Water Horse takes test race down Tanana River in Alaska

Researchers from the Alaska Center for Energy and Power (ACEP) have tested the second iteration of Renerge’s Water Horse hydrokinetic energy harvester on Tanana River in Alaska.

Based on marine hydrokinetic technology developed by Renerge, the Water Horse prototype converts river currents into electrical energy by harnessing forces developed by vortex shedding off a submerged bluff body.

The bluff body oscillates up and down in the current and the system converts this motion into electricity through a power take-off (PTO) mechanism and generator.

During the latest test campaign, ACEP researchers examined the performance of a dual oscillator system, with bluff bodies positioned upstream and downstream to investigate the effects of wake off the upstream bluff body on the performance of the downstream system.

The testing of the prototype’s second iteration took place for ten days at the Tanana River Test Site in Nenana.

According to ACEP, the device’s mechanical suspension, spring and PTO systems were improved from the first prototype tested in 2020.

An electronic power converter system was also implemented and tested to convert the power pulses from the water horse into usable DC power.

Data collected from field testing will be analysed to quantify the system power curve and efficiency, and estimate the levelized cost of energy (LCOE) achievable with the Water Horse approach, ACEP said.

The testing has been supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy.