Narec (National Renewable Energy Centre) Distributed Energy, looked at alternative means of generating power for the island at the request of Sark’s electricity prices control commissioner.
NDE states that it is an independent commercial consultancy, specialising in renewable energy technologies, energy storage and electricity grid connections.
Its report was split into sections looking at power for the grid as a whole, as well as domestic and hotel supplies.
Research for an island-wide grid encompassed wind turbines and solar power with batteries, while solar, battery and diesel was considered for individual properties.
NDE suggested that a 46m-high (from ground to hub, 77m from ground to tip) 500kW turbine plus a solar farm capable of generating 3,000 kWp (kilowatt peak, that is the peak amount of power generated), plus 7,500kWh of battery storage would be sufficient.
As an alternative to the traditional fan-like wind turbine, the report said that islanders might prefer a vertical blade turbine which could be regarded as more aesthetically pleasing.
The cost of the grid construction using the normal turbine would be just over £11m. In its domestic section, the report looked at the likely cost of electricity in a four-bedroom house using solar panels and batteries, backed up by a diesel generator for emergencies.
Using a 7.36kWp photovoltaic array would, over 20 years, see such a property paying 42p per unit.
In the case of a hotel, it would need a 165kWac photovoltaic array which would result in a cost of 51p per unit over a 20-year period (before the consideration of any bond that might be taken out to pay for the system, which could increase the cost depending on the interest payable).
But NDE said that the price of power supplied by Sark Electricity over 20 years would likely increase, and anticipated that in 20 years’ time it would expect electricity prices to rise by an average of 5% a year, meaning the average price over that time could be £1.13 per unit.
The idea has already attracted opposition, and in the latest edition of the Sark newspaper a letter from ‘a concerned Sark resident’, accompanied by a scaled drawing of the proposed turbine next to a tower block, urged islanders to ‘stop this madness without further ado’.
‘[It] is beyond comprehension that we should consider the construction of such a monstrosity on our island,’ wrote the author.
Guernsey power station’s chimneys are 55m high.