Electrification of remote villages using micro-hydro
by APACE, Australia

Vavanga Community  in the Solomon Islands is one of many villages that use electricity produced by a micro-hydro scheme and there are plans to upgrade the system.

Villagers and project workers celebrate the completion of the new micro-hydro scheme.

Introduction

Vavanga Community is a village on the southwest coast of Kolombangara Island. Before the introduction of hydro electricity, the village had no power source – all members of the community used local wood for cooking and the more prosperous members used kerosene for lighting and dry-cell batteries for radios and torches. Now, as part of a programme of village-based, micro-hydro electricity development projects in the Solomon Islands, Appropriate Technology for Community and Environment (APACE)1 has successfully implemented schemes in many villages, including Vavanga Community.

Background

A micro-hydro generating system provides 10–100 kW of

Villagers learn how to maintain the plant.

power. It works by diverting some of the river flow through a turbine and then uses the energy to turn an electric generator. The water is then returned to the river. The system is a “run of the river” type, ie land is not flooded to create reservoirs or water storage areas for power generation. The turbine runs continuously, therefore, until the community devises a suitable use for excess power generated during “off-peak” periods, some of the electricity produced is not utilised.

The environment in the Solomon Islands is well suited to small-scale hydro power; water is plentiful and, due to the mountainous terrain, the supply is often above the village. On-going costs are low in comparison with either diesel generation, which requires a fuel supply, or solar energy, for which energy storage batteries need to be replaced periodically.

Vavanga Community project

The system at Vavanga Community comprises a timber weir, a four-piped penstock and a 240 V 50 Hz ac synchronous generator with an output of 4–7 kW (depending on the season). Double-insulated 240 V underground cabling is routed around the village and the transmission line also runs underground for the first 500 m from the village. From this point, 3,330 V overhead cabling is connected to the micro-hydro scheme, which is 2 km from the village.

Originally, 22 houses, 14 kitchens, two church buildings and a bakery building were connected to the supply, however, additions have since been made. Typically, two 18 W fluorescent lights and a power point are installed in each household. To enable the river to provide sufficient power for the whole community, current-limiting devices are installed in the households, but unlimited power is supplied at 240 V to the community facilities and businesses.

Each building is connected to one of the village circuits. These are designed to distribute the power in such a way as to create an equal load on each circuit and to take into account the social construction of the community. The latter aspect ensures that if clan disagreements occur, the supply cannot be severed to another clan further along the circuit.

Villagers took an active part in the installation of the system and, because it is “run of the river” generation requiring less complex mechanical knowledge, they have been trained to maintain it. As with other communities assisted by APACE in the Solomon Islands, Vavanga Community has been contracted to maintain and develop its installation. While the equipment was supplied as a grant-in-aid rather than a loan, the village has a tariff system to cover depreciation, operation and maintenance.

Each micro-hydro project is developed as a team effort between APACE and a community hydro committee, which represents all users. The committee organises work plans and makes a range of decisions, including local resource utilisation, local distribution and building designs. Work implementation skills, including engineering and management, developed in the community through the project, can be transferred to other village activities.

The social impact of electrification is managed through training programmes provided by APACE. Some of the long-term changes in Vavanga include slowing the population drift from the village and better village welfare. New infrastructure has also been developed, including:

  • extended electrical circuits for new houses;
  • street lighting;
  • houses repaired, upgraded and well maintained;
  • the building of a new church, private bakery and private stores.

The future

The community has plans to upgrade the system in two major ways. Firstly, the timber weir structure is to be replaced by a reinforced concrete design with an upgraded silt drain to cope better with flood debris. This follows the experience gained by one of Vavanga’s trained operators while managing a more recent APACE installation in New Georgia Province.

Secondly, an additional tributary of the river is to be tapped with a second penstock and small turbine to make more power available for development initiatives over the next 10 years. These initiatives alone refute the widespread belief that rural electrification plants, while socially needed, have low utilisation factors, require continuing subsidies and rarely follow their promised development path. The link between rural energy and sustainable development can be built into the project by full local participation.

For more information contact APACE,
PO Box 123, Broadway, NSW, Australia 2007.
Tel: +02 9514 2554; Fax: +02 9514 2611;
e-mail:
apace@uts.edu.au
Web site:
www.pactok.net.au/docs/apace/home

1 APACE is a non-profit-making, community-based agency, assisting overseas communities in their aspirations for sustainable development.

The CADDET Renewable Energy Newsletter is a quarterly magazine published by  the CADDET Centre for Renewable Energy at ETSU, UK.

The articles published in the Newsletter reflect the opinions of the authors.  They do not necessarily reflect the official view of CADDET.

Enquiries concerning the Newsletter should be addressed to Pauline Toole, Editor, CADDET Centre for  Renewable Energy, ETSU, Harwell, Oxfordshire OX11 0RA, United Kingdom. Tel: +44 1235 432968, Fax: +44 1235 433595.