Exploring the complementary relationship between solar and hydro energy harvesting for self-powered water monitoring in low-light conditions

Relying on solar energy alone to power water monitoring stations limits the ability to monitor water resources in low-light locations, such as for streams with dense tree canopy cover. To address this limitation, water monitoring stations could have a supplementary micro hydro-turbine to harvest kinetic energy from streamflow. To explore this possibility, we simulated the energy harvesting potential at 42 locations with long term stream velocity records and determined the canopy cover for streams across the contiguous United States (CONUS). Results show that a site with typical streamflow velocity and dense evergreen tree canopy would have 1.6 times less sample loss, from 68% to 43%, after adding hydro energy harvesters. Many streams across the CONUS with dense canopy cover could benefit from this, especially headwater streams and streams in the Southeastern US where many watersheds have more than 50% of their stream length under dense tree canopy cover.