Editor's Note: The following are selected excerpts from the Renewable Energy Foundation press release describing this research. The full press release is available via the link below.

Using the new research it is now possible to assess how renewable generators up and down the country are performing. This data, published in five online files; Biomass, Hydro, Landfill Gas, Sewage Gas and Windpower, shows that firm generators are producing high load factors with carefully designed resource use and load following.

However in the wind sector, far and away the most active of all the technologies at present, results vary enormously due to location. The capacities offshore are encouraging, whilst those onshore are generally only superior in locations very distant from the populations requiring the electrical energy.

Although most sites were built on expected capacity factors of around 30%, results include;
19% (approx) capacity factor for the wind turbines at Dagenham, Essex.
9% (approx) capacity factor at the Barnard Castle plant, County Durham.

The best performing wind sites are in the north of Scotland, and on Shetland the wind turbines are producing capacity factors of over 50%.

Using this analysis of the Ofgem data, researchers have also calibrated a model predicting how a large installed capacity of wind power built across the UK would actually perform. The project used Meteorological Office data to model output for every hour of every January from 1994-2006.

The startling results show that, even when distributed UK wide, the output is still highly volatile.

The average January power variation over the last 12 years is 94% of installed capacity. It is an uncontrolled variation decided by the weather.

The average minimum output is only 3.7% or 0.9GW in a 25GW system.

Power swings of 70% in 30 hours are the norm in January.

The governments’ expectation is that three quarters of the 2010 renewables target, and the lion’s share of the ‘20% by 2020’ target will be made up of windpower.[2] However, the new research offers predictions which are in keeping with Danish and German empirical experience and demonstrate the need for a broader spread of investment in the renewable sector. <br.
The report was commissioned from Oswald Consultancy Limited and funded by donation from the green entrepreneur Vincent Tchenguiz.

Campbell Dunford, CEO of REF, said: “This important modelling exercise shows that even with best efforts a large wind carpet in the UK would have a low capacity credit, and be a real handful to manage. This isn’t the best way to encourage China and India to move towards the low-carbon economy. As a matter of urgency, for the planet’s sake, we need to bring forward a much broader range of low carbon generating technologies, including the full sweep of renewables. Wind has a place, but it must not be allowed to squeeze out other technologies that have more to offer.”

This report is based on data provided by the International Energy Agency, the Department of Trade & Industry, the Royal Academy of Engineering, Princeton University and a number of other respected sources. It sets out an agenda for Government in the short term and the long term, answering the key issues raised by the Government's current Energy Review related to power generation: the economy, the environment and security of supply.

The values in Table 2 are based on total availability and reflect the time that the turbines are available to operate. Hence, no allowance is made for the effects of grid outages or ‘weather days’ which could prevent access to turbines for repairs. The planned availability was exceeded for only one month and the availability across the site was below expectation especially during the autumn period. This was due almost entirely to problems with bearings in the gearbox as will be discussed in Operational Issues.

Built in 2003, North Hoyle is the UK's first major offshore wind plant.....