In high fire threat regions of California, long-distance distribution lines are often required to serve remote customers; these lines can bring risks of fire ignition and high maintenance costs. TRC is partnering with Pacific Gas & Electric Company (PG&E) to replace some of these distribution lines with remote grids, which can serve isolated customers while reducing wildfire risk and increasing cost-effectiveness and climate resiliency.
The Challenge: Traditional Pole-and-Wire Power Delivery
Throughout PG&E’s service area in California, isolated pockets of remote customers have been traditionally served via long electric distribution overhead lines that often traverse High Fire-Threat District (HFTD) areas – for example, in the Sierra Nevada foothills outside Yosemite National Park. In recent years, many customer sites in these remote areas have lost power during wildfires, when the power lines serving them are destroyed. These historical line routes are challenging to rebuild, due to rugged terrain. And they are costly to maintain, given the increased need for line hardening and vegetation management to mitigate fire risk.
The Solution: Remote Grid Hybrid Renewable Standalone Power Systems
With support from TRC, PG&E is working to replace many of these long distribution lines with a resilient, low-carbon local energy source: a hybrid renewable standalone power system, also called a remote grid. These hybrid systems use solar energy combined with battery energy storage and backup propane generation. These remote grids function as small power sources, serving isolated customers with clean energy; the solar-plus-storage system is sufficient for most of the year (with backup propane generation providing 10% to 15% supplemental power during the shortest days of winter).
TRC supports PG&E by providing owner’s engineering for these remote grid installations, including structural and civil engineering services and fire protection engineering services. We’re proud to support this ongoing effort to create a permanent, continuous, renewable power source that provides reliable service throughout the year for remote customers. PG&E expects these remote grids will benefit customers through:
- Avoided costs from distribution line maintenance, hardening, and vegetation management
- Reduced risk of wildfire ignition from distribution infrastructure
- Increased reliability of service during severe weather events and Public Safety Power Shutoff (PSPS) events
Based on the success of the initial remote grid projects, TRC will support PG&E in the further expansion of standalone power systems to support wildfire mitigation efforts in California. PG&E has identified hundreds of potential locations for remote grids and is targeting several new remote grid sites to be operational by the end of 2022.