New designs in windmills make them more efficient. They do not take up a great deal of land. It is a very clean process. The initial costs of a wind farm are about half the cost of a nuclear power plant that produces the same amount of energy. Though the feasibility of using solar energy is constrained by location, weather and time of year in many parts of the world solar energy is a competitive resource.
Solar energy is used efficiently in water heating and in space heating of buildings.
When heating water a collector is located on the outside of the building and when the collector is warmer than the water in the tank the water is circulated, heated, and stored for later use. There are two ways to heat the buildings themselves passive and active solar heating. Passive heating contains no mechanical components and basically consists of large windows with walls or floors that absorb the release the energy of the sun. An active heating system consists of an outside solar collector and a heat storage tank from which the heat is fanned through ducts throughout the building. Solar energy can also be harnessed for industrial use.