EV Charging: Friend or Foe?

Electric Vehicles are going to be a very big deal for energy systems right around the world. Even at their simplest they are pretty serious energy assets, with a relatively small EV like a Nissan Leaf still having a battery several times larger than a typical home Battery Energy Storage system (BESS).

Once you add vehicle-to-grid (V2G), at which point the EV isn’t just charging off the grid but potentially discharging (for financial gain) into it as well, things get complex pretty quickly.

How EVs will interact with existing networks and loads, as well as with other behind-the-meter DER assets like solar, controllable loads and stationary storage is something we’re starting to look at in earnest.

Here’s some high level analysis of the potential impact that the addition of EV charging may have on a commercial retail site, purely from the perspective of network costs. In this case the business is wanting to offer charging but isn’t sure of the impact on energy flows or costs.

The first graphic shows 7 days of simulated load profiles under BAU (blue trace) & then under a low & high EV charging scenario, with the corresponding 12-month network costs for each. The customer is on an AusNet Services CPD tariff.

The second graphic includes behind-the-meter solar & stationary storage for contrast.