during the day, or in the middle of “the duck’s belly”.

At the moment, most EV drivers tend to charge their cars at night while they sleep. This makes sense since it is most convenient to fully charge an EV when it is parked for an extended period of time. However, the contribution of millions of EVs charging around the same time will exacerbate the duck curve effect.

Instead, charging EVs during the day while at work would force utilities to generate more power during that time. Taken on a larger scale, charging EVs during the day would create a more consistent period of electricity generation thus avoiding a sudden, massive spike in energy production towards 8pm. It would flatten the duck curve and make for a more efficient energy system.

Of course it’s still early days for both the duck curve and the EV market. While the current pattern of energy consumption and EV charging presents no immediate crisis, it is important to consider how this pattern will evolve over time. With renewable energy and electric vehicles becoming increasingly prominent in the 21^st century, we will need to look carefully at how to maximize the efficiency of our energy system so we can accommodate the emerging wave of green technology.

Joseph Tohill is a freelance writer and online communications specialist for organizations in the sustainability sector. He has a B.A. in Interdisciplinary Studies from the University of British Columbia and spent most of his academic career studying sustainable urban development; namely the interdisciplinary relationship between built form and natural environment.