Wind eases uphill fuel delivery

A cattle farm on a remote island 300 kilometres south of Tokyo has installed a wind-diesel hybrid system as its independent power supply. The farm is located halfway up Hachijo Island's 854 metre high mountain where the local government breeds young cattle as a service to farmers. With no link to the grid, the farm manager has until now been reliant on carting oil up the hill to feed a diesel generator.

The new system consists of four 5 kW wind turbines from Vergnet SA of France, a company specialising in small wind turbines and combined power systems in rural areas (Windpower Monthly, February 1997). A "static power pack" controls the power supply by means of a bi-directional 10 kVA three-phase inverter from Prime Power Systems of Australia, a battery bank from Germany and the existing 20 kVA three phase diesel unit. The manual generator was modified to be automatically controlled by the power pack.

The system supplies electricity to the cattle farm as well as an adjoining rest house, which includes vending machines and freezers for tourists and visitors. If the wind is weak and the batteries run low, or the power load exceeds the inverter's capacity, the diesel kicks in. The system is made to accept a second diesel generator for future increases in power demand. According to meteorological data at the foot of the mountain, the annual average wind speed is 7.3 m/s, while on 241 days a year it averages more than 10 m/s.

The system was installed by Inter-Domain Ltd of Yokohama. General manager Shin Sugimoto believes that this type of system has a rosy future on many other islands around Japan's shores, especially where the cost of fuel transportation is high.