As more electric vehicles take to the highway, they pose a huge challenge for grid costs and reliability, but they also have something unique to contribute. As rolling energy storage units, EVs can mobilize on the go to support demand response strategies that reduce electricity use during peak use periods. Now the companies ChargePoint and Green Charge Networks have added a new twist to shave peak demand and the high cost that comes with it: integrating energy storage with EV charging stations.

EV charging with energy storage

Demand Response Basics

The old way to meet peak demand was to build new power plants — peaking plants — that can be revved up quickly when use spikes. That’s a mighty fine solution if you have plenty of dollars to throw around or no other alternative, but today there are at least two alternatives.

The first is to offer electricity customers a huge disincentive for using electricity during peak periods by jacking up rates; conversely, low rates during non-peak periods help nudge consumers in the right direction.

That method has been used for quite some time in a rather simple, clunky fashion. More recently, smart metering, smart grid technology, and wireless, mobile communication have enabled more sophisticated and efficient demand response systems.

The second method is to build energy storage facilities that tap into cheap rates, and make that low-cost electricity available during peak rate periods.

Energy Storage + Demand Response

The mobile demand response solution by itself is a win for individual EV owners with charging stations at home, since they can charge at night when rates are typically low. However, it doesn’t address the demand charge obstacle faced by public charging stations at businesses and other non-residential users. Demand charges are based on the highest 15 minutes of use during a billing cycle, and new EV charging stations can pump that peak number up significantly.

The EV charging station solution hit upon by ChargePoint and Green Charge Networks is fairly straightforward: integrate energy storage with EV charging.

The two companies have been running a demo project in Redwood City, California, consisting of five combined EV charging and energy storage stations at a municipal library and a parking garage.

The system is enabled by ChargePoint’s website and mobile app, through which drivers can easily locate EV charging stations and check their availability in real time.

Users can start to charge up by tapping their ChargePoint credit card at the station, using the mobile app, or calling a toll free number (printed conveniently on the station).

So far, the EV charging stations have been averaging 8 to 10 charges daily, which is considered heavy use. Without the integrated energy storage, that usage would have pushed consumption into peak territory multiple times per day (the companies counted a total of 80 peaks in May alone).

With storage, the peaks were shaved down. Based on the experience so far, the two companies estimate that Redwood City will save about $7,000 yearly just from the five existing locations.


EV Charging: Who’s Gonna Pay For All This?

As for the payback period for Redwood City, there is none. Green Charge has a “unique” financing model:

The Redwood City energy storage equipment and installation came at no cost to the City. Green Charge’s unique financing model provides a zero down cost solution. Green Charge Networks installs, owns and maintains all of the energy storage equipment.

Green Charge can offer this sweet of a deal because it pays itself back, by taking a slice of the customer’s energy savings. It’s an ideal solution for customers that don’t have the resources to administer their own systems, though some companies and agencies may see the benefit in installing their own systems and keeping all the bennies for themselves.

Onwards & Upwards For Workplace Charging

ChargePoint has been focusing on workplace EV charging and it has a powerful ally in that effort, the US Department of Energy.

Workplace EV charging features prominently in the Energy Department’s transportation electrification initiatives, and for good reason. Last year, the agency reported that the availability of workplace EV charging does promote EV usage.

In fact, workplace EV charging is becoming so popular, so quickly, that it risks adding yet another element of stress to the workplace — charge rage — as EV owners jockey for position at a limited number of EV charging stations.

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Image (screenshot) via Green Charge Networks.