In January 2019, the AES Lwai PV peaker plant began providing evening and morning renewable peaking capacity to the transmission system on the island of Kauai. The solar-plus-storage system promises to ensure a sustainable future for the island and establish a new model for stabilizing grid-scale renewable energy. Instead of simply augmenting traditional generation, solar-plus-storage sequentially can replace it altogether.
It is remarkable — by obtaining fixed pricing for dispatchable solar-based renewable energy, backed by a significant battery system — the overall cost of this PV peaker plant is about half that required for a basic direct-to-grid solar project a few years ago. This project is now expected to deliver power to the island’s electrical infrastructure at a cost significantly less than that of the current cost of oil-fired power, which will help to stabilize the tariff rates for KIUC’s customers.
This project will remove the annual economic cost and environmental impact of 3.5 million barrels (556 million liters) of oil. KIUC and AES already have partnered on a second project that includes AES’s 19.3-MW-solar-plus-70-MWh-battery energy storage facility, currently under construction on leased land from the U.S. Department of Defense within the Pacific Missile Range Facility Barking Sands Naval Base. AES expects this solution to become a model for solar-saturated markets where it is necessary to time-shift most of the energy generated.