The growth of the marine energy sector comprising wave and tidal energy is poised at a stage that the wind energy sector found itself 10-15 years ago, although it is predicted that the marine energy sector is set to grow faster. The wind sector has come a long way since then. Receiving government support, financial investment and technological advancement, it is currently the most mature renewable energy sector. The same is needed to see the marine energy sector reach commercialisation as well.

A Global Resource: Europe Remains A Leader

Wave energy sources are not only available in plenty but are also consistent, predictable and have the highest energy density among all renewable energy sources. The best resource is found between 40 - 60 degrees of latitude where the available resource is 30 to 70 kW/m, with peaks of 100 kW/m. The potential worldwide wave energy contribution to the electricity market is estimated to be of the order of 2,000 TWh/year, about 10% of the world electricity consumption.

Wave energy technology is being developed in a number of countries such as Canada, China, Chile, India, Japan, Russia and the US, however, Europe is leading the way in innovative technologies, pilot projects as well as pushing the existing technologies towards commercialisation including countries such as  UK, Ireland, Portugal, Norway and Spain. In tidal energy, Canada, Argentina, Western Australia and Korea possess the resources but here again Europe is a frontrunner, with the UK and France seemingly promising.

The UK – having some of the best wave resource in the world, as shows in Figure 1 below - is targeting 40% of its energy from renewables by 2050 of which 20% is to be sourced from wave and tidal energy. The UK is estimated to possess the capacity to generate approximately 87TWh of wave power annually equivalent to 25% of current UK demand. The UK has committed GBP 25m since 1999 towards the wave and tidal programme. 

Focus Remains On Technology (Wave Energy)

Wave energy devices can be divided into three main categories: shore-line devices, near-shore devices and offshore devices. Shore-line devices are devices on the shore, near-shore devices are ones that are within 12-25 miles off the shore and offshore devices are ones that are placed in waters of more than 50 metres in depth and/or more than 25 miles from the shore.

There are around 1000 patents for wave energy converters currently in the market and broadly fall under the above-mentioned categories. To mention a few examples, under shore-line devices are two well-known technologies known as the Oscillating Water Column (OWC) and the Seawave Slot-Cone Converter (SSG). An example of the former is the Land Installed Marine Powered Energy Transformer (LIMPET) installed by Scottish wave energy developer Wavegen, on the island of Islay in Scotland. According to the company, the current Limpet device – Limpet 500 – was installed in 2000 and produces power for the national grid. A prototype of the latter i.e. SSG is being developed by Norwegian wave energy technology developer WAVEenergy AS and its partners. The device can be installed both on the shore-line and offshore.
One of the companies involved in near shore-line devices, Wave Energy SA in Greece is developing the Wave Energy Point Absorber. Having completed full scale tests in depths of 10-20 metres it is now planning on placing the devices in greater depths. The other is Finnish company AW Energy Oy with the WaveRoller device. Having undergone numerous tests at the European Marine Energy Centre at Orkney in Scotland (EMEC) and Ecuador, the company is now planning a pilot plant of 1MW capacity in 2007 to demonstrate the full size system performance.

In the offshore devices category, two examples are the AquabuOY and Pelamis. Canadian renewable energy company Finavera Renewables is planning on building a 100MW offshore wave energy project using the AquabuOY technology, in Figueira de Foz off the coast of Portugal, beginning with a 2MW demonstration plant. It is also planning projects in the US, Canada and South Africa. Edinburgh-based wave energy technology developer Pelamis WAVE Power (formerly Ocean Power Delivery) is in assembly phase of its patented Pelamis wave energy converter device being undertaken at EMEC, after which it will undergo sea trials and then be commissioned off the coast of Portugal.

With so many technologies around there is no clear consensus on which technology will prevail over the others or which ones will be successful.

A Look At Tidal Energy

The first tidal energy project was a 240MW plant in the Rance estuary, near Mont Saint-Michel in France. The amplitude between the low and high tide is one of the highest in the world as well as the speed with which the water comes into the estuary, making it an ideal site to build a tidal energy project. The project has been running since 1967 generating 600 million kWh annually. There are other projects in Canada, Russia and China as well.

The technology on which tidal energy projects are based is very similar to hydro projects where a dam or a barrage is constructed across an estuary entrance. The major challenges that face this sector are the high capital cost and long construction times as against low operating costs.

The Future: Europe At The Forefront Of Research
 
There are two main research centres in Europe focusing on the development and commercialization of ocean energy technologies. The first is the European Marine Energy Centre located in Orkney in Scotland. Most importantly, it provides developers with sites to test their prototypes. Government and other public sector organisations have invested around GBP 15 million in the creation of the centre and its two marine laboratories. The other is the Wave Energy Centre in Portugal. It provides strategic and technical support to companies, R&D institutions and public organizations. It also looks for international cooperation helping foreign companies test their devices in Portuguese waters.

The marine energy industry has a long way to go but ongoing research and government support should lead to improvements making these technologies more economically attractive in the future. Combined with intensifying company activity in this field, Europe is poised to be the place to watch in the marine energy arena of the future.

Gouri Nambudripad is Research Analyst, Energy and Power
Systems Group at Frost & Sullivan, in London. If you would like more
information about our Green Energy subscription and related research, send an
e-mail to Chiara Carella - Corporate Communications, at
chiara.carella@frost.com with the following information: full name, company
name, title, telephone number, e-mail address, city, state and country.
Requested information will be sent by email upon receipt of this
information.