Comenius

The best known example of stand alone wind generating systems is on Fair Isle, the most isolated island community off the British coast.

Wind turbines have being supplying electricity for almost 40 years to a cluster of 20 dwellings and the load is matched to the turbine output by varying the frequency from 48 to 55 Hz and having a set of frequency switches which switch loads on or off in each dwelling.

On Foula, another isolated island adjacent to Shetland, use has been made of the availability of an upper and lower loch. When there is an excess of power, water can be pumped from the lower to the upper loch. When demand exceeds supply, water can be released from the upper loch to drive an axial flow generator which produces electricity. The concept of pumped storage is not new and has been widely used to match the demand and supply of the national grid such as in the UK.

For smaller turbines, battery storage would be the most common medium.

Combining different types of renewable electricity sources is common and wind and PV are generally a good combination as PV peaks in the summer and wind in the winter in much of Europe.