The Status Quo of Harnessing Ocean Energies
The technologies used for the production of electric power from the mechanical, chemical and thermal energy of the oceans are still young and highly innovative. Their development is demanding: the oceanic environment is marked by harsh conditions, the high salt contents are harmful to the machinery, waves, wind and water unleash enormous forces. As far as research efforts go, the phase of technological experimentation is about to be finalized. Promising approaches are materializing, and the market-maturity of existing prototypes is continuously upgraded. The applied technologies are ready for proving themselves under commercial conditions. Yet relevant projects are often abandoned due to a lack of financial solutions.
The Potential of Ocean Energies
Ocean energies have potential. After all, 70 percent of the earth surface are covered by seawater. Voith has calculated that the wave, current and osmotic energies of the seas have a theoretical potential of 1.8 TW. If this potential was fully realized, it would cover 15 percent of the worldwide energy requirements and 70 percent of the global energy demand. According to Voith, some 100,000 wave, marine current and tidal power plants could be installed worldwide by 2030. In terms of price, electricity from ocean power stations could be at the same level as energy from offshore wind power stations. The European Ocean Energy Association claims that ocean energy power plants could provide an output of 188 GW by 2050 - provided there is sufficient investment and research success. This would correspond to an annual output of 645 TWh; enough to cover 15 percent of the EU electricity consumption. In Europe, ocean energy would thus have a share in the mix of regenerative energies that could be compared to the current status of wind energy.
Ocean Energy Technologies Need Political Backing
The technologies for harnessing ocean energies are ready for the market, but their commercialization has so far been hindered due to a lack of project financing - a scenario that has been primarily caused by the worldwide economic crisis. Yet it is also an adverse effect of Germany's withdrawal from nuclear power and the newly introduced taxation on nuclear fuels. Both measures leave German energy companies short of sufficient financial scope for investments in renewable energies of the "next generation." This situation has a strong impact on the ocean energy industry with its high upfront investments. Energy suppliers with nuclear reactors in their power station park reduce their ocean energy teams, discontinue their project developments or make drastic cutbacks; some energy producers have (temporarily) withdrawn from the market altogether. Any remaining resources are put into ambitious offshore wind projects. "New renewables" are left behind. At the same time, politicians surely never intended to turn the exit from nuclear power into an obstacle to venturing into promising, not yet exploited renewable energy sources.
The following measures would be suitable for promoting the implementation of the innovative potential of ocean energies, a potential that is equally valuable from an ecological and economic aspect:
- Setting off a proportion of the nuclear fuel tax against investments in (new) renewable energies, or tying its utilization to the promotion of (new) renewable energies, similar to the new tax reform legislation.
- Tendering for financial project sponsorship on a regional, federal or EU level on a scale that is suitable for ocean energy projects (so far the relevant sponsorship funds have been either too small or too big) - also for projects outside Germany.
- Risk assumption for ocean energy projects by public offices on regional, federal or EU level.
- Investment grants from suitable development banks on regional, federal or EU level (L-Bank, KfW, EIB). Aspects such as innovative capacity, energy-political benefits, export orientation as well as energy supplies of developing countries might be initial starting points.
- EU-wide preferential treatment of electricity from ocean energies in all respective national regulations on feed-in tariffs.
Voith ─ Pioneer for Harnessing Ocean Energies
Voith was the first industrial player to recognize the potential of ocean energies. Since the mid-nineties, the company has been acting as a pioneer in the research and the development of technologies for generating electricity from ocean energy. In the meantime, Voith is the leader in the segments wave energy and tidal current energy.
Flagship Projects in the Wave Energy Sector
With LIMPET on the Scottish Isle of Islay, Voith Hydro Wavegen opened the world's first wave power station with a continuous connection to the public grid in 2000. Today, LIMPET, with 10 years of service, 70,000 hours of power input and an availability of more than 98 percent over the last two years, holds the record among wave power stations by a long way in terms of performance and reliability. In 2011, Voith installed the first commercially operated wave energy plant in Mutriku, Spain. With an output of 300 kW, the power station supplies some 250 households with electricity.
Voith is currently looking for an investor for what will be the world's largest wave energy scheme: the Siadar Wave Energy Project (SWEP). By 2012, 30 turbines outside the Scottish Hebrides Isle of Lewis could produce 4 MW; with an annual output of more than 12 GWh, 2500 households could be supplied. SWEP would largely operate commercially, it is self-funded within the scope of subsidies from the Scottish government.
The Technological Approach of Voith in the Wave Energy Segment
Voith Hydro Wavegen, the Voith center of competency for wave energy, utilizes the oscillating water column (OWS) principle for its wave energy projects: waves flow through a hollow chamber that is open to the sea and cause the water surface on the inside to oscillate. During this process, the air column above the surface is regularly compressed and decompressed. A Wells turbine converts the periodic pressure changes into rotational energy, which is turned into electricity by a generator. As the Wells turbines function bi-directionally without adjustment of the rotor blades, the number of moving parts is reduced, minimizing maintenance requirements and downtimes. Installed in a collector facility at the coast or in near-shore coastal waters, the rated output of a Voith OWC turbine is currently between 20 and 500 kW. Alternatively, the technology can also be incorporated in harbor piers or breakwaters, which reduces construction costs. In this case, the output of an individual turbine ranges from 20 to 130 kW. Wave energy plants can always utilize existing infrastructures along the coast, making the connection to the public grid quite easy. Another aspect in favor of the OWC approach is that Wells turbines rotate in the air, keeping the eco-system "ocean" undisturbed.
Pilot Project in Tidal Current Energy
Voith also plays a key role in the development of tidal current energy: Voith Hydro Ocean Current Technologies currently delivers the technology for the South Korean Sea Turtle Tidal Park. With a nominal output of more than 100 MW, this project will set new dimensional standards for ocean current power plants.
The Technological Approach of Voith to Producing Tidal Current Energy
Voith is using a free-flow horizontal axis turbine for gaining electricity from tidal currents. This turbine converts flow energy into horizontal rotation, by which a generator produces electricity. A carrier structure keeps the turbine-generator set on the offshore seabed. The construction consists of only a few moving parts with a robust a seawater-resistant design. Once again, the inflow to the rotor blades is bidirectional, they do not have to be adjusted in accordance with the flow direction. In order to eliminate the need for expensive special ships, the Voith concept includes a reversing module that can be installed on a standard loading vessel. The eco-system "ocean", too, benefits from the minimalist design: the bearings are lubricated by seawater, harmful oils are not required.
Voith ─ Innovation Driver in Hydro Power for 130 Years
Voith is optimally equipped for the technological and economic challenges associated with the further development of ocean energies. The company can rely on strong partners: joint ventures with RWE Innogy Ventures and Renetec are already in place, and there are also cooperation agreements with Bauer Renewables and Hochtief Solutions. As a family-owned company, it is Voith's ambition to do pioneering work in research and development. At the same time, the Group adopts a long-term perspective towards the commercial viability of innovations. Voith is, after all, able to look back on nearly 130 years of experience in the hydro power industry. Voith Hydro is a leading supplier of hydro power technology in the world market, one quarter of the hydro energy generated worldwide is produced with turbines and generators from this Group Division.
