Using the latest technology in fisheries research often requires a reliable power supply. When practical, we utilize solar power, but some locations don’t yield themselves to extended periods of sunlight. This is the case for a Passive Integrated Transponder (PIT) tag detection system we recently installed in in a steep canyon of a Northern California watershed. For this project, we decided on a thermoelectric generator (TEG) from Global Thermoelectric. Thermoelectric generators have been available for years and have been used to power telecommunications on remote mountaintops and even spacecraft, but their application in fisheries is just beginning. The technology (see video) utilizes a temperature gradient between semiconductor materials to create direct current (DC) electricity. The system we are using runs on propane or natural gas and can be configured to produce between 6 and 48 volts. Because there are no moving parts, the TEG requires little maintenance and the DC electricity produces little electronic noise, which can be problematic for PIT tag systems. The only real limitation to this system is keeping the TEG supplied with gas, but with consumption at 1.5 gallons of propane per day a 250 gallon tank can last nearly 6 months.