Hawaiian island of Kaua‘i, which has reached 97% penetration of renewables in daylight hours, will use Tesla battery system to extend solar into peak evening consumption.
Hawaii has moved closer to its goal of getting 100% of its electricity from renewables by 2045 with a photovoltaic installation that includes a battery system to extend the provision of solar energy after sunset.
The installation is part of Hawaii’s response to the difficulty of integrating increasing amounts of intermittent renewable power. The cooperative that runs the power system on Kaua‘i Island said the plant was the first time a utility had contracted a system of this scale that stores and will deliver solar energy into the night for its 33,000 customers.
The Tesla system feeds up to 13 MW of power into the island’s grid to meet peak demand in the evening hours thanks to a 52 MWh Tesla Powerpack lithium-ion battery storage system. The solution is critical for increasing penetration of renewables since the grid cannot take more daytime solar power (it’s already at 97% during daylight hours).
“By using solar energy stored in the battery after the sun goes down, we will reduce our use of imported fuels and our greenhouse gas emissions significantly,” said Chief Executive Officer David Bissell at a blessing ceremony. He estimated the project would displace the use of 1.6 million gallons (6 million litres) of diesel a year and take Kaua‘i Island to more than 40% renewable generation.
The project makes financial sense too. Under the terms of the 20-year contract, the cooperative will pay Tesla 13.9 cents per kilowatt-hour, less than the current cost of oil.