WESTBOROUGH, Mass. — More than 150 people attended ISO-NE’s first-ever Grid Transformation Day last week to hear about the speed of the change overtaking the power industry — and the breadth of resources needed to accommodate it.
Here’s some of what we heard.
Dealing with Outdated Data
Stephen Rourke, ISO-NE vice president for system planning, said the industry is changing so fast that some of the RTO’s statistics for last month are already significantly misleading.
One example: The figure of 1,381 MW of battery storage in the interconnection queue as of April 1 is already out of date, with the number now topping 2,500 MW.
Information is still key, he said about the RTO’s response to growth of distributed energy resources.
“So every night at around 10 or 10:30, we get five-minute snapshot data from 10,000 different solar sites around the region,” Rourke said. “Thanks to working with the utilities and the states, we have actually mapped every single solar panel in New England to the town or city that it’s in.”
However, getting that data in real time would significantly increase costs, “so we have not gone down that path yet,” he said.
Steve Widergren, principal engineer at Pacific Northwest National Laboratory, said that our modern, data-driven society requires a much more flexible and resilient transmission system, which must transition to meet the challenges of changing demand characteristics, he said.
“We’re asking the grid to do a lot more than it was originally designed to do, which I think has been the mantra for electricity through its entire life,” he said. “We have already seen what extreme weather events are doing and can do, so the mission is how to mitigate the damage and recover quickly. The grid is increasingly a critical national asset.”
The policy environment is changing as “corporates and municipalities are demanding more clean energy, and this clean energy operates in a different way from traditional power plants, so that’s a challenge for the system,” said Janet Gail Besser, managing director of regulatory innovation at the Smart Electric Power Alliance.
She listed various legislative initiatives around the region, including a bill on solar siting in Rhode Island (House Bill 5789).
“As we see more of these resources, we see more of the challenges in siting even distributed energy resources, and that’s not going to go away,” Besser said.
Technical Challenges
Aidan Tuohy, principal project manager at the Electric Power Research Institute (EPRI), spoke of the challenges of integrating DER into grid operations, such as ramping to compensate for both short- and long-term intermittency of wind and solar.
In his native Ireland, for example, the grid operator is “buying 14 different kinds of ancillary services to deal with all this,” Tuohy said.
Hosting capacity — the volume of DERs that the distribution system can handle at a given time and place — is important from a bulk services perspective and comes up when trying to get distributed battery storage to provide some service that can’t actually be accessed because the system is starting to hit some limit, Tuohy said.
“EPRI has been exploring the use of technologies to better understand where and how much DERs you can put on your system so that you can then plan around that … and flag where upgrades are needed,” he said.
Barry Mather, manager for integrated devices and systems at the National Renewable Energy Laboratory, said grid operators have “a lot of tools in the toolbox” and that the large number of options is in itself a challenge.
In sharing NREL research on the Hawaii grid, Mather said it is “a very interesting system with lots of PV; mostly distributed, not transmission-scale,” which results in steady-state over-voltage issues.
What smart inverter function should actually be used?
“Obviously, frequency ride-through is a big deal on an island system such as in Maui, where you have relatively large frequency transience, just because the system is not very large,” Mather said. “But even [with] things like the volt/[volt-ampere reactive] settings [on inverters], how specific do you need to be?”
“Another important step in this planning matrix is to understand where you are going to go, because these DER assets, even though they’re small systems … are designed relative to a utility-scale lifetime, maybe 25 or 30 years,” Mather said.
The smart inverter setting you set today may not be the same setting that will be needed when DERs reach their ultimate penetration level, he said.
“The biggest game-changer is demand response,” said Debra Lew, senior technical director at GE Energy Consulting. “I can’t convey to you the importance of this … think of it as demand response on steroids. This is going to be way bigger than what you think of today because, first of all, we’re electrifying all these new loads,” from transportation to space heating to water heating and cooling.
“These loads are inherently flexible; we can extract a lot of flexibility out of them, so a significant amount of our demand in the future is going to be price-responsive or controllable,” Lew said. “This demand is going to compete directly with storage, and that’s something to think about as you make investments for the future.”
Lew said she participated in a meeting the previous week in which a Californian said their state currently had a half-million electric vehicles and plans for 7 million.
“We did a back-of-the-envelope for 7 million electric vehicles: 420 GWh of storage. That’s huge,” Lew said. “Even if you can access only a tiny bit of that, that’s a huge amount of storage.”
Utility Perspective
“Vermont is the Hawaii of the East, but our mountains don’t blow off their tops,” said Chris Root, COO of Vermont Electric Co.
Vermont is leading the way in New England in terms of overall renewable energy on its system, but because of the intermittent nature of wind and solar, its grid is increasingly weather-dependent as more renewables come on, Root said.
For example, he said the load in the middle of an overcast day is 2.5 times that of a sunny day, and that when snow covers a solar panel, its energy production drops to zero — which drew the comment that Hawaii probably had the edge in weather.
“I do believe storage is going to be critical in the future, because we have loads that change, we have generation that changes, and the only thing that’s going to be able to equate that is going to have to be storage,” Root said.
He said Vermont utility Green Mountain Power has installed 1,900 Tesla Power Walls and “can’t install them fast enough.” He noted the state has two utility-scale energy storage facilities of 4 MW and 1 MW — but he likes to remind people that storage is not an energy source.
“You have to put energy in; then you can take it out.
“Sometimes when policy gets way ahead of engineering, that can be a little scary,” Root said. “We’re still solving the problems that are happening today, so it gets a little scary when you’re trying to play catch-up from an engineering perspective.”
National Grid has seen its average solar interconnection request in Massachusetts triple in size over the last few years and double in Rhode Island, said Brian Gemmell, the company’s vice president for asset management and planning.
“For those that know the transmission system well, there’s a lot of ripple effect with getting all these megawatts. … We don’t have a lot of transmission in central and western Massachusetts and, indeed, some of the areas in Rhode Island,” Gemmell said. “We’re grappling with a dramatic uptick in [distributed generation].”
“It’s a given that we’re going to need innovation … but the biggest thing we’ll need is collaboration,” said Vandan Divatia, Eversource Energy’s director of ISO-NE policy and interconnections. “We have a role in every sector of the grid, from a customer-facing angle to grid-type investments, to supply, and the key thing is going to be collaborating with the right folks.”
Highlighting the ambitious clean energy policies and greenhouse gas reduction targets of various states in the region, Divatia said, “This may mean, based on the numbers you run … one scenario is you need to have every single new vehicle by 2030 to be electric.
“Massachusetts has shown great leadership in this area by enabling a make-ready program to deploy $45 million to get about 18,500 EVs,” and the region needs about 80,000 charging stations to help people overcome their range anxieties regarding EVs, Divatia said.
“Again, if we want to go from here to there, we’re going to need a lot more electric infrastructure,” he said.
— Michael Kuser