This heat and evaporated water flow out the top of the tower is in the form of a fine cloud-like mist. The cooled water is collected at the bottom of the tower and pumped back into the plant for reuse. Although there are many similarities between them, there are some important differences that affect how each plant uses water. In fossil fuel plants, coal, natural gas, or oil are burned to provide the heat necessary to turn the water into steam. Biomass or solid waste fuel types are included with fossil fuels.
Water is required to take care of the ash waste created during combustion.
In nuclear plants, water is not required for ash disposal but is needed to keep the nuclear material from overheating and melting. Power generation is measured in watt-hours, which is an electrical energy unit of measure equal to one watt of power supplied to, or taken from, an electrical circuit steadily for one hour. The power-generation values also are collected for quality assurance. Individual facilities also are an important source of information. Individual thermoelectric power generating facilities are frequently owned or managed by large utility companies.