An analytical model has been developed from which the basic thermal parameters of the flow through non-magmatic hot-spring systems can be calculated from data that can be obtained at their discharge: water outflow temperature, mean surface temperature, and water geochemistry. From this flow, the maximum thermal power potential of a system can be calculated. The model has been applied to Clifton Hot Springs in eastern Arizona, USA, and the potential power generation of this system was estimated to be within the range of 0.8-3 MW. The model has also been successfully applied to three hot spring systems in Colorado with different characteristics. The simple model is not thought to represent the details of flow in the aquifers, but provides a useful approximation of the temperatures and thermal power potential in the systems. (C) 2016 Elsevier Ltd. All rights reserved.