Student:
above: Components of the off-grid system: PV arrays, wind turbines, battery bank, diesel generator, inverters system, 6 kW hydro turbine.
María González Rodríguez De Biedma Study:
The Isle of Eigg : A unique off-grid system Keywords:
energy, sustainable community The island of Eigg is part of the Small Isles Archipelago in the Scottish Inner Hebrides, 12 miles away from the Scottish west coast. It only counts with 83 inhabitants which form a strongly linked community, that decided to make the first community buyout of an island in 1997. This new independence from certain government restraints allowed the community to propose an off-grid electric system to generate self-sufficient energy that would be respectful with the environment and would take advantage of the isle’ harsh weather conditions. As an exception to other off-grid systems proposed , this one is the first to rely on three renewable energy sources coming from the water, the air and the sun. The system has been proved to have outstanding results as it generates energy and carefully distributes it to the population, generating a 24/7 electricity supply. The key in this system relies on understanding the natural conditions of the island, if there is a drier winter the system will take energy from the wind, if there isn’t enough sun, it will rely on rain and vice versa. The system counts with an installed total capacity of 357kW, the battery bank system allows the energy storage and the inverter system controls the frequency and voltage of the grid depending on the energy loads and the demand. It is interesting to highlight that in order to avoid a saturation of the system all islanders have a limit use of 5kW each per day when normally the limit for commercial properties is of 10kW, however studies have proved that inhabitants consume just page 18
20% of the total load allowed. The whole system is interconnected along the island through an 11km under-ground high voltage distribution system. This successfully implemented self-sufficient energy example makes this island as well more eco friendly as its CO2 emission per household in the island is 20% lower than the rest of the UK . Inhabitants remark that living in the island isn’t easy but it is understood as a lifestyle that is sustainable and in touch with nature. Not only their energy system is sustainable but also their economical activity which mainly relies on eco tourism, production of beautiful crafts and textiles or even a small local beer brewing. Moreover, key to the functioning of this self-sufficient system is the strong sense of community that all inhabitants have. It is that spirit that allowed the island to bring big changes that have improved the live standards of the population, all islanders have a say in the island management decisions and that involves them in the cause, making it easier for everyone to respect the rules, understand the system and peacefully cohabit with their neighbors. Nevertheless, as a matter of critique, the mobility of this island is poorly developed as it completely relies on the use of cars, not a very sustainable source.This matter could also be tackled in the future if the isle keeps evolving and increasing its population, in order to keep the island as a sustainable example for future self-sufficient projects.
