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Green Mountain Power turning to solar plus storage to manage costs during peak demand

Source: EnergySage

Vermont is often at the forefront of transforming its electric power sector, whether that's as a nation leader in renewable energy, being home to the first U.S. city that's run entirely on renewable sources, or installing clean tech solutions on the nations agricultural land

This focus on forward-thinking energy solutions is why I wasn't surprised to come across this story on a Vermont utility that was investing in solar panels and battery storage on a utility-scale to assist in smoothing out the strain on generation services during peak demand. 

This project, which is the first of three that was approved by state energy regulators, will bring 4.5 MW of solar panels and a 2 MW battery online-- which will total 14.4 MW and 6 MW, respectively, by the completion of the third project. In full, this system would be capable of providing 24 MWh of energy over a 4 hour period of peak demand after having been charged during the day-- times of peak solar collection but lower demand from the grid. By shifting this 24 MWh of demand during early evening hours to be generated during early afternoon, such a solar plus storage project provides a layer of security over excess demand and ideally prevents the need to build out an additional amount of baseload generation to achieve the same goal.

Just 24 MWh over 4 hours, it's true, may be marginal in the grand scheme. But Vermont's history suggest that this project will simply be the first of many like it when it's found successful. And the numbers look good:

  • The solar system is expected to produce 8,000 MWh of renewable electricity per year
  • The power purchase agreement is good for 25 years
  • The complete project will cost $14.3 million, but will be able to deliver electrical output during peak demand at a desirable cost of 8 cents per kWh

Beyond that, Green Mountain Power touted the tangible benefits to customers:

Energy storage and discharge during targeted peak load can save customers money on transmission and capacity. Other benefits include frequency regulation services to earn revenue for customers when the batteries are not dispatching energy to the grid, providing opportunities for energy arbitrage in times of high prices, and possible “islanding” capability....Serious climatic events and changing weather patterns make improvements to system reliability and resiliency for customers even more important.

Do you buy into these type of energy management solutions? Have they succeeded or failed in other areas that might foreshadow how this program will go? What is your organization doing in the solar + storage place? Let's discuss and connect about it in the comments below!


Matt Chester's picture

Thank Matt for the Post!

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Bob Meinetz's picture
Bob Meinetz on February 5, 2019


Vermont is often at the forefront of transforming its electric power sector, whether that's as a nation leader in renewable energy, being home to the first U.S. city that's run entirely on renewable sources, or installing clean tech solutions on the nations agricultural land. 

Matt, about all I can agree with here is "Vermont is at the forefront of transforming its electric power sector." None of it has been for the better.

For forty years, Vermont had the cleanest electricity in the country, with as much as 73% generated GHG-free thanks to Vermont Yankee Nuclear Power Plant. Then, in the wake of Fukushima, Canadian natural gas giant GazMétro saw an opportunity. By making a significant contribution to the re-election of then-governor Pete Shumlin, a merger with Central Vermont Public Service was approved, handing control of Vermont's electricity to a foreign interest.

Shortly thereafter Vermont Yankee was shut own, and (not surprisingly) natural gas consumption skyrocketed. The contribution from solar at Vermont's latitude and climate remains insignificant; wind has been stymied by environmentalists who discovered wind turbines looked ugly sitting atop once-pristine ridgelines. And that bit about "the first U.S. city that's run entirely on renewable sources"? The renewable source is biomass, which (believe it or not) is not leaves and twigs gathered from the forest floor. It's the result of clear-cutting Vermont forests of their old-growth timber, grinding it into wood pellets, and burning them to boil water. Neither clean, nor sustainable.

At least one Vermonter has been paying attention: chemist and utility consultant Meredith Angwin.

Matt Chester's picture
Matt Chester on February 5, 2019

I definitely agree that closing Yankee Nuclear was short-sighted. A great example that can be held up to show the value of nuclear as a clean power source towards clean energy goals (with reason to phrase those mandates as clean energy rather than renewable energy)

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