Samoa has installed a battery energy storage system, a first of its kind in the Pacific islands.
The $US8.8 million project at the Fiaga Power Station is capable of storing six megawatts of electricity.
A second unit near Faleolo Airport will add an addition two megawatts capacity.
Prime Minister Tuilaepa Sailele Malielegaoi says the system will make Samoa's power supply stable and cost-effective.
He says its more environmentally-friendly than diesel generators.
The system, which has been installed by the American company Solar City-Tesla, will kick in when power consumption is high to relieve pressure on the network.