Numerical model for estimating energy generation for micro-wind turbines in the UK
2013-01-14T12:15:23Z (GMT) by
Renewable energy technologies have a large role to play in combating climate change. Wind power is the most costeffective technology for producing zero-carbon electricity, and therefore will become a leading technology to reduce human-made greenhouse gas emissions. But there is a danger for the micro-wind turbine industry that overestimates of potential power yields will disappoint installers, and damage the technology's reputation in the future. At present, the NOABL database represents the most suitable tool for estimating a site's wind speeds but it only provides an average wind speed reading for a lkm x lkm grid area within the UK. A prospective micro-wind turbine installer requires an estimation of the potential energy generation from mounting a wind turbine on their site. The wind profile for the site is largely dependent upon the surrounding terrain, and local obstructions to wind flow, so that differing sites can generate a wide range of results. It is therefore very difficult for manufacturers and installers to estimate the output for all sites. This paper presents two numerical models for estimating the potential power yield from a micro-wind turbine, for a particular site and specific micro-wind turbine. The model requires the user to take a reading from a database (NOABL) provided by the UK Government for his or her area. The wind speed is then adjusted by assessing the terrain type and installation height of the turbine. A wind speed frequency distribution is generated, that can then be matched to the chosen turbine's power curve, to estimate the annual power generated. Comparison of the results with actual power generation and weather data from a micro-wind turbine trial gives an estimate of the accuracy of the model. The results have shown that there are limitations to the accuracy of the micro-wind turbine power yield estimation model. However it does provide a potential installer with enough information to assess if a micro-wind turbine is viable. By allowing the model user to toggle with different turbines and mounting heights, the user can assess which turbine and mounting height best suits their needs. The model is of a suitable size so that it could easily be downloaded, even if further graphics were added. The model could also be an interactive web page, allowing access to the vast majority of people for annual power yields estimation for a micro-wind turbine at their site. There is also no reason that the model couldn't be extended to incorporate medium and possibly even large-scale wind turbines although noise and flicker advice would need to be incorporated. This paper was initially presented at IEMA's Knowledge Exchange Event in Oxford, in January 2009.