The Briceburg remote microgrid deployment is a first for the California utility and is one of a number to come.
The hybrid renewable standalone power system, which was built and installed by rural energy solution provider BoxPower, is intended to permanently replace the overhead distribution powerlines that previously served a handful of customers in Briceburg, a community in the Sierra Nevada foothills outside Yosemite National Park.
The area is in a high fire threat area and the new remote microgrid reduces the risk of wildfires, as well as eliminating the need for maintenance on the distribution lines. Such an approach forms part of PG&E’s wildfire mitigation plan and is a first for the utility, but it has been adopted elsewhere.
In Western Australia, for example, remote communities, sometimes at the end of hundreds of kilometres of distribution lines, are receiving standalone power systems, both improving the quality of their supply and reducing theirs and the utility’s energy costs.
The Briceburg system uses solar combined with battery energy storage and backup propane generation.
The system provides up to 89% renewable energy annually, generated by a BoxPower SolarContainer, a pre-wired containerised solution with integrated solar array and battery storage, and an auxiliary ground-mounted solar array with a nominal capacity of 36.5kW DC.
The storage is a 27.2kW/68.4kWh lithium iron phosphate battery system, while the backup capability is provided by two integrated 35kW propane generators.
The approach has potential use in other areas as well. Throughout PG&E’s service area, isolated pockets of remote customers are served via long electric distribution lines that in many cases traverse through high fire risk areas.
“PG&E is eager to deliver the benefits of remote grids to our customers, and we intend to expand the use of stand-alone power systems as an alternative to certain existing distribution lines, providing enhanced reliability with a lower risk profile and at a lower total cost,” said Jason Glickman, PG&E’s Executive Vice President, Engineering, Planning and Strategy.
In the Briceburg fire of 2019, five customer sites lost power when the line serving them was destroyed. The historical line route is challenging to rebuild through the last 2km of rugged terrain. Since then, PG&E has provided temporary generation to meet the local power needs.
The customers receiving electric service from the Briceburg remote grid include two residences, a visitor centre and telecommunications and transportation facilities.
PG&E and BoxPower can monitor and control the system via satellite and cellular connectivity, with capabilities for remote performance management, safety diagnostics, alarms, reporting and automated refueling notifications.
PG&E intends to use the experience of the Briceburg system along with other initial projects to determine an appropriate expansion of remote grids using standalone power systems to support wildfire mitigation efforts.
Hundreds of potential locations for remote grids have been identified and PG&E is targeting up to 20 operational remote grid sites by the end of 2022.