Case Study

Eigg Electrification Project

Project design and enabling works

Project Duration: 2 years
Completion date: February 2008
Overall Project Cost: £1.6m

Project Description

On 1st February 2008, the Isle of Eigg Electrification Project switched on for the first time, allowing power generated from renewable energy sources around the island to be supplied to all residents, through the new island wide high voltage distribution network. Synergie was called in to design the project and complete enabling works prior to build beginning.

The system will generate over 95% of the island’s annual energy requirements, through a combination of Hydro Electric, Wind Power and Solar Energy. This is believed to be the first time that anyone has successfully integrated these three renewable energy sources.

To ensure that constant power can be provided, a battery storage system was designed which will compensate for periods of up to 24 hours, where energy from renewable sources is not available.  Two 80kW diesel generators have also been installed to provide emergency back-up and to supplement the supply, should the output from the renewable sources be lower than the demand.

The system is fed from 3 main energy sources:
- Hydroelectricity: a 100kW hydro scheme at located at Laig, and 2 smaller 6kW schemes at Kildonan and the pier.
- Windpower: a 24kW wind farm comprising four 6 kW Proven wind turbines on 15m masts are located at Grulin on the south of the island.
- Solar energy: a 10kW Photovoltaic Array at Glebe.

The total cost of the scheme was £1.6 million. The generation system comprises a new 100kW Hydro Scheme, four 6kW wind turbines, 9.5kW photovoltaic system, battery inverter system and two diesel generators.  The distributing system comprises 9 HV to LV transformer stations, 11km of HV cable and 9km of LV cabling, meters and changeover switches in each property.

Each of these systems in their remote locations, and the 45 households, 20 businesses and 6 community buildings on the island, are linked together by 11km of buried cable that forms a high voltage network, linking generation with consumption.

Synergie’s project design and enabling works were carried out during 2006 and early 2007, before the main design and build contract was awarded to Scottish Hydro Contracting in April 2007.