Now–a–days rechargeable batteries (Electrochemical cells) are available.These electrochemical cells are pollution free when compared to thermal power plants.
People are interested in chemical energy because we can produce electrical energy in laboratory. In the stated methods(solar power plants, thermal power plants, tidal plants, hydel plants, wind energy plants ) there is a need of large apparatus and assembly of instruments. But in case of chemical energy, small electrochemical cells are enough to produce energy.
The importance of Electrochemistry, in the history of discoveries in Physics and Chemistry, is immense, to say the least. Had it not been for the voltaic cell, where there was a controlled source of electrical charge, discoveries in electricity (and magnetism) would perhaps have been delayed. Many new metals and non–metals were isolated and collected solely because of electrolysis of compounds and solutions were possible with a voltaic cell.
The electrochemical energy conversions are used to produce long running storage batteries to use in automotive systems (refer to figure).