New England's largest wind turbine was commissioned in mid November and will be tested until the end of the winter. Students and staff from the University of Massachusetts renewables laboratory are studying the recently installed prototype ESI-80 in a ski area on Mount Tom near Holyoke. It is to provide power locally. The 300 kW turbine, upped from the model's usual rated capacity of 250 kW, is part of a three-year old project. Financial help has come from the state Division of Environmental Resources and Holyoke Gas & Electric, says Ian Baring-Gould of the renewables laboratory. Cold weather conditions typical of New England's windy ridge top areas are of particular interest as they differ from California conditions, he says. Northeast Utilities, the region's largest utility, is also donating $40,000-50,000 over the next three years to help the laboratory assess wind in western Massachusetts.