Hawaiian Electric Companies filed contracts for seven grid-scale, solar-plus-storage projects on three islands to state regulators for review.

The projects – three on Oahu, two on Maui and two on Hawaii Island – would add around 262 megawatts (MW) of solar energy with 1,048 megawatt-hours (MWh) of storage. The energy storage is intended to provide four hours of electricity.

The companies said that in the 10 years since the state created the Hawaii Clean Energy Initiative, they have reduced fossil fuel use by 26%. The islands depend on fuel oil for a large part of their generating capacity, so the reduction amounts to about 48 million fewer gallons of oil shipped to the state. The seven projects, if approved by regulators, could nearly double that reduction to 100 million gallons when compared to 2008.

Fossil fuel generation costs about 15 cents per kilowatt-hour, the utilities said. The prices for six of the seven projects would rank among the lowest to date for renewable electricity in the state.

The proposed projects include the following:

  • 30 MW of solar and 120 MWh of storage developed by AES at a cost of $0.08/kWh
  • 30 MW of solar and 120 MWh of energy storage developed by Innergex at a cost of $0.09/kWh
  • 60 MW of solar and 240 MWh of energy storage developed by AES at a cost of $0.08/kWh
  • 15 MW of solar and 60 MWh of energy storage developed by Innergex at a cost of $0.12/kWh
  • 52 MW of solar and 208 MWh of energy storage developed by 174 Global Power at a cost of $0.10/kWh
  • 39 MW of solar and 156 MWh of energy storage developed by Clearway at a cost of $0.09/kWh
  • 36 MW of solar and 144 MWh of energy storage developed by Clearway at a cost of $0.10/kWh.

These seven solar-plus-storage projects stem from a procurement effort the companies began in February 2018. An additional project, a 12.5 MW solar array in West Oahu that would include a 50 MWh storage system, is also being planned. The contract is expected to be submitted to regulators in the coming weeks.

Hawaiian Electric, Maui Electric and Hawaii Electric Light currently have more than 500 MW of renewable energy under contract in addition to nearly 80,000 private rooftop solar energy systems in operation. The cost of renewable energy continues to drop, aided by tax credits available to developers.