Island runs on renewable energy

Imagine living in a community where all of your electrical power needs are furnished by wind, water and sun. This sounds like an environmentalists dream.

The people of the Isle of Eigg Scotland have decided to make this dream a reality. They have embraced the renewable energy promise and have adopted a 24 hour dependence on sun, water and wind to provide all of their energy needs. I applaud their faith and look forward to tracking their attempt to prove, or disprove, the premise that we can live in comfort without fossil fuels to provide heating, air conditioning, lighting, cooking, etc.

Many communities talk about lessening their carbon footprint but this small community, of just under 100, actually put the idea into play. On Feb 1, 2008, their tiny island, 9k (5.6 miles) long and 5k (3.7 miles) wide, began the great experiment to see if renewable energy can be accommodated within distribution networks.

In the past, the people of Eigg had only limited access to electricity depending entirely on black-smoke-belching, unreliable diesel generators. These old generators have been updated and will now be relegated to the role of backup in case of emergency. It seems they cannot completely remove themselves from the oil companies umbilical cord just yet.

Their power grid now incorporates a 9.9 kWp Photo Voltaic system, three hydro generation systems (totaling 112 kW) and a 24 kW wind farm of five wind turbines that will utilize a bank of batteries to guarantee continuous availability of electrical power. Power is distributed to the island's 45 households, 20 businesses and six community buildings via a 6-mile long buried cable. A load management system has been installed to optimally distribute the energy captured.

The battery system
The systems' twelve battery inverters are the heart of the system and control the system voltage and frequency, and manage the balance between loads and generation by controlling the power into and out of the batteries. Additional system control will be provided by load management at times of high renewable generation.

The inverters make up four clusters, each consisting of 24 batteries with a total energy storage capacity of 212kWh.

Solar Panel array
This array will be at its highest value during summer month when hydro generation and wind turbines are expected to be at their lowest output phases. This is where the diesel generators are most likely to be needed to provide continuous electrical power.

The array consists of 60 modules connecting the network via grid-connect inverters which will allow the PV output to feed the island loads directly. Surplus output is stored in the batteries.

Wind turbines
Four turbines on 15m towers each connected to inverters are sited at the Southern end of the island where the best wind exposure is obtained.







It is estimated that this complete system will save 10 tons of CO2 per year. Note: I have not found any information on how much CO2 this island created previously but I am certain that this 10 ton figure is based on what the island would have created had it been electrically powered 24/7 by those old diesel generators, which it had not.

But the success of this test will go a long way to providing much needed encouragement for other off-grid communities to adopt these cleaner, more sustainable resources for their electrical power, as well as provide proof that renewable energy can be incorporated into existing networks to help achieve co2 reduction targets.

The island made history once before when it became the first successful community buy-out. In 1997, after decades of mismanagement by absentee landlords, the island was bought by the Isle of Eigg Heritage Trust, a partnership between the residents of Eigg, the Highland Council, and the Scottish Wildlife Trust. Visit www.isleofeigg.org for more information.

I am interested in learning how far the people of Eigg are willing to take their commitment to a more sustainable, greener lifestyle. Do they recycle? Do they grow their own food? What do they do with their garbage?

If anyone knows the answers to these questions I would like to hear from you. I will do some research to see what I can learn and post it here.

Now, go out and green your world.