Renewable sources are a growing part of the state’s energy consumption. That’s especially true on Kauaʻi, where solar remains a key ingredient—but not the only one.
Nearly a third of Kauaʻi’s energy use currently comes from solar power. The Kauaʻi Island Electric Cooperative has two projects underway with AES Hawaiʻi that will add another 33 megawatts of solar energy when they are finished — which would turn solar into the source of 45-percent of the island’s energy use.
Older technologies are also playing a role. A six megawatt hydro-electric plant is in the permitting process and is expected to be on line by next year.
An innovation under development would combine hydro and solar into a delivery system called pumped hydro. This would involve using solar power to pump water to a storage reservoir, where it would be held until needed after sunset. The potential energy of the suspended water effectively acts as a battery — a storage system. After dark, the water could be released as needed to power a turbine and generate electricity — as much as 25 megawatts according to plans.
Putting it all together, more than 40-percent of Kauaʻi’s energy use now comes from renewable sources. The state of Hawaii has a goal of reaching 70-percent renewable energy use by the year 2040. Kauaʻi has that same 70-percent goal, but plans to reach it a decade earlier than the state.