Meanwhile, also on Lewis

Elsewhere in the Western Isles, and in an announcement with slightly unusual timing, npower has announced that it has formally submitted a planning application for the 4MW wave-powered breakwater project at Siadar.

With the recent "no" decision on the Barvas Moor project, it will be interesting to see if the active community in the Western Isles is supportive of this much smaller project or not.

With 4MW of installed capacity, average output might be 1MW (based on a capacity factor of 25%). The usual rule of thumb is that a household uses c. 5,000 kWhr/yr. This is an average of just over half a kW - which sounds low to me, especially for the often electrically-heated Western Isles. If this is right, this project could power around 2,000 houses. There are probably 6,000-10,000 homes on Lewis (based on 2-3 people per home, and Wikipedia's population figure of 19,000), and if this average power usage figure is right, this would mean that 20% - 33% of local homes would be powered by this project.

There are many heroic assumptions in this back of an envelope assessment, but it's clear that the project could make a real local impact.