Solar Rapidly Expands in Hawaii

Solar power is really growing in Hawaii, as a recent report from the Energy Information Administration (EIA) shows. Over the last five years, solar power has grown exponentially, particularly in Oahu where most of the state’s population lives: About 12 percent of Oahu residents have rooftop solar, compared to the U.S. average of 0.50 percent.

As larger and more efficient solar photovoltaic (PV) systems are installed, the average capacity of residential net-metered PV systems has been increasing all over Hawaii.

Hawaii is unique when it comes to energy fuels in that it imports all that the state needs, and a large share of the state’s power comes from oil-fired generators. Hawaii’s electricity prices are the highest in the U.S. and that makes wind and solar power “economically attractive alternatives,” as the EIA report states.

But there are problems: Delays are slowing residential solar PV additions. Local utility Hawaiian Electric's distribution grids are reaching rooftop PV capacity levels of 120 percent or more of the circuit’s daytime maximum load. When that threshold is surpassed, an interconnection study may be required before a new PV system is approved, and that has caused a backlog of applications, according to the report.

Hawaiian Electric, which owns three electric utilities that supply power to 95 percent of Hawaii’s population, entered into a research partnership with the National Renewable Energy Laboratory, the Electric Power Research Institute and SolarCity to study the operational effects of high solar PV levels on electric grids. Hawaiian Electric has announced plans to clear its backlog of PV applications by April 2015, as a result of preliminary research results.

The utility has also proposed to raise the allowable PV penetration from 120 percent to 250 percent of a circuit’s daytime minimum load in a filing with the Hawaii Public Utilities Commission. However, this increase would mean a decrease in the amount received by new net-metered PV customers for the excess electricity they send back to the grid.

Additionally, Hawaiian Electric is working on energy storage projects, including batteries. It will be deploying 500 to 100 PV/battery systems on circuits that have high amounts of solar, according to the company’s website, which can help increase the amount of PV systems that can be added. That will help Hawaii Electric meet its goal of tripling the amount of distributed solar and increase renewable energy to over 65 percent of energy used.

Image credit: Official U.S. Navy Page