Wave Power Developments
There are several wave power developments that are now being scaled up to generate reliable and clean energy from an abundant and sustainable resource – waves from the sea. The Commonwealth Scientific and Industrial Research Organisation (CSIRO) estimates that wave energy is at least three times more predictable than wind energy. There are great opportunities to expand, and benefit from, wave power that is a reliable source of energy. With almost half of the world’s population living within 100 kilometres of the coastline there will always be a market for clean energy generated by the sea.
This month three examples of different approaches to wave energy converters are showcased from around the world. They are all pioneering the generation of electricity from the waves. Each one utilises a slightly different approach to capturing energy from the waves and each has a different electrical output. The solutions are quite small but are being scaled up and offer good sources of energy for islands. It can remove the need for fossil fuel generators that are typically powered by diesel.
In Tasmania, Wave Swell is installing a 200kW wave energy device, to be deployed on King Island by the end of 2020. Construction of the device is almost complete, with the unit commissioning expected to begin in the first quarter of 2021. The energy produced will complement existing wind and solar grid, diversifying the renewable sources. It has the benefit of reducing diesel consumption on King Island.
This device uses well-established concept of the oscillating water column (OWC). As water rises and falls inside, air is forced past a turbine at the top of the chamber. The turbine generates electricity which then can be sent back to shore via a cable. The technology operates unidirectionally. This means that the turbine is simpler, than models that operate bidirectionally, more robust and reliable. It exhibits a higher energy conversion efficiency as a result. Details can be seen here: Wave Swell.
Wavestar is a Danish project, dating from 2000, that is looking to harness the power of the waves but also to create a flexible platform that will enable the combination of renewable energy sources. For example, wave power with wind power or with solar panels. Wavestar is requesting European Union (EU) support through its Horizon 2020 program which is aiming for innovation lead sustainable growth. Wavestar, as part of an industrial consortium, is aiming to produce the first full-scale 1 MW Wavestar wave energy converter (WEC) to be tested commercially.
A WEC prototype has been in use at Nissum Bredning in North West Denmark. It creates a regular output of energy from ocean swells and waves (which are typically 5-10 seconds apart). This was achieved with a row of half-submerged buoys, which rise and fall in turn as the wave passes. The design allows energy to be continually produced, despite the periodic nature of waves. There is a built-in protection system that prevents the wave machine being damaged in extreme storms or weather events.
A test 600 kW machine was installed at Hanstholm in September 2009 and has been connected to the grid since February 2010. This is a half scale machine, developed over time, which has been gradually scaled up from smaller prototypes. Designs have evolved to reduce cost and allow deployment to other sea areas. It is estimated that the machine should be adaptable to different types of wave systems around the European coastline. This is a key feature that should allow the technology to adapt and expand. It aims to be a scalable low carbon energy solution for the future.
The final example is another wave power project benefiting from the EU Horizon 2020 program: Arrecife Systems from Spain. Prototypes have been tested in the north of the country in the Cantabrian Sea. It is another company that is developing small energy systems that will support different situations. An example is providing power to small island communities. It has a 75kW, 440kW and 2MW system. The wave energy converters are designed to work with the most common waves, ranging in height from 1 to 5 metres. This represents around 98% of the waves. As a result, there is more efficiency both in the manufacturing and in the energy production which allows the WECs to be working at full capacity during more hours of the day.
These examples show the potential to scale up wave technology and harness energy from the sea which is very reliable and clean source of electric power. The energy being generated is gradually being developed with the different designs are being tested fully to evaluate and improve them. Capturing continual energy will be a big win over solar and wind power. Wave power has a huge potential if it is given the right backing for it to grow and prosper.