Panelist: Extreme weather events among factors behind growing interest in microgrids

Pepco Holdings has about 270 MW of solar power between all three of its operating utilities

Internal modeling processes have helped Pepco Holdings (NYSE:POM) understand what customers want with respect to distributed generation, Robert Stewart, manager of Advanced Technology & New Business for Pepco Holdings, said on Feb. 9 during the 2015 ARPA-E Energy Innovation Summit held in Maryland.

Speaking on a session titled, “In search of a ‘secure’ energy future – Are distributed energy resources (DERs) more or less enabling,” Stewart discussed the company’s efforts with such resources.  

“We just recently completed our [advanced metering infrastructure (AMI)] deployment in Delaware, Maryland and the District [of Columbia], so that gives us about 1.4 million AMI meters there – that was part of an overall smart grid deployment,” he said.

The company also has about 270 MW of solar power between all three of its operating utilities – Potomac Electric Power Company(Pepco), Delmarva Power and Atlantic City Electric – and of that, about 236 MW is net energy metered solar.

“[W]e’ve been dealing with distributed generation for a considerable amount of time,” he added, noting that, as a result of that, the company has had to develop some internal modeling processes, which are helping the company understand what customers want and how to accommodate that.

He said that following the 2012 derecho, combined with Superstorm Sandy, “there’s a lot of interest in microgrids and for resiliency, so we’re doing the best that we can to being supportive and involved in that.”

Pepco Holdings is currently partnering with the U.S. Department of Energy (DOE) on developing a control system for a community microgrid within the company’s service territory that will be about 4 MW and include a hospital, fire station and grocery store.

Stewart also said that the company is working with the U.S. Department of Defense (DoD) on vehicle-to-grid storage, or a V2G energy conversion program where the company will be the aggregator into PJM Interconnection.

“We’re also involved in a couple of different pilots … for smart inverter technology evaluation for advanced modeling, for advanced grid interconnection like smart voltage regulators and other devices, so that we can figure out the different technology solutions to mitigate the impact of … high penetration of intermittent renewables,” he said.

Referencing the high voltage seen as a result of high penetration of solar in some areas, for instance, Stewart said, “[F]rom a distribution system operations perspective, it depends on where the distributed generation is injected into your distribution system as to whether it causes problems for you or not, so you have to do a lot of modeling.”

The grid has been described as the most complex machine created by man, but it is still a sum of its parts, he noted.

“[A]s more and more of those parts become outside the control of the utility, there is a perspective within the utility that you could start to see some perturbations, some issues with voltage stability and things going on, if you don’t have the ability to see it and tell it what to do,” he said. “[F]rom an electric distribution utility [standpoint], we want to be able to at least know what those microgrids are doing and have the ability from our system operators to move them up or down, to manage the output, either reactive power, real power, different things that can help mitigate some issues that we might see coming with the grid.”

Among the speakers on the panel, Erich Gunther, chairman and CTO, and co-founder of EnerNex, noted: “[D]istributed generation is at a point where it’s possible for us to integrate [it] into the power system – we have the technology, it’s much cheaper than it has been before – but what we’re missing is a framework in order to figure out what the new balance point is. How much is enough, how much is it going to cost us to enable the power system to support this distributed generation desire to maintain that always-on society?”

According to its website, EnerNex provides electric power research, engineering and consulting services to government, utilities, industry and private institutions.

Responding to a question on what are factors driving various states and regions of the country towards distributed energy resources, Gunther noted that it is key to acknowledge why one is interested in putting distributed generation in the first place – for instance, is it for resiliency purposes or for home owners to make themselves more comfortable about their energy security?

There are various “reasons why we use any technology and so before you go willy nilly putting a bunch of regulations and incentives out there, you probably should get an idea of what the heck the problem is you’re trying to solve, or at least be aware of the range of those problems, and I think we’re seeing that in some of these proceedings,” such as New York’s “Reforming the Energy Vision (REV)” proceeding, he said.

“[O]nce we understand that, we can start mapping that technology and going from there,” he added.

Also key to understand is one’s tolerance for an outage, Stewart added, noting that different customers have different tolerances for how long an outage lasts.

“That’s going to determine the kind of solution that may be viable for you,” he said.

In Maryland, through work involving a resiliency task force effort, Pepco identified two types of microgrid opportunities, he said.

One, referred to as strategic, is a permanent installation of generation and storage to manage a “24/7” microgrid, while the other, referred to as tactical, involves identifying a community area, pre-plan the load pockets and being able to “roll generation in if we needed to.”

That is a lower cost way for a community to ensure the creation of a microgrid in the event of a hurricane, for example, he said, adding, “there isn’t just one microgrid solution out there.”

Responding to a question on whether distributed energy resources, for instance, pose greater challenges regarding cyber security, Stewart said, among other things: “[I]t’s something that we all have to stay on top of. I don’t know that the DER or microgrids create a bigger problem, I think we just need to apply the same scrutiny to those devices as we do to other electric generation equipment and critical infrastructure.”

About Corina Rivera-Linares 3286 Articles
Corina Rivera-Linares was TransmissionHub’s chief editor until August 2021, as well as part of the team that established TransmissionHub in 2011. Before joining TransmissionHub, Corina covered renewable energy and environmental issues, as well as transmission, generation, regulation, legislation and ISO/RTO matters at SNL Financial from 2005 to 2011. She has also covered such topics as health, politics, and education for weekly newspapers and national magazines.