Thermal energy storage systems collect and store heat from renewable sources like solar or geothermal for later use. For example, storage of solar thermal energy involves capturing the sun's rays and using them to warm a fluid or a phase change material, which may then be used to heat a building's interior or a. Electrochemical energy storage systems use chemical energy to generate electricity. Fuel cells and batteries — particularly lithium-ion — are the most prevalent electrochemical energy storage technologies. The following are the pros and cons of using lithium. Magnetic energy storage systems, such as superconducting magnetic energy storage, store energy as a magnetic field and convert it to electrical energy as needed. These energy storage. Mechanical energy storage solutions employ water, heat or air with turbines, compressors and similar parts to capture gravitational energy or. Supercapacitorsstore energy in an electric field, rather than through a chemical process like batteries do. The following are advantages and disadvantages of using them in systems that rely.