Onshore wind energy
For onshore wind farms, concrete is already the established material of choice for foundations, either to form gravity structures or pile caps. For towers, the foreseeable trend is for increasing height, supporting higher powered, longer-bladed turbines, many of which may be located at remote or less accessible sites. The consequence of taller towers is the need for increased structural strength and stiffness required to cope with challenging turbine weights and bending forces under wind action. In turn this will require larger cross-sectional diameters, which may introduce significant transportation problems; bearing in mind that 4.5m is the practical diameter limit for complete ring sections on public highways.
Concrete towers can cost-effectively accommodate these requirements as well as offering a range of other associated benefits. Already, many leading wind power companies have realised the benefits of concrete and offer precast or in-situ concrete tower solutions.
Whitelees Onshore Wind Farm
Whitelee wind farm, near Glasgow, was developed by ScottishPower through principal contractors Morrison Balfour Kilpatrick. The objective was to find a locally sourced cementitious solution and a sustainable product with lower embodied CO2 for a construction project focused on providing renewable energy. The product also had to be suitable for large concrete pours required for the foundations and bases of 215 wind turbines on the 5,300 hectare site, an area roughly the size of Aberdeen.
Base of onshore wind tower using in-situ concrete
Buttress of onshore wind tower using in-situ concrete