Makogai, Fiji: island power for the giant clams

Makogai is a small island in Fiji’s Lomaiviti group, home to the Makogai Mariculture Research Centre, which raises giant clams and returns them to the sea. After Cyclone Winston swept through the centre and its clams in 2016, Korea’s Ministry of Oceans and Fisheries and the Korea Institute of Ocean Science and Technology (KIOST) have been rebuilding it with the Fijian government. Giant clams are a priority species in Fiji’s aquaculture development plan, and the centre has hosted the Pacific’s first regional giant clam hatchery training.

Sun for the clams, power for the pumps

The island has no grid, so the centre relies on diesel, and its clam tanks need seawater pumped in around the clock. When the power fails, the clams are lost. ENVELOPS is designing and building an off-grid hybrid microgrid for the centre that ties together solar, battery storage and a standby diesel generator. Solar runs the pumps by day and the battery by night, with diesel kept only as a reserve. Giant clams grow on the photosynthesis of the algae in their tissue and need full sun, so the panels stand on separate land beside the centre rather than over the tanks. It is agrivoltaics turned around: the sunlight goes to the clams and the electricity to the pumps.

Next

The basic design is complete, and the aim is to build in 2027 and hand the system over to the centre by the end of that year. The island lies in the strongest cyclone wind zone, the ground is coral and the surrounding sea is a marine protected area, so the structure, the earthing and even the shipping of materials have been designed around the island. Operator training and remote monitoring will help the centre run the system itself.