The main advantage of wind power is that larger wind turbines have a lower per-watt cost than solar cells, provided there is wind. However, location is critical. Just as some locations lack sun for solar cells, many areas lack enough wind to make a turbine pay for itself. In the Great Plains of the United States, a 10-metre (33-foot) turbine can supply enough energy to heat and cool a well-built all-electric house. Economic use in other areas requires research, and possibly a site-survey.