Geothermal resource permit application amendment for the Puna Geothermal Venture project

Abstract

The Puna Geothermal Venture (PGV) Project is a 25 MW (net) powerplant and associated geothermal well field proposed for the Puna District of the Island of Hawaii. The project, located in the Kapoho section of the Kilauea Lower East Rift Geothermal Resources Subzone, will sell the generated electricity to the Hawaii Electric Light Company (HELCO) for the Island of Hawaii. Since the proposed project is located within an area where the designated Geothermal Resources Subzone underlies an agricultural state land use district, the project requires a Geothermal Resource Permit from the County of Hawaii. The PGV Project is consistent with the stated objectives of providing energy self-sufficiency and diversifying Hawaii's economic base. The project will develop a new alternate energy source as well as provide additional information about the nature of the geothermal resource. These objectives are included in Hawaii's State Plan, the State Energy Functional Plan, and the County of Hawaii General Plan. On December 10, 1986, Thermal Power Company (TPC), as then operator of the Puna Geothermal Venture partnership, submitted anapplication to the Hawaii County Planning Department (HCPD) for a Geothermal Resource Permit (GRP) for the PGV Project. TPC also requested that the HCPD be the accepting agency for an Environmental Impact Statement (EIS) that TPC would voluntarily prepare and submit for the PGV Project. Although the HCPD determined that there were no clear requirements for preparation of an EIS, the HCPD agreed to act as accepting agency for the EIS and deferred acceptance of the PGV Project GRP application until after acceptance of the ElS. The Final ElS for the PGV Project was accepted on December 28, 1987, although the Hawaii County Planning Director again noted that the PGV Project did not require the filing of an ElS. However, further processing of the GRP application has not occurred because the entire interest inthe PGV partnership was purchased during the first half of 1988 by AMOR VI Corporation and AMOR VIII Corporation (AMOR Corporations), two wholly-owned subsidiaries of Ormat Energy Systems, Inc. of Sparks, Nevada. Since the purchase, PGV has reviewed the previous design of the PGV Project to determine if it remains entirely appropriate. As a result of this design review, PGV has decided to alter several aspects of the previously proposed PGV Project design to optimize production operations and further reduce the potential for environmental impacts. Principal among these proposed changes is the use in the power plant of back-pressure steam turbines, in combination with air-cooled binary cycle turbines, in place ofthe steam turbines and cooling towers proposed by TPC. This currently proposed power plant configuration applies a closed cycle for the geothermal fluid, thus essentially eliminating hydrogen sulfide emissions during normal operations and eliminating the need for cooling towers. Most other environmental impacts from this revised PGV Project will be very similar to those of the previously proposed PGV Project because the revised PGV Project will use the same geothermal resource, the same geothermal wellpads, and the same power plant location as the previously proposed PGV Project. This amendment to the GRP application has been prepared to replace, in its entirety, the GRP application submitted to the Hawaii County Planning Department in December, 1986. For clarity sake, Chapter 2 of this application is a summary description of the revised PGV Project, drawing comparisons with the previously proposed PGV Project, as appropriate. A more detailed description of the revised PGV Project follows in Chapter 3, organized to follow the requirements of Rule 12, Geothermal Resource Permits, of the county of Hawaii Planning Commission Rules of Practice and Procedure. As required by Rule 12, Chapter 3 of this amended application also summarizes the PGV Project potential environmental impacts and mitigation measures. See Appendix A for a list of abbreviations used in this GRP Application.