Is a windmills a nonrenewable resources or a renewable sources?

Answer 1

It would be naïve to say that there is a completely renewable source of energy. The sun, for example, which is the source of all energy on Earth, will form a Red Giant in a few billion years time, and will produce far less energy than it had in the past. Additionally, although wind (which relies on the sun) is renewable per say, machines to make use of wind energy, such as wind turbines, require maintenance et cetera and are in that sense, not *completely* renewable. However, for our purposes, and especially in contrast to Fossil fuels, the Sun, the wind, the tides et cetera are renewable sources of energy. Windmills are machines which convert the wind's energy into another form of energy. They, themselves, are not "renewable *sources," rather they can make use of a 'renewable' source, 'the wind,' to transform kinetic into potential energy.