When Navigant Research examined nine California microgrids that have a total of 21 MW of generating capacity, it found that the biggest value propositions were renewable energy integration, resiliency and bill savings. But it also found emerging benefits from incorporating charging infrastructure for electric vehicles.
“The point is that electric vehicles are growing rapidly and historically, they have been viewed as a problem by utilities,” says Peter Asmus, research director with Navigant Research, in an interview. “They can consume as much as energy as a house and utilities are concerned about reliability. While electric vehicles can be a problem, they can be part of the solution.”
To that end, electric vehicles are becoming an enabling technology for microgrids and virtual power plants. Within five years, Asmus says, the concept will have fully emerged. Unlike a microgrid that typically operates within a certain boundary, a virtual power plant is comprised of resources that can be scattered over a wider geography. In both cases, they provide value to the grid because they are a resource that can be called upon to deliver power.
The electric vehicle, in essence, is to be viewed as any other distributed resource such as an onsite diesel generator or a demand response program. If the main grid is down and the microgrid must step up, the internal battery can be used to supply backup power as well as to provide voltage support to prevent momentary lapses in electricity. Today, the concept is mostly embraced by aggregators — or fleet operators, which have vehicles parked all day and whose internal batteries can provide such services.
Consider the case of General Motors E-Motor Plant: Timber Energy Solutions partnered with OnStar and GM to develop a microgrid demonstration project for large commercial and industrial facilities. The objective here was to quantify how a microgrid comprised of various distributed energy resources that also involved a small fleet GM’s cars (Chevy Volts) could deliver benefits.
But the microgrids can use bi-directional inverters. That means that not only can they accept power from those electric cars but that they can provide power to them as well. In the case of GM, Asmus says that Navigant found that electric vehicle charging and “vehicle-to-grid integration” that provides power to the microgrid were considered “essential.”
“As we get more electric vehicles, that means grid reliability becomes more important,” says Asmus. “If there is an outage, that could affect transportation. Microgrids therefore become more important. We will need to get those electric vehicles charged up. So, a microgrid could have charging stations built into them.
“Customers like GM do not necessarily want a ‘microgrid’ specifically,” Asmus concludes. “They want a comprehensive energy supply agreement with onsite and offsite resources to meet their 100% renewable energy and/or greenhouse gas emissions reductions goals.”
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