Hawaiian Electric on March 8 filed an application with the Hawai’i Public Utilities Commission requesting that the commission conduct a public hearing for the Mauka FIT One 46-kV overhead extension from an existing 46-kV overhead subtransmission line near residential areas; and that the commission determine that the extension of the 46-kV subtransmission line be built above the surface of the ground.
Mauka FIT One LLC will develop and install a Tier 3 feed-in tariff (FIT) 3.5-MW solar farm in Kahuku, on the island of O’ahu, Hawaiian Electric said, adding that the proposed Mauka FIT One 46-kV Overhead Extension Project (OEP) includes about 27 poles and 3,400 circuit feet of 46-kV overhead conductors. The OEP is needed to interconnect the Mauka FIT One Tier 3 FIT facility to Hawaiian Electric’s system.
Hawaiian Electric also said that the estimated cost of the OEP is about $1m, which is one of four components of the approximately $5.5m total estimated interconnection cost set forth in the Mauka FIT One Tier 3 FIT power purchase agreement (PPA). Mauka FIT One will pay for all of the interconnection costs under the PPA, including the cost of the OEP.
Hawaiian Electric also noted that the OEP was initiated at the request of Mauka FIT One in order to accommodate the development and installation of a Tier 3 FIT 3.5-MW solar farm on real property situated in Kahuku. Mauka FIT One has requested that the existing 46-kV overhead line be extended along Charlie Road, which is owned by Continental Pacific LLC and Kahuku Wind Power LLC, where it would connect to a substation for the solar farm. Hawaiian Electric added that it will be granted an easement to cover the 46-kV overhead line extension.
The benefits, if any, of placing the 46-kV line underground do not outweigh the costs, Hawaiian Electric said, adding that it estimates that it would cost about three times more to underground the 46-kV line than to build it overhead – that is based on an estimated capital cost of about $3.5m for an underground 46-kV line versus an estimated capital cost of about $1m for an overhead 46-kV line.
The company also said that the visual impact will not be significantly increased, as there is an existing 12-kV overhead line along a portion of Charlie Road.
Construction of its facilities for the OEP is expected to start in February 2019, and be completed by April 2019, Hawaiian Electric said, adding that its construction schedule is dependent on Mauka FIT One’s construction schedule.