The development of wind turbines and wind generated electricity in the 1980s and 1990s resulted in cost reductions attributable to various innovation processes . In Denmark, the cost of installed wind turbines (i.e. cost per kW) reduced by 5% from 1980 to 1985, and by 50% over the longer period from 1980 to 2000 (Neij et al., 2003). Due to successful up-scaling and improved efficiency, the cost reduction in generated electricity was even larger, falling by 70% during the period 1980 to 2000 in the case of Danish produced wind turbines . The development of larger turbines did, however, face economic and logistical constraints. Until the mid 1990s, up-scaling was limited by the cranes available for the erection of the turbines, and the process of up-scaling with its greater use of materials challenged further cost reductions. Read more about the history wind turbines.