Micro wind turbine performance under real weather conditions in urban environment

The aim of this article is to evaluate the performance of micro wind turbines in a built-up environment. For this purpose, five independent micro wind turbine systems, consisting of two distinctly different models, were tested and evaluated under real life conditions over a period of 12 months. This article provides an overview of the experimental set-up used to test the two different micro wind turbines and then goes on to present the basic background theory for horizontal axis micro wind turbines and the variation of coefficient of performance with wind speed. The wind potentials at the test site were assessed to determine the theoretical outputs of the turbines which were compared with the measured outputs over a year. The measured outputs were disappointingly low. One reason for this is turbulence, for which directional turbulence (lateral turbulence) has been shown to be a key indicator, better than the standard wind speed (longitudinal) turbulence. Another factor is the inverter efficiency and power consumption, which is not negligible. Finally the theoretical paybacks under the 2010 Feed-in Tariffs were calculated along with estimated carbon savings. Practical application: Renewables such as wind turbines are increasingly being designed and installed to help achieve lower carbon buildings. The output of micro turbines, however, can be disappointing due to lateral turbulence and inverter consumptions. These factors are explained so that designers can be aware and assess the likely outputs more accurately.