Haw. Rev. Stat. § 269-101
As used in this part:
"Eligible customer-generator" means a metered residential or commercial customer, including a government entity, of an electric utility who owns and operates a solar, wind turbine, biomass, or hydroelectric energy generating facility, or a hybrid system consisting of two or more of these facilities, that is:
(1) Located on the customer's premises;
(2) Operated in parallel with the utility's transmission and distribution facilities;
(3) In conformance with the utility's interconnection requirements; and
(4) Intended primarily to offset part or all of the customer's own electrical requirements.
"Net energy metering" means measuring the difference between the electricity supplied through the electric grid and the electricity generated by an eligible customer-generator and fed back to the electric grid over a monthly billing period; provided that:
(1) Net energy metering shall be accomplished using a single meter capable of registering the flow of electricity in two directions;
(2) An additional meter or meters to monitor the flow of electricity in each direction may be installed with the consent of the customer-generator, at the expense of the electric utility, and the additional metering shall be used only to provide the information necessary to accurately bill or credit the customer-generator, or to collect solar, wind turbine, biomass, or hydroelectric energy generating system performance information for research purposes;
(3) If the existing electrical meter of an eligible customer-generator is not capable of measuring the flow of electricity in two directions, the electric utility shall be responsible for all expenses involved in purchasing and installing a meter that is able to measure electricity flow in two directions;
(4) If an additional meter or meters are installed, the net energy metering calculation shall yield a result identical to that of a single meter; and
(5) An eligible customer-generator who already owns an existing solar, wind turbine, biomass, or hydroelectric energy generating facility, or a hybrid system consisting of two or more of these facilities, is eligible to receive net energy metering service in accordance with this part.
HRS § 269-101