Can microgrids help to bridge the infrastructure gap for the EV charging surge?

So what exactly is the problem? We can connect an EV charging system in every garage and commercial parking lot, correct? It’s not such a big deal, right? Well, actually, it is a big issue and should concern everyone in the facility space as the change in load profiles and electric use will create significant issues that must be addressed short term and long term. Let’s take a look at the home and commercial use case.

The residential use case

The facility (or home) has a specific utility service size. For a home, one is looking to install a level 2 (or single phase 208/240) EVC. A standard 10-kW EV charging system will require a 40 amp service at 208/240 VAC (10,000 watts/240 = 41 with a diversity factor ~ 40 amps). Most homes operate on a 200 amp service and, if they’re like mine, may not have the excess ampacity to add a dedicated electrical line for EVC. In older neighborhoods, 100 amp services are still a standard and this would exceed the available capacity, causing a safety hazard in the worst case. So how do we address this challenge?

In most cases a service upgrade will help to bridge the gap, especially if a 100 amp service is at the house. With a standard 200 amp service, the homeowner may be able to find enough breaker space to install a dedicated line but, if not, it will require an upgrade to a 400 amp service.

Can a microgrid help alleviate this concern? At the moment, it’s a challenge. Utilizing battery storage can possibly help in a residential setting and there are some solutions on the market today, however, none of them address the existing ampacity problem with the distribution system. Is a battery-enabled microgrid a solution in a residential setting? Storage is not a bidirectional solution that will alleviate the distribution system problem. Current efforts by several microgrid control providers are exploring how to provide single phase systems that alleviate the ampacity challenge. With the potential business case, we estimate a solution within the next few years in coordination with rooftop solar to provide a renewable option for homeowners while supporting the existing utility distribution infrastructure.

The commercial use case

Let’s take a closer look at commercial buildings, which are supplied by three phase power. Adding EVC to these facilities seems fairly straightforward, but not all is as it seems. We still have the ampacity issue even at three phase supply. Buildings were not designed for the extra loads EVC will require. The issue is that there is a need for level 2 as well as level 3 charging services, depending on the site. Level 3 is a three phase fast charge system requiring higher electric service, which directly impacts the utility service entrance. This is where a battery-enabled microgrid can be the stopgap solution. Utilizing a battery coupled with grid control to the various DERs will create a system that supports the existing grid and provides energy for EVC as well as the facility. A battery-enabled microgrid can alleviate the distribution system concerns while providing resilience.

An EVC game changer

Let’s talk about the game changer for EVC. What can we do to meet the EVC challenge? Add a battery-enabled microgrid with EVC and you maximize the ability to charge vehicles and keep the critical load operating. The solution is ready and commercially available to support the grid. Leveraging technology, we can deliver EVC solutions that meet the new EV reality while stretching the existing infrastructure.

The reality is the facility is short of available amps and the battery-enabled microgrid will provide the energy needed to charge the vehicles as well as keep the critical loads running.

Norm Campbell is manager of business development at Go Electric.