Energy from the power of waves

Wave power is the transportation of energy by ocean surface waves and the capture of that energy for, among other things, generating electricity, desalinating water and pumping water into reservoirs. A machine able to exploit wave power is generally known as a wave energy converter (WEC).

The idea of harnessing energy from ocean waves has been around for more than 200 years but was not pursued scientifically until the 1940s and 1950s in Japan, after which it declined. Interest was again aroused in the early 70s during the oil crisis when several universities examined the potential for using ocean waves to generate energy, primarily in the UK, Norway and the USA.

Converting energy

There are today four main technology systems for converting wave energy to usable power:

  • point absorber buoys
  • surface attenuators
  • oscillating water columns
  • overtopping devices.

And all are positioned at shoreline, close to shoreline and offshore.

Figure 1. An example of using waves to create electrical power.

Corrosion risks

Typically for marine environments, corrosion is always a challenge and duplex materials like Sandvik SAF™ 2507 are an excellent choice, where ASTM 316L materials will corrode. Our duplex steels are also relied upon extensively in the offshore oil and gas industry.

Tolerances

When tolerance requirements are tough, good machinability is another essential component. Sanmac® 2205 is a duplex stainless steel with excellent machinability and high resistance to stress corrosion cracking (SCC) in chloride-bearing environments. High mechanical strength completes the package – with roughly twice the proof strength of austenitic stainless steels like ASTM 316L.

Sustainable energy

The risk of climate change and the growing interest for sustainable energy production in later years has seen a number of new patents and an increase in wave power activity, particularly in the UK, where the world’s first marine energy test facility was established in 2003. Wave power as a source of energy could make diesel generators unnecessary for innumerable small island habitations and coastal areas far from the nearest land-based source of electricity.