WSE Uniwave - Oscillating Water Column (OWC) Technologies
The Wave Swell Energy (WSE) technology is based on the well-established concept of the oscillating water column (OWC). The OWC is an artificial blowhole consisting of a chamber that is open underneath the waterline. As waves pass the OWC, the water rises and falls inside, forcing the air to pass by a turbine at the top of the chamber. This turbine generates electricity.
Previous OWC technologies have all been bidirectional. The WSE technology, however, operates unidirectionally. This results in the WSE turbine being simpler, more robust and reliable, and exhibiting a higher energy conversion efficiency. The only moving parts in the technology are the turbine and bespoke valves, all of which are well above the water line. There are no moving parts in or below the water.
Base load power is electrical power which can be produced constantly and to a prescribed minimum (or base) load.
Base load power is typically produced by coal or gas fired power stations which can store the fuel to be used on demand. Renewable energy is typically not considered base load power as, without an adequate storage capacity, the intermittency of the resource precludes the constant production of a given base load of that power.
Ideally, traditional base load sources would be used to complement the intermittency of renewables, that is ‘filling in the gaps’ when the renewable source is unable to meet the minimum demand. Unfortunately, traditional base load sources of power must overcome a level of inertia – it typically takes hours to increase or wind back production. Wind and solar energy production can vary on time scales that are significantly shorter than the time scales of coal and gas fired power variability (which is also true of other sources such as nuclear). This results in a temporary shortage or surplus of energy.
Wave energy as a resource, however, varies much more slowly than wind or solar power. It is also highly predictable over periods of several days. Therefore, wave power is considered complementary base load power. It can be used in conjunction with traditional base load sources to provide a constant output to satisfy demand, with a seamless transition between the renewable and fossil fuel sources. For example, as waves increase in size producing more energy, a coal fired power station can gradually scale back its production, and vice versa.
- Most previous wave energy technologies have been developed for deep water applications, requiring floating units. Floating objects are inherently less efficient at absorbing the energy in waves. And, in almost all cases, these technologies have been reliant on moving parts in the water, which have often been their downfall. Having moving parts in the water results in prohibitively high maintenance costs, particularly when the technology is located in deep water. The WSE technology involves no moving parts in the water. The only moving parts – the turbine and the simple flap valves – are located well above the water line. In addition, the technology involves no oils, lubricants or contaminants.
- More closely related to the WSE technology, though, is the class of technologies known as oscillating water columns (OWCs). All previous OWC technologies have been bidirectional, requiring air turbines that operate on reversing flow. This necessitates either an inefficient turbine, a more complex turbine with pitching blades, or a complicated system requiring the redirection of flow on each cycle. The WSE technology, however, is fundamentally different in that it utilises unidirectional flow allowing for a simpler, more robust, more efficient and cheaper air turbine.
Our short to medium term focus is project opportunities where WSE technology can provide immediate solutions. Such projects relate to displacing expensive diesel in remote locations around the globe, while also helping to alleviate coastal erosion with the strategic placement of WSE units.
WSE has the only renewable energy technology that doubles as a form of coastal protection. WSE units, when deployed in close proximity to each other, act as a breakwater or sea wall, protecting the coastline from erosion, mitigating the effects of climate change, and generating revenue from electricity produced.
Longer term, we expect to provide large scale grid connected electricity. Waves are a highly predictable, reliable and infinite resource. We aim to make wave energy a complementary base load power source that provides a meaningful contribution to the global energy mix.
Further applications of the WSE technology include:
- Large scale grid connected electricity
- Generation of electricity in remote locations (including islands), displacing expensive diesel
- Coastal protection and breakwaters – the units placed side by side act as a breakwater
- Desalination – the production of potable drinking water
- Hydrogen production.
Coastal protection – WSE technology applicationsCoastal erosion is an increasing problem in many parts of the world, with the intensity of wave action on shorelines being enhanced by climate change.
The traditional way to deal with this issue is to install breakwaters, sea walls, and groynes, in order to reduce the level of wave energy that makes it to shore. This requires a significant capital outlay which is a ‘sunk cost’.
The Wave Swell Energy (WSE) technology provides a cost effective solution to the problem of coastal erosion. WSE units, when deployed in close proximity to each other, act as a breakwater or sea wall. This not only protects the coastline from erosion but also generates an annuity style revenue stream from the electricity generated.
The US Department of Energy website, Tethys, has published reference to a study that concluded “The results highlight that wave farms are able to decrease beach erosion (shoreline retreat) even under sea-level rise scenarios. That makes wave farms attractive management strategies, as they contribute to the decarbonisation of the energy mix and are more efficient in terms of coastal protection under sea-level rise than traditional hard-engineering structures”.
WSE units can be placed next to each other in a line with no gaps, effectively producing a breakwater that can block up to 100% of the wave action from the coast while converting that energy into electricity.