Green Mountain Power will break ground this spring on a cutting-edge utility microgrid in Panton, pioneering a new way to keep the power on for residents, farms and municipal buildings in the town center during power outages, GMP said this week. A microgrid is essentially a smaller grid that can operate independently, disconnecting from the larger grid during outages.

The microgrid will serve 50 homes, with expansion possible to about 900 homes.

The micro-grid would leverage GMP’s existing 4.9-megawatt solar facility with utility-scale batteries already up and running in the town. GMP is believed to be the first utility in the country to island a distribution circuit using inverter-based sources with no reliance on fossil fuel generation backup.

In the event of storm damage or a prolonged grid outage, the Panton microgrid will enable backup power from the batteries and solar panels to flow to a network of customers served by the traditional grid. The concept is called “islanding,” and it creates backup power that can work independently from the larger electric system when needed. In Panton, the tracker solar panels follow the sun, and can stretch the battery backup power for days, if necessary.

This will keep power on during outages for about 50 customers in Panton to start, with the planned possible expansion of the coverage area to include another 900 customers on that circuit. The batteries are also used to lower costs for all GMP customers during peak energy times.

Resiliency zones like the one created by Panton’s microgrid are a core feature of the GMP Climate Plan – a package of infrastructure initiatives approved by Vermont’s Public Utility Commission (PUC) last year to make communities even more resistant to outages and help ensure they can recover more quickly if outages occur.

The PUC approved the microgrid phase of the Panton project in the fall of 2020. GMP’s solar and energy storage facility in Panton first came online in 2019. The microgrid is expected to be fully constructed and working for customers by the end of June.

This year, GMP will be working with three additional towns that are among those most affected by outages due to severe weather, to create resiliency zones.  Using outage data, GMP outreach is underway to determine interest from possible towns to join the program. GMP plans to build on this work, adding more resiliency zones in more towns every year.

GMP also continues to deploy batteries in customers’ homes and businesses. Today there are about 3,000 home battery systems that provide power to customers during outages, and save millions for all customers by driving down cost and carbon emissions on peak energy days.