Size comparison of small-scale versus industrial scale wind turbine image: Carbon Trust
Most of the time when we talk about wind energy, the turbines referred to are of the couple-hundred feet tall behemoth variety. But it’s not just the big boys which can have a place in reducing our demand for fossil fuels. A new report from the Carbon Trust details the potential of small-scale wind turbines in the UK, how much power could be produced and how much carbon emissions could be avoided.
Setting the Scale
For the purpose of the report, the Carbon Trust classifies small-scale wind energy as any turbine rated less than 50 kW, generally intended to supply buildings and which may or not be connected to the electric grid. It is pointed out that these turbines require many of the same wind conditions which larger turbines require and are best utilized in rural areas.
That said, while larger turbines may have capacity factors of 28-35%, on average, small-scale turbines, because of their height small-scale turbines only achieve 15-20% of their rated capacity in rural areas, and only 10% in urban areas.
Cost of Turbines and Electricity Limits Installations
Theoretically, small-scale wind energy has the potential to generate 41.3 Terrawatt-Hours of electricity an save 17.8 Million tonnes of CO2 annually.
However, given installation and current electricity costs, the Carbon Trust assumes that only 10% of households can realistically install small-scale wind turbines. If this happened, up to 1.5 TWh of electricity could be generated, and 600,000 tonnes of CO2 emissions avoided.
This amount of electricity is a mere 0.4% of total UK electricity consumption.
The report goes on to note, that in urban areas roof-mounted turbines may never pay back their embedded carbon emissions.
The obvious thing that this study says to me is that there is great overall potential for expansion of small-scale wind energy. While it may never be able to compete with gigawatt-sized wind farms in terms of total output, there is certainly a place for this sort of technology. Certainly the visual impact of these turbines is much less than industrial-scale turbines and that alone is a plus in my book. Move the big boys offshore and expand small-scale wind in rural areas onshore.