Bradford White. EcoStor SC hot water storage tanks are optimized for use with most solar water heating collector systems. For maximum efficiency, the units’ heating elements activate only when solar energy does not satisfy demand. The tanks feature an internal single-wall heat exchanger, dual 5,500-watt or single 4,500-watt backup heating elements, glass-lined carbon steel heat exchanger cells and linings, foam insulation, and dual aluminum anodes for extra-long service life. Three tank models with 60- to 115-gallon capacities are available. 800.523.2931.