Water, in the form of hydro electric, generates the greatest amount of renewable power with up to 100kW. The four wind turbines generate up to 24kW. Photo voltaic solar panels (PVs), which capture energy from the sun, generate a maximum of 10kW – 10% of the generating capacity of the hydro electric. A bank of batteries, capable of providing power to the whole island for up to 24hrs, has been designed into the scheme to enable us to optimise our usage of energy from the renewable resources. To cover occasions when renewable generation is low, the system is supported by a pair of 70kW diesel generators, which act alternately as back up and reserve.
During the summer months, when there is less wind and rain, the island is more reliant on the photovoltaic solar panels & in this instance when the batteries are draining faster than energy is being produced, the generators automatically come on to charge up the batteries.
Diesel generators are very expensive to run and create carbon emissions. In order to reduce the amount of diesel the generator’s burn, the simplest solution is to ask that residents use less power. This keeps costs down and creates less carbon emissions. This is not a mandatory requirement, simply a request which most residents are happy to respond to, as they understand the benefits of reducing their energy demands far outweigh the consequences of using more diesel – higher unit cost to the user and increased carbon emissions. Not using an electric kettle, iron, toaster, or even
washing machine at peak demand times is not a difficult thing to do. If everyone uses a little bit less, then there will always be enough for us all until the renewable sources of wind and rain return.
Eigg Electric has plans to add a further 20kW of solar photovoltaic panels to the system later this year. This will mean that electricity will still be generated if water or wind is in low supply and that 98% of all Eigg’s power will come from renewable sources, rather than being reliant on oil powered generators.
Like Eigg, the UK grid is only capable of producing up to a maximum amount of power. If all UK residents were to demand more from their grid than it was capable of supplying then, like what happens with water shortages, they would be asked to reduce their demand.
On Eigg we are able to do this simply and without fuss. Residents understand how their power is generated and therefore what demand they are able to make of it. For the vast majority of the year islanders have all the power they need. At the moment, for a relatively short period of time, they understand why they need to reduce that demand and as a community are able to do so.
We look forward to the rain, and the wind, and welcoming people to ask questions or come to visit and find out more about our electricity scheme, of which we are very proud and very pleased with.