Alternative energy sources are renewable and are commonly called free energy sources. There are many alternative energy sources such as hydroelectricity, solar energy, wind energy, biomass and geothermal energy. Using alternative sources is more expensive in the long term, but is a much safer option for our environment than fossil fuels. While everything used is completely free, such as water and wind, the equipment used to generate these things is expensive. There are several pros and cons that come with using alternative energy sources. Alternative energy does not focus on the burning of fuel, nor on the nuclear process. Alternative energy is basically an alternative to fossil fuels. Fossil fuels include coal, oil, or even natural gas. One day coal and oil will run out, and their cost will become higher and higher day by day. We can reuse alternative energy, but no matter what energy sources we use, there will always be pros and cons. Hydroelectric energy is one of many examples of an alternative energy source. Hydroelectricity produces energy by moving. Wind energy is another form of solar energy. Wind is not only a clean fuel source, but it is one of the cheapest alternative energy sources. Just as the wind continues to blow and the sun shines, wind energy can produce energy to send to many different areas. There are not many locations that have continuous wind. And for this reason the widespread development of wind energy is not as great as it could be. While there are more advantages than disadvantages when it comes to this energy source, the disadvantages should be taken just as seriously. Wind energy can harm animals, there was a study that birds came into contact with the turbines and died. For many people the noise from the turbines is unbearable and is another thing that must be taken into account