EverGen Series devices from Marlow Industries, Dallas, TX, are thermoelectric-based energy harvesters that offer a low-3cost, zero-maintenance power source for wireless sensor applications. Three devices are available: EverGen Liquid-to-Air harvests the thermal energy between a higher-temperature fluid and ambient air via natural convection for conversion to electrical power; EverGen Liquid-to-Liquid harvests the thermal energy between a higher-temperature fluid stream and a lower-temperature fluid stream; and the EverGen Solid-to-Air harvests the thermal energy between a higher-temperature solid surface and ambient air via natural convection. The devices can be used to power sensors, actuators, valve solenoids, and other small devices.