In theory, ocean current power — thermohaline currents — could be the perfect eco-energy source. Unlike solar and wind it doesn’t require expensive, giant grid-level mega-batteries to keep output consistent, which reduces its carbon footprint and the need for environmentally dubious mining. It also doesn’t cause habitat loss like solar, or impede ships like wind farms, as ocean current power is 100 m beneath the surface. What’s more, it is estimated that the Kuroshio current could provide up to 205 GW of power, which is comparable to Japan’s current total electricity production.
This is where Japan’s heavy machinery maker IHI Corp comes in. They recently completed testing of a scale prototype sub-sea turbine called Kairyu with astonishing success.
The perfect energy source? Not quite. There are three problems with this tech. Noise, turbine strikes, current slowing and climate change.