The SolvisStrato stratified buffer tank is specially designed for use in solar systems. It is the core of the Solvis large thermal systems with collector surface areas larger than 15 m² and may be used universally: for solar heating of drinking water, for solar coverage of heat losses in swimming pools, for solar systems with supplemental heating support and in heating systems using condensing technology or district heating for optimal utilization of low return temperatures. The SolvisStrato stratified buffer tank is an energy-optimized storage tank: To begin with, it provides for excellent tank stratification. Further, it distinguishes itself through its minimal heat losses because of the closed 110 mm thick insulating jacket.