The Community Microgrid As A Virtual Power Plant

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The design for a community microgrid project that is forming in Warner, New Hampshire, seems rather prosaic at first glance. It is simple, with a few buildings, some solar panels, batteries, inverters, and all the regular gear. It seems an appropriately small start for a town with only 444 people in its center and a total population well below 3,000.

However, I should have known something was up with this design right away, if for no other reason than because one of the people involved was Roy Morrison, who is a visionary, proclaimed an “energy expert” in the pages of Forbes, and author of books on sustainability. He described a very modest design. “It will start with three buildings.”

“What kinds of buildings are they?” I asked.

“Residences, businesses. It really doesn’t matter.”

I stumbled mentally a little. “You mean you haven’t chosen them yet? Don’t they have to be selected carefully to be near each other?”

“No.”

Okay. Time to reset my thinking. “How do you wire them together?” I asked.

“You don’t. You use the grid.”

“But what if the grid is down?”

“Then they operate independently.”

“Wait a minute. Are you telling me that each building is its own microgrid?”

“Yes.”

“Then the community microgrid is made up of smaller microgrids?”

“Yes.”

“Why?”

“The community microgrid is as a virtual power plant.”

A gathering at the solar stage in downtown Warner, New Hampshire. Photo courtesy of Neil Nevins.

Roy Morrison suggested I speak with Pentti Aalto, who is widely recognized as an expert in energy and was heavily involved in the project. Where Morrison’s area of expertise is more inclined toward the economic and social, Aalto’s is more nuts-and-bolts engineering. Speaking with both, I got a clearer understanding of what was going on. It took longer than it should have, perhaps, but that was because my own preconceptions got in the way.

Warner’s community microgrid is to be a virtual power plant made up as an aggregation of smaller microgrids, which I will refer to as nanogrids for clarity. Each nanogrid is capable of operating independently. The nanogrids communicate with each other, and they are capable of buying and selling electricity on the grid, as they are aggregated into the community microgrid. In theory, they could support each other in a time of need, if they are wired together independently from the grid. But in the practical world, they could give each other ongoing support through their aggregation, as the grid operates normally.

The implications of this design took time to sink in. After writing my first article on it in Green Energy Times, I was still working through it in my mind.

Ideally, the community microgrid, as a virtual power plant would buy and sell power in real time. The people and organizations participating in it would benefit by taking advantage of lower rates. They might even get an income from the community microgrid. The nanogrids would also have grid security, because each is capable of separating from the grid and functioning on its own.

With sufficient penetration in the town, it would be possible that the nanogrids could go beyond supporting themselves, and those close by, in the event of grid failure. If they can be detached together from the grid, they could provide mutual support. In the end, they could possibly even keep power going to utility customers in the rest of the community who do not have their own nanogrids.

The utility working with the community microgrid would benefit by having its load smoothed out. The community microgrid, and its nanogrid components, could buy power when demand is low. This gives the utility an ability to dump unwanted power at times and could even prevent power prices from going into negative territory. On the other hand, when the grid power is in high demand, the utility can get power from the community microgrid and, through it, from the solar arrays and batteries of the nanogrids, reducing its peak costs.

Clearly, this idea can benefit everyone involved.

As I developed a better understanding of the potentials of the system I came to wonder who had come up with the idea. I asked Roy Morrison.

“I don’t really know,” he said. “We have been developing the idea for years. A lot of people have been involved, perhaps dozens of them.”

I called Pentti Aalto again to see if he could tell me more. He did not have a name of a single inventor, but the conversation went on to other matters. I mentioned the idea that for customers and the utility, this could be a win-win situation.

“It is more complicated than that,” he said. “We need to have a legal structure that supports the idea.”

“Why? I mean if the utility refuses to cooperate, the community microgrid could just walk away from it. It would be better for everyone if that does not happen, but what choice do they have?”

“Regulated utilities have problems you might not have thought about,” he said. “For example, some of them, if you gave them all the power they could use for free, would go broke fast. This could happen if the regulations require them to sell power at a rate that uses the wholesale price as a multiplier. Anything times zero is zero, and without income, they go broke.”

Pentti Aalto did provide me with his vision for the future of community microgrids. If they can support one another, then they can provide a network of support that would keep the electric system going even if the long-distance electric lines of the grid cease to function. Ultimately, they could power an entire state. This could be important in the event of long-term national grid failure, which both NASA and FERC have warned us could last for periods of over a year.

The Warner microgrid project has been getting interest and support from some major organizations. One is the Carsey Institute, which is active on issues of public policy. Another is Schneider Electric, which has a worldwide presence.

Though this project has been going forward more slowly than I would like, it is exciting and a lot of people are working on it. I feel like I have just begun to learn the implications of the design.