Hydropower Information >> General Information >> Pumped Storage Database An introduction to Pumped Storage Power Generation, by Hiroshi Tanaka. What is the sustainable energy to be conveyed to the next generation The biggest threat to the future of mankind is the greenhouse effect on the earth. The emission from growing power generation casts gloomy shadow to the future of mankind. As most of the environmental impact today is coming from power generation, we have to seek for environmentally friendly and economical generating sources to disperse the gloom. From this viewpoint, hydropower and nuclear power are the most favorite generating sources. Geothermal, solar and wind power are the next. Electric power generation should be categorized in two parts. One is for base load and the other is for peak load. The generating sources for the base load should be environmentally friendly, economical and capable of mass generation considering the enormous quantity of energy now mankind is consuming. Meanwhile, the generation for the peak load should be a flexible one in maneuverability and be able to provide the flexible power in a sufficient amount to cope with the big load fluctuation. For the base load generator, fossil fuel thermal generations are currently used prevalently for their capability of mass generation but, from the viewpoint of emission, they are outrageous. For the least emission, large hydropower is the best choice. However, it is now criticized for its impact on local ecosystem or climate as well as on social impact on local community. The second choice is nuclear power. It is an excellent generating measure with respect to emission but the problem of disposal of radioactive waste and the risk of contamination of radioactive substance in an accident are seriously concerned by the public. The former problem with hydropower can be overcome by thorough precautionary measures based on preliminary assessment on environmental impact and by detailed discussions with local community. The latter with nuclear power are mostly technical and could be overcome by carefully developed technologies and thoughtful measures, although some problems are still to be resolved. It is regrettable that some of the issues with these generating sources stem from distrust between the concerned experts and the public and they hinders the development of these generating sources. As seen in Figure 6, geothermal is another choice though its capacity is limited. Solar and wind power can be supplementary resources but they are hardly to control the output. In addition, wind power encounters now an argument for its environmental impact on scenic view or noise. Thus, solar and wind energy can never be a main stay in future generation mix. In any event, large hydropower and nuclear power are the best choice for base load generator in view of environmental impact and capability of mass generation. Regarding the peak load generator, there are many flexible sources, such as hydropower, gas thermal and various distributed generation, as well as pumped storage. However, gas thermal and some of the distributed generation are not desirable in view of emission. Then, hydropower and pumped storage are the most environmentally friendly peak generators. As stated above, the combination of large hydropower and nuclear power as base generators and hydropower and pumped storage as peak generators would be the best choice in future power generation mix. Unfortunately, however, due to the objection from the public, it seems difficult to obtain public acceptance for such generation mix at present. However, effort to persuade and convince the public to accept such generation mix should be continued for the sake of future mankind. Until new alternative energy storage system which is more flexible with higher cycle efficiency is developed, pumped storage would continue to play a role as a main stay in peak generation and energy storage. SMES (Superconductive Magnetic Energy Storage) is one of the potential alternatives but it would not be possible to bring it into use within the next decade.