Since the takeover of the Vanuatu Concession in 2011, Vanuatu Utilities and Infrastructure (VUI) has rebuilt two-thirds of the hydro generation and has replaced or rebuilt four-fifths of the diesel assets while simultaneously extending the network into many previously un-served communities and lowering the power cost to its customers. This O&M project involves electricity supply, transmission, generation, billing and collections for the town of Luganville on Espiritu Santo, which is the largest island in Vanuatu by land area. As a whole, the utility operation has a client base of several thousand customers, most of which are residential customers. There are approximately 350 business, government and high-voltage customers.
The power system consists of a diesel-engine power station located near the center of Luganville and a run-of-river hydro-electric power station on the Sarakata River approximately 22 km from town. Built in 1994/1995, the Sarakata hydro-electric station is connected to the Luganville diesel station by a single-circuit 20kV overhead transmission line which steps down to 5.5kV at a transformer substation just outside of town. Installed at the hydro-electric station are three horizontal axis, Francis turbine-generators, two are rated at 300 kW and one is rated at 600 kW. The distribution system is supplied at 5.5kv high voltage, stepping down to low voltage for supply to consumers. Other sources of distribution are taken from the main 20kV transmission line to supply customers outside of Luganville. The five diesel generators used on this project are manufactured by SDMO of France, based on Cummins high speed diesel engines. There are two 1000 kW units derated to 800 kW, one 720 kW derated to 600 kW, one 520 derated to 400 kW, and one 250 kW a total of 2.85 MW. The transmission consists of 68 km of high voltage cable, of which 52 km is on
