Highly novel mechanisms for harnessing the energy of naturally-flowing water ways such as streams, rivers, tidal flows and deep ocean currents. Potentially scale-able to Megawatts.
Above: Early TWH generator prototypes tested in a tow-tank.
Wind turbines do not encounter trees, rope and even shipping containers flying at them through the air, except perhaps during tornadoes. Naturally flowing waterways however are vast drains sweeping all manner of debris from the planet's surface. So it has been challenging to apply the spinning-blade approach that works so well for wind turbines to harnessing un-dammed waterways. Pliant Energy Systems has taken a completely new approach to harvesting the vast un-tapped energy coursing through the world's streams and rivers without the need for expensive and environmentally damaging dams. Key features of the company's TWH generator technology are:
- Deflects heavy objects, resists entanglement
- High survivability and resilience
- Low secondary structure costs
- Low installation costs
- Easy retrieval and re-deployment for lower maintenance costs
- Animal and human safety
- Effective in shallow or slow-moving water
Above: The TWH generator can be fished from the water for electrical and mechanical de-coupling in air.
Below: Bladed turbine generators require divers and/or ROVs for difficult underwater coupling and de-coupling.
Below: Diagramatic comparison of a conventional bladed system on a mast (left) with a TWH generator (right) which is safe for aquatic animals and human recreational activities, and which will yield rather than break when struck by an object in the water flow.
Instead of spinning, the TWH generator undulates to create torque in its core region. Where the river bed is soft, the generator is attached via a flexible stem to a stake driven into the river bed. For rocky rivers, the generator can be attached via a tether to a dead-weight dropped into the water. The weight does not need to site level to be effective so no civil engineering is required.
Below: Comparison of a Pliant Energy Systems TWH generator with a conventional bladed turbine system attached to the piers of a highway overpass. The TWH generator requires only a tether attachment whereas the bladed system requires an expensive and rigid secondary structure to hold it in place. Logs, branches and other debris in the water current will destroy or clog the bladed system. The TWH generator's flexible fronds and undulating motion will allow it to shed debris and yield harmlessly when impacted by heavy objects.