Wave Swell Energy Ltd (WSE) is an unlisted Australian public company. The company has developed a world leading proprietary technology that converts the energy in ocean waves into clean and emissions free electricity. This electricity can be transmitted to shore and into the grid, or used to power an onboard or shoreline located desalination facility.
Wave Swell Energy is currently developing a 1 MW wave energy project that is intended to be installed in the ocean off the west coast of King Island, between Tasmania and the Australian mainland. The aim of the project is to demonstrate the ability of the company's technology, when installed at large scale, to produce electrical energy at a cost comparable to that of new coal-fired power plants. WSE is collaborating with Hydro Tasmania and the King Island Council and community to ensure the project is developed to be of benefit to all stakeholders.
While Wave Swell Energy is a recently established company, many elements of its technology have been developed over a period of more than a quarter of a century. The inventor of the company's technology, Dr Tom Denniss, first proposed an earlier version of the technology in late 1990.
After inventing the initial technology, Dr Denniss oversaw the ongoing R&D program and subsequent construction of the first full scale ocean based prototype of the technology.
The technology of Wave Swell Energy is based on the well-established concept of the oscillating water column (OWC). An OWC is effectively an artificial blowhole. It is a large hollow concrete chamber, partially submerged and sitting on the seabed, and vented to the ocean through an underwater opening. The chamber also includes a small opening to the atmosphere above the water line, in which is housed an air turbine.
As wave crests and troughs pass the OWC, water enters and leaves the chamber through its submerged opening. This water rises and falls inside the chamber, causing the pressure of the air trapped above to oscillate between positive and negative pressure. These pressure fluctuations force the air to pass by a turbine at the top of the chamber, generating electricity as it does so.
The fundamental difference between the Wave Swell Energy OWC technology and that of other companies is that, via an ingenious conceptual difference, proprietary to the company, the WSE turbine is only exposed to air flow from one direction. This results in a much simpler turbine design, which is also more robust, more reliable, and at the same time exhibiting a higher energy conversion efficiency.
The only moving parts in the entire technology are the turbine and some simple off-the-shelf valves, all of which are well above the water line. There are no moving parts in or below the water. This means maintenance is only ever required to be performed on the easy-to-access regions well above the ocean.
Connected to the WSE turbine is an off-the-shelf generator, chosen for its compatibility with local grid requirements. Electricity is generated at whatever frequency and voltage is required for easy transmission into the grid.
The standard Wave Swell Energy OWC produces a peak power output of 1 MW. While moment to moment output is quite stable and constant, longer term variations in output occur as wave heights and periods change with weather conditions.
A secondary product of the WSE technology is desalinated water. The power produced by the OWC can be used to operate an onboard or shore-based standard reverse osmosis plant. Alternatively, a pressure accumulator can be included as an intrinsic part of the OWC to directly drive the reverse osmosis process, resulting in a decrease in pumping overheads and an increase in overall process efficiency.
The company hopes to see projects on the scale of 100 MW or more up and running within the next five years.
Source and images: Wave Swell Energy Ltd
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