The air, water and soil pollution caused by these plants in terms of fly ash, CO2, SO2, NO2 and particulates etc. is becoming unacceptable in the environmentally conscious society.
Hydro-electric power generation is associated with displacement and resettlement of human population from the site of hydel plant to other places. This leads to considerable human problems causing considerable delay in the implementation of the project and escalation of its cost. New dams built may affect the ecosystem of the locating sites.
Radioactive pollutants released form nuclear power plants are chronically hazardous. The commissioning of boiling water power reactors (BWRS) have resulted in the critical accumulation of large number of long lived radionuclides in water. Environmentalists argue that thermal effluents from nuclear reactors have acutely affected the aquatic eco system. The dangerous radioactive waste cannot be buried in land without the risk of polluting soil and under ground water. Several well publicised accidents (Ex. Chernobyl disaster at former U.S.S.R.) and radiation episodes have given a lot of fear in the mind of general public regarding the radiation hazards.
The use of solar energy, from the environmental viewpoint, is a completely safe operation. However, the sites for larger installations of solar power plants should be selected without reducing the forest cover. Cadmium, used in fabricating thin film solar cells, is both poisonous and a possible carcinogen. Carbon dioxide produced while forming silicon from silica may increase the atmospheric temperature causing green house effect. Silicon dust is also an important occupational hazard.
The burning of coal, oil, wood, dung cakes and petroleum products would cause environmental problems. (1)The increase in CO2 concentration is largely responsible for green house effect and global warming, while (2) disposal of fly ash requires large ash ponds and may pose a severe problem (3)The smoke produced by burning of wood, agricultural by-products or animal's dung cake causes respiratory and digestive problems and may also lead to eye and lung diseases. (4) Nitrous oxide, Sulphur di-oxide and CO2 can cause acid rain.