The variable speed pump is a perfect match for solar pool heating systems, especially when an automatic controller is used. Without a controller the pump can be scheduled to run at optimum solar circulation speed when solar energy is most likely to be available. Adding a controller adds the capability of changing the pump speed based on the availability and demand for solar heating. With or without solar energy, the variable speed pump will pay for itself with energy savings. You can cut pumping costs up to 90% with this great technology while getting a far quieter and longer lasting pool pump.