Council adopts amended PV rules: engineer stamp required when cumulative residential output exceeds 10 kW

After extended discussion about thresholds, cumulative system sizing and permit practices, the Hawaii County Council adopted an amended version of Bill 66 addressing when a licensed electrical engineer must stamp residential photovoltaic (PV) plans.

The final amended ordinance exempts new residential installations that result in a cumulative total output of 10 kilowatts or less from a licensed electrical engineer stamp. Conversely, any new installation or modification that results in a cumulative total output greater than 10 kW must be supported by plans stamped by a licensed electrical engineer. The change closes the procedural gap in which multiple smaller permits could be added at one site without the department reviewing the cumulative system as a whole.

Department staff and building inspectors explained that counties are the authority having jurisdiction for electrical inspections and that the electric utility (HELCO) does not perform code compliance inspections for residential systems under larger thresholds. Public Works and building division staff argued the 10 kW threshold would cover roughly 85% of residential permits while allowing the department to require engineering review on larger or more complex installations, such as battery additions or systems that tie into older electrical infrastructure.

Councilmembers proposed and refined threshold and language options (10 kW, 15 kW, 30 kW) and raised the need for discretionary waiver language. After tabling and reintroducing the amendment language to clarify “cumulative total output,” the council adopted the ordinance as amended. The measure standardizes permitting expectations and instructs building staff to view modifications as part of the total system when assessing the need for an engineer’s stamp.