June 23, 2008:  Large, electricity generating, wind mills screw up radar reception, and that is putting many wind farm (groups of electricity producing windmills) plans on hold.  Wind farms are becoming a cost effective way to create electricity, partly because of improvements in technology, but largely because of the rising price of oil. In the next few years, wind will be cheaper than coal or oil, and quicker to get on line than nuclear. While wind only produces about one percent of U.S. electricity now, that could rise to 20 percent or more in the next 25 years. But first, the elderly radars that equip the air traffic control system in the United States will have to be replaced. The government has resisted doing so, because of the expense, and the risk of screwing it up (always a bog possibility for projects like this, and really bad news for politicians.)

More modern radars use software and faster processing power that filter out the interference generated by those swirling metal windmill blades. Most military radars are already equipped to do that, but that's because ships and aircraft are so likely to encounter these windmills, wither offshore, on ridge lines or on the Great Plains of the American Midwest.