Can a National Demand Response Event Fill in the Solar Gap for Monday’s Eclipse?

Credit: NASA

In fact, they probably won’t be aware that nearly 9 GW of solar power is expected to be lost due to the 82-minute eclipse.

But grid operators, utilities and demand response providers like Nest, well aware of the important role of solar energy in our power system, are gearing up to take action to fill in the lost electricity expected.

On Monday, in ERCOT’s territory, the eclipse is expected to affect about 600 MW of solar output, and in PJM’s North Carolina territory, about 2.5 GW of solar energy will be dimmed, said Scott Smith, Deloitte’s U.S. Power and Utilities Leader.

“Monday’s highly anticipated solar eclipse has been on the minds of grid operators and utilities for about a year now,” Smith said.

Nest has been anticipating the event with a plan to stage a first-of-its-kind national demand response event to try to fill in some of the gap. The event is an experiment that aims to uncover how homeowners respond to a simpler-than-usual and nationwide call for demand response, said Will Greene, product management executive at Nest.

Other load managing technologies — like microgrids and energy storage — are still too few to play any national role during the eclipse. That’s likely to change, however, for future solar events as they scale up on the grid. Monday’s Nest experiment could prove informative for these technologies, since they participate in demand response.

Voluntary national demand response

Nest began gearing up for the event about a week ago, letting customers with Nest thermostats know about it through a monthly home report. Beginning Saturday, Nest will begin sending messages on Nest thermostats, asking people to participate by clicking “accept” or “decline” on the Nest app.

Nest is aiming to reduce usage by 1 kW per thermostat in the hotter areas of the country, during mid-day hours, he said.

This is different than typical residential demand response programs, which often involve a fair amount of paperwork and wait times from utilities, Greene noted. Generally, homeowners have to sign up to participate in demand response programs, may need special equipment and education, and often wait for months before they’re accepted or can begin participating.

“There’s a lot of friction that is preventing people from doing demand response,” Greene said. “This time we’re making it as easy as a click of button to participate. We are just testing out the notion that if it’s as simple as the click of a button and if we use consumer-friendly language, will we get more buy in?”

Nest is reaching out to a few million customers who use air conditioning and are not now participating in a demand response program with a utility, he said. The company hopes that 1 million people will participate. Nest will raise the thermostat temperature limits no more than three degrees for the event.

Generally, utilities and other companies offer monetary rewards for participating in such events. In this case, the reward for homeowners is taking part in an unusual experiment on this important day, he said.

Meanwhile, grid operators are counting on hydropower and natural gas to help fill the gap in states that are expected to experience the greatest loss in solar, California and North Carolina, said Smith.

“Energy storage is not included as a component of California’s grid protection plan for Monday’s eclipse, though if the market grows as it is supposed to, then we can expect to see it included as part of the strategy for the next solar eclipse in 2024,” he said. The energy storage market is expected to grow by a factor of 12, hitting about 2.6 GW by 2022, he noted.

Grid modernization in action

Grid modernization efforts are expected to help fill the solar gap, as well, said Smith. Last year, investor-owned utilities spent $53 billion on grid modernization, he said.

CAISO is a leader in managing renewable energy resources through grid modernization, Smith said. “As a result, they have a clear understanding of what needs to be done to maintain reliability going into this eclipse.” He added that the eclipse will be more sudden and dramatic than extreme weather events that cause solar and wind projects to ramp down.

As a result of modernization efforts, grid operators can take advantage of improved forecasting abilities and access to dispatchable centralized and decentralized resources. In the future, they’ll be able to use grid-tied energy storage, he added.

Monday we’ll watch how demand response performs in this historic event, and get a feel for what role other strategies — including microgrids and energy storage — may play during such critical and historic moments in time.

Will a national demand response effort make a difference during the solar eclipse? Post your thoughts on our LinkedIn group, Distributed Energy Resources.