How many windfarms are need to supply 75 of the power in USA?

Answer 1

A modern wind turbine can produce around 2.5 MW. That is under optimum wind conditions. It will produce substantially less at lower wind speeds.

I know of one wind farm that has never produced more than 90% of its theoretical capacity.

In 2005, the net generating capacity in the US was 978 GW. For easy math, let's round this up to 1000 GW. 75% would be 750 GW.

750 GW = 750,000 MW

750,000 MW ÷ 2.5 MW / wind turbine = 300,000 wind turbines.

The typical wind farm is between 50 and 100 wind turbines. Let's use an average of 75.

300,000 wind turbines ÷ 75 wind turbines per wind farm = 4000 wind farms.

Answer 2

no more than 5 - 10 percent of the connected load could ever be supplied by wind energy. even the windiest spots have calm days. could you do without electricity for a couple of days waiting on the wind to pick up? the grid has to be 100 percent reliable. wind can help as a substitute for other less efficient sources when available. Also it will take more than windfarms to make a dent in the electric demand. Areas that have suitable wind characteristics, Wyoming for example, are not connected with sufficient HV transmission lines to transport the electricity to markets that have a need.