How fast does the wind speed need to be to build a utility-scale wind farm?

The industry-accepted guideline is currently between 6-6.5 metres/second to generate enough electricity to finance and build a large (i.e. 50 MW +) utility-scale wind farm. By way of example, a wind speed of 6.45 metres/second, which is classified as class 3 or “marginal” in most cases would be sufficient. Of course this depends on many other factors, the most common being the price at which the electricity if purchased and the type of wind turbine utilized. If a utility (and ultimately consumers) are will to pay a slightly higher price for clean energy, utility-scale wind farms can be feasible at 5.5 metres/second. Wind speeds are generally higher in off-shore and in coastal areas but the cost of construction is significantly higher. More efficient wind turbines capable of generating more electricity from lower wind speeds are being developed continually and the amount of electricity capable of being generated from lower wind speeds has been continually increasing over the past few years.