Due to the development of a high-technology-society, power demand has been increasing year after year. A big problem under such an environment is the big difference of the electric demand between day and night, and also throughout the seasons. It is getting difficult to construct power stations and transmission facilities which cover peak power demands not only from the point of construction cost but also conservation of resources. If we succeed to reduce these fluctuations, we can contribute to efficient operation at power stations, decrease of operation cost, and conservation of resources.
It is an alarming fact that today - in the 21st century - there are still billions of people without access to electricity or clean cooking facilities. The ambitious goals that have been set to eradicate extreme poverty can never be fully realised without acknowledging and confronting this fact.
Today, there are 1.4 billion people around the world that lack access to electricity, some 85% of them in rural areas. 50% of family income in developing nations goes to non-renewable energy sources.
Fig: Number of people without access to electricity in rural and urban areas in the New Policies Scenario (millions)
Fig: Grid-Scale Energy Storage (billion $)