The EverGen small PowerStrap is a non-invasive thermal energy harvesting power assembly compatible with many existing wireless sensors on the market. The PowerStrap is an alternative to replaceable primary cell batteries and can extend existing sensor battery life beyond 10 years. These assemblies can be installed on a pipe in a horizontal or vertical orientation and from 2 to 6 inches or 6 to 14 inches pipe diameter. Installation is a five minute, non-invasive process.