Operating costs vary widely - from £ 70k to £ 200k p. MW p.a.
Why there is such a wide variation in these costs between windfarms is not clear.
Efficiency of daily operation: cost per MWh generated.
Efficiency of the equipment, capital cost per MWh.
Companies allocate the historical cost of fixed assets in equal amounts across their useful life, and so, due to inflation, the amount allocated declines in real terms each year. Accordingly the historical depreciation charge has been adjusted for inflation using the following table.
Putting the two KPIs together gives an indication of overall efficiency.