Swept area

The Swift has a blade diameter of 2.10 metres. This means it has a swept area, or capture area of 3.46 square metres. The swept area is all important when comparing wind turbines, since it directly relates to the amount of passing wind energy the turbine blades can intercept.

Swift power output curve

The graph below shows the power produced (in watts) for the Swift at different wind speeds, based on data supplied by the manufacturer.

Whilst the above graph gives an indication of the instantaneous power you might expect from the Swift turbine, working out annual power production is more complex. The only way to know for sure is by measuring your wind speeds using an anemometer for a period of time and then working out what a generator like this would produce. Luckily, we've invented something that makes this easy, called the Power Predictor!

The power output curve as published by Swift is shown below.

Around £5,500 for the system, plus installation which would probably cost about £1,500. The Swift is eligible for grant funding from the Low Carbon Building Programme and the Scottish Community and Householders Renewables Initiative (30% domestic and 50% community) bringing the final capital cost to the end user down to between £3500 and £5000. You must use an accredited installer (you cannot DIY).

An exciting proposition, especially as the claims say there is virtually no noise. It's an elegant design, but when we saw one at an exhibition, it seemed like a fairly large thing to be strapping to the side of your house, and there are of course well-documented problems with roof-mounted machines (as mentioned elsewhere on this site and others).

2.10 metres

1400

Swift have government accreditation so the turbines are eligible for up to 30% grant funding depending on where you live in the UK.

Unclear, but expected lifespan of 20 years

Renewable Devices / Swift

0131 535 3301