Puna Geothermal Venture (PGV) has begun supplying electricity to the Hawaii Island grid, two and a half years after the eruption of the Kilauea volcano put it out of operation.

The delivery of electricity from the geothermal facility, one of the largest and most reliable renewable energy resources in the state, began on Nov. 5. Testing will take place over several weeks with production gradually increasing. Before the eruption, the plant produced 38 megawatts, representing about 15 percent of the island’s firm generation capacity.

The return of PGV increases Hawaiian Electric’s generation reserve margins, ensuring there is electricity available for periods of high demand when other generators are out of service for maintenance.

Resilience and reliability have also been enhanced by new transmission lines that connect the PGV facility to the grid. The new lines are attached to steel and wood poles that meet upgraded design and resilience standards. The cost of repairs was paid by PGV’s owner, Ormat Technologies, Inc., and its insurers, not utility customers.

With PGV back online, Hawaiian Electric can further reduce the use of fossil fuels to generate electricity. Before shutting down in May 2018, PGV helped Hawaii Island achieve the state’s highest renewable energy percentage, close to 60 percent. Without PGV in service, the island’s renewable percentage in 2019 was 35 percent.

PGV’s return to service will have little immediate impact on electric bills since oil prices have fallen significantly since its shutdown. The typical November bill for a residential customer on Hawaii Island using 500 kilowatt-hours is $163.74, down from $181.76 in November 2019.