Recommended:

1.    M. Ragheb, “Energy Storage and Transport Systems, Bridging the Supply-Demand Gap,” Lecture Notes, Web Text, 2011.
2.    Yves Brunet, "Energy Storage," J. Wiley and Sons Inc., 2011.
3.    Bent Sorensen, "Renewable Energy Conversion, Transmission and Storage," Academic Press, 2007.
4.    J. A. Duffie and W. A. Beckman, "Solar Energy Thermal Processes," Wiley-Interscience, 1974.
5.    D. Linden and T. B. Reddy, "Handbook of Batteries,' McGraw-Hill Professional, 2001.
6.    A. Luque and S. Hegedus, "Handbook of Photovoltaic Science and Engineering," Wiley and Sons, 2003.
7.    M. V. C. Sastri, "Metal Hydrides: Fundamentals and Applications," Springer Verlag, 1999.