Wind power can be used to generate electricity, either in parallel with mains supplies or for stand-alone applications with battery back-up. In order to generate worthwhile quantities of electricity, average wind speeds of more than 5-6m/s are typically required.
There are two basic kinds of turbine: horizontal axis and vertical axis. Horizontal axis turbines are generally more efficient and most commercial models are of this type. These comprise a central hub supported on a tower with (usually three) evenly spaced blades and rotate at an almost fixed rate, regardless of wind speed. Vertical axis systems can be installed without the need for a tower, and may be easier to integrate with a building’s structure. Minimum speeds of 3.5-5.0m/s are required to allow most turbines to cut-in and turbines include power regulating devices which operate when wind speeds exceed a safe limit.
The best locations for wind turbines are away from obstructions which affect air flow, including any features of buildings which may have an effect on airflow. Wind speed increases with height and so turbines often require masts or towers to take advantage of higher wind speeds and to avoid turbulence caused by the building structure. Ideal geographical locations include near hill tops and the coast.
Wind characteristics are specific to each location and initial evaluations of the feasibility of wind power at any particular site will require details of historic meteorological data. Wind power is more viable where night generation can be used or electricity can be sold back to the grid.
Due to the generally windy climate, the UK is well positioned to exploit wind energy.
Please get in touch if Callidus Design can be of assistance with the design of your new wind turbine installation.
(extracted from CIBSE TM38 – Renewable energy sources for buildings)