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Vermont’s Power Grid the Key to More Renewable Energy


by Heather Calderwood

Vermont’s power grid, the network that brings power from in-state generators, regional generators, and across borders, is considered to be one of the most technologically advanced grid systems in the country. Significant investments and innovations have been made within the past decade that have transformed Vermont’s power grid into a “smart grid.” For example, in 2006, Vermont Electric Power Corporation, Vermont’s electrical transmission company, upgraded its substations with four synchronous condensers — the first system upgrade of this magnitude in New England in 30 years. Building on this upgrade, utilities in the state followed suit by investing in their own upgrades, resulting in an improvement in overall system reliability. These upgrades include the widespread installation of smart meters, which communicate power activity with utilities. Additionally, supervisory control and data acquisition software (SCADA) was brought on-line to work in harmony with these technological improvements. These are just a few examples of the technological advances that make Vermont a national leader in power grid technology and an example of the potential of smart grids.

As advanced as Vermont’s grid infrastructure is, more investment is imperative to reach our renewable energy goals. The grid cannot handle any new projects coming online in certain areas of the state, areas where they would be well-sited. The success of the net-metering program created a swell in distributed-generation development, which then led to a paralysis from an engineering point of view, because the grid could not handle any new power sources in certain places. Furthermore, the 15-percent net-metering cap in development halted the emergence of any distributed generation. Well-sited projects are being turned away. Without an updated grid, we cannot build renewable energy generators at the rate and size we have seen in the recent past.

Smart inverters are a logical next step in improving Vermont’s smart grid. They are the least expensive upgrade we can make to increase the penetration of solar generation into the grid. Inverters are an important piece of the grid system that convert direct current into alternating current. Presently, most of Vermont’s inverters have two modes: full blast and off. Smart inverters would help support the grid in times of disturbance. For example, they will be able to shut off when the system gets too hot because of excess generation. Until upgrades and further deployment of this technology are made, the grid will continue to run into the same challenges we have seen it encounter over the past year.

However, increasing this smart grid technology presents numerous regulatory and economic questions for developers of distributed generation and for grid supervisors. Interconnection and unlimited access to the grid are both seen as rights by individual home-owners and companies. Restricting the output of solar or other renewable sites based on when the energy is directly needed could limit the bankability of solar and wind projects and run into various regulatory issues. Nevertheless, deploying more of this technology, either through legislative or regulatory mandates, is necessary to allow more solar and wind generation to come online, which is one way to meet our in-state renewable energy goals.

Heather Calderwood is an energy policy analyst and holds a Master’s Degree in Energy Regulation and Law from Vermont Law School.