Hawaiian Electric, Puna Geothermal Venture reach new agreement to reduce cost, expand output (Docket No. 2019-0333)

Posted on Dec 11, 2020 in Key Dockets

Hawaiian Electric and Puna Geothermal Venture (PGV) have reached agreement on an amended contract that will significantly lower electric bills on Hawaii Island, reduce greenhouse gas emissions and expand the island’s renewable portfolio standard to nearly 70 percent. The amended power purchase agreement was filed with the Public Utilities Commission (PUC) on Dec. 31, 2019 for its review and approval.

PGV is a geothermal energy conversion plant bringing steam and hot liquid up through underground wells.  The hot liquid (brine) is not used for electricity at this time.  The steam is directed to a turbine generator that produces electricity.

The exhaust steam from this turbine is used to vaporize (heat) an organic working fluid, which drives a second turbine, generating additional electricity. The condensed steam from the organic fluid heat exchanger is re-injected into the ground through reinjection wells along with the brine. The electricity generated by PGV is sold to Hawaiian Electric and distributed to customers.

The PGV facility in Puna, which began operations in 1992, has been shut down since the eruption of the Kilauea Volcano in May 2018.

An added benefit of the new contract is the upgrade of the 38-megawatt geothermal facility to produce an additional 8 megawatts of firm, lower-cost renewable energy, further reducing bills and the use of fossil fuels to generate electricity.

View the docket proceedings (Docket No. 2019-0333)

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