Wave energy

The most energetic waves are found in the Pacific and the Atlantic Ocean between the latitudes 40 and 65. The energy transported by the waves are in this region between 50 and 100 kW/m. In tropical regions this number is usually from 10 to 20 kW/m. In northern areas, the waves are more intensive during winter.

At the Norwegian coast the level of energy transport is at 20-30 kW/m, and up to 40 kW/m for the coastline from Stad to Lofoten. The theoretical potential can be calculated to approximately 400 TWh/year.

When the wind energy over the sea is transformed to wave energy, the energy density is increased. The energy density is approximately five times greater that with wind energy, if you count the energy transport per vertical area. This gives high hopes for the future in wave energy.

Research, development and industry
Pioneer work was carried out in the 80′s, especially in Japan, Great Britain, Norway and Sweden. An overview of the Norwegian work from this time can be found in White Paper nr 65 (1981-82) from the Norwegian Storting, and in a review paper from 1993. In Japan, navigation buys have been utilizing wave energy for more than 40 years. The British work has resulted in wave power plants like Pelamis. The AquaBouy is built on Swedish research from the 80′s. Lately the investigation has started up in more countries, like Denmark, India, China and Portugal.

Many different concepts for wave energy harvesting have been suggested. Over the last ten years there has been more commercial focus, and some of the largest energy companies in Europe have invested in wave energy projects. Many countries offer stimulating economic conditions, and more test facilities for wave energy have been established, for example at the Orkneys, in Great Britainand in Portugal.

Model of point absorber for wave energy developed in Trondheim. Image: Johannes Falnes

Research at NTNU and SINTEF
From 1973 Kjell Budal established a group for wave energy research in the Physics Department of NTNU, and SINTEF also got involved. The wave laboratories of NTNU came to good use in the testing of various models. Among the models tested were the concept from Kværner Brug, installed in Øygarden in 1985. Another test plant was built in the same place, based on the tapered channel concept, developed in cooperation with at predecessor of SINTEF.

After the oil crisis in the 80′s, the energy prices fell and the funding for wave energy research were reduced. The Norwegian development stalled, but some activity has now been reestablished. After 2003 we have wave energy research at the NTNU-connected institutions CeSOS as well as in various departments connected to construction, power engineering, energy engineering and industrial economy.

More information
Wave energy research at the Department of Physics, NTNU
Marine and Maritime Research – Strategic area at NTNU
Department of Marine Technology, NTNU
CeSOS – Centre for Ships and Ocean Structures, NTNU

International Network on Offshore Renewable Energy (INORE)
WaveTrain – Wave Energy Centre
Ocean Power Delivery – The world’s first commercial wave power park

IEA – Ocean Energy Systems – International Energy Agency
European Ocean Energy Association (EU-OEA) – Europa
OREG – Canada
AWATEA – New Zealand
OREC – USA

Contacts
Asscociate prof. Øivind A. Arntsen, NTNU/Construction
Chief engineer Ivar Fylling, SINTEF/MARINTEK
PhD candidate Jørgen Hals, NTNU/CeSOS
Chief engineer Karl Erik Kaasen, SINTEF/MARINTEK
Chief engineer Per Magne Lillebekken, NTNU/Physics
PhD candidate Nicolai Løvdal, NTNU/Industrial economy
Professor Torgeir Moan, NTNU/CeSOS
Professor Torbjørn Nielsen, NTNU/Energy and Process engineering
Professor Tore Undeland, NTNU/Power engineering