Hawaii is planning to modernise its airports with new energy-efficient and green technologies, which will reduce energy usage by 49% and help the state save around $518m in energy costs in the next 20 years.

The energy-efficiency programme is part of Hawaii Governor Neil Abercrombie’s aim to use 70% clean energy in the state by 2030.

The state has signed a $150m contract with Johnson Controls through a state competitive procurement process for Energy Performance Contracting (EPC).

"In just two years the state will be reaping the energy savings."

The project includes replacement of 372 transformers and 74,500 light fixtures, installation of 9,100 solar photovoltaic panels, installation of smart controls, roof repairs, and replacement of chilled water and air conditioning systems.

Abercrombie said: "These important upgrades at our airports will help Hawaii reach its clean energy goals.

"This project is a long-term investment, which will cut the energy use at our airports nearly in half, reduce our dependence on imported energy sources, provide savings on future energy costs and add jobs to our economy."

The project is being carried out by Department of Transport Airports Division in collaboration with the state Department of Business, Economic Development, and Tourism (DBEDT). It is expected to add more than 400 jobs and generate $670m in economic development.

DOT Airports deputy director Ford Fuchigami said: "In just two years the state will be reaping the energy savings and cost benefits of this programme with a guaranteed savings of $15.8m."