Designed to simplify installation, the SolPak all-inclusive active solar domestic water heating system comes with a heat exchanger tank, solar collector panels, a controller, multi-speed pump, thermal expansion tank, and other items. Collector panels are certified by the Solar Rating & Certification Committee. The maker says a SolPak system can reduce the water heating portion of energy bills by as much as 80%. 800.621.5622. www.rheem.com.