The Nuts and Bolts of Kauai Solar and Battery Storage

The Kauai Island Utility Cooperative (KIUC) is a small utility. It provides electricity to about 33,000 homes and businesses on Kauai and has about 25,000 active members. Energy cooperatives are organizations that provide power to their customers, who own a share of the cooperative as  members and ratepayers. The organization is run as a nonprofit, and in the case of KIUC, owns the power plants, and the transmission and distribution infrastructure to bring the electricity to the customer.

Rural electric cooperatives serve 75% of the geographic U.S., but only 12% of the population because there are fewer people to serve per mile of transmission line in rural areas. Cooperatives were founded as a way to electrify parts of the country where investor-owned power companies didn't want to go because it was less lucrative.  Because member-owned cooperatives have no shareholders, the cooperatives serve only their members (the electricity customers) and their employees. 

The cooperative model, especially in rural area or islands, has produced amazing developments in the power sector, and innovation that some for-profit companies have not been able to achieve.

In March of this year, KIUC and Tesla completed a solar and battery storage facility in Lihue, Kauai on a former sugar plantation

 It is a 13 MW solar farm ( 2600 times the capacity of the average 5kW PV system found on an American rooftop), with an accompanying 52Mwh worth of battery storage, making the installation one of the biggest battery energy storage facilities in the country, behind utility scale battery deployment in Southern California. There are 272 Tesla Powerpacks set up next to 55,000 solar panels  According to KIUC, there are many sunny days when 90 percent or more of day time electricity demand is met by the island’s solar farms. The batteries can power 4500 homes for four hours, or about 18% of the island’s homes. 

On islands it is often easier to make the financials work for new, creative power solutions because they typically face a high price of electricity to start.

This is also part of the reason that Block Island Wind Farm came to be, which is the only operational offshore wind farm in the United States, which serves Block Island and its cooperative power company (Block Island Power Company). Prior to receiving power from the wind farm, Block island was also dependent on diesel fuel, importing nearly 1 million gallons of diesel every year.

Kauai is still dependent on oil for a large part of its power supply. About 60% of the electricity on the island comes from oil power plants, and the other 40% from renewable energy sources, including solar+battery, hydropower and biomass. The solar and battery storage facility displaces 1.6 million gallons of diesel per year, enough to fill a Tacoma truck 76,000 times.

Hawaii has a state goal to be powered by 100% renewable energy sources by 2045.