Solar-Plus -Storage, which at the present day is already economical viable in most of the markets, but specially where Diesel an HFO is used as primary fuel. Energy storage is the capture of energy produced at one time for use later. A device that stores energy is generally called an accumulator or battery. Energy storage involves converting energy from forms that are impossible to store to more economically and viable storable forms. The most common used type of energy storage is the rechargeable battery, normally Lithium-ion, but other new forms are becoming economically viable.