In the 1970s, Kauaʻi burned
sugar cane waste to supply most of their electricity. , the majority of the Kauaʻi's electricity was produced by importing liquid
petroleum, costing $69.3 million in 2006 and $83 million in 2007. By 2011, 92% of KIUC's power came from petroleum. As of 2019, KIUC's fuel mix was 47.2%
fossil fuels, 10.5%
hydroelectric, 9.9% biomass and 32.5%
solar. KIUC has successfully integrated large-scale solar into its grid so that, during daylight hours on most days, 100 percent of its generation comes from renewable sources. In March 2017, KIUC commissioned a 13 MW solar and 13 MW / 52
MWh battery project for 13.9¢/kWh. A proposed solar-charged water pumping system will supply power throughout the night. ==Corporate history==