**Disadvantage of Wind Energy**


**Table 1** presents global wind farms database.

### **4.3 Hydropower, water energy**

Waterfalls and fast running water flow may be used to generate electric energy. Water Energy cite is presented in **Figure 3**. Water flow kinetic energy is converted to electric energy. In the late 19th century, hydropower became a source for generating electricity. The first commercial hydroelectric power plant was built at Niagara Falls in 1879. In 1881, streetlamps in the city of Niagara Falls were powered by hydropower. Hydroelectricity can be used to store energy in the form of potential energy between two areas with different heights with pumped-storage hydroelectricity. Water is pumped uphill into cites during periods of low demand. This energy can be released to generate energy when demand is high.
