The energy revolution from the sea

Sometimes, the best ideas come when you least expect them. Philipp Sinn went on a sailing trip to get away from the stress of his job as a consultant in the automotive industry. As the waves crashed around him, his mind turned to the huge amounts of energy that they must contain. Back home, he designed a cost-effective way to turn this energy into electricity without the need for complex technology. This idea turned into a PhD thesis that went on to form the basis for the company SINN Power, founded in 2014. Today, the company is based in the same house where Sinn once lived in Gauting near Munich. It employs ten people who all work on the future of energy supply, along with up to 15 students who bring fresh insights from their studies. “They are an important pillar of our company”, explains Sinn.

The basement is home to the tinkerers and inventors. This is where the metal components, PCBs, generators, measuring equipment and cables are combined to form modules. These are then combined via a lightweight connection mechanism to form larger floating arrays. Each module features a disc-like float at the bottom, measuring up to three metres in diameter, which rises and falls with the waves. This movement is then conveyed upwards by a ten-metre-long rod, which drives up to eight generators that turn the movement into electricity. The next stage of development will be to fit a synchronised gear that ensures that the generator always turns in the same direction, regardless of whether the rod is moving upwards or downwards. 

Johannes Stuck, responsible for business development at the company, shows how well the system works with a video shot last winter in the harbour of the Greek city of Heraklion. The video shows huge waves in a storm crashing against two second-generation modules that have been fixed to the quay wall since June 2018. “Everything survived unscathed”, he assures. This was thanks to the special design and robust components. These components include cables and connectors from the German world market leader LAPP that are capable of withstanding the waves and seawater.

The man to thank for this collaboration is Hermann Robl and his quick thinking. The sales engineer discovered that someone from a previously unknown customer called SINN Power was browsing LAPP’s online store for cables and connectors suitable for use in seawater. Robl wanted to know more about the precise application. “I paid them a visit and was fascinated immediately.” LAPP has been supporting the start-up ever since with the necessary connection components and technical information. “The potential of this technology is massive”, explains Robl.

The installation in Heraklion transmits live operating data in real time to Gauting. Each module generates 24 kilowatts at their peak. The average output is a more modest 2.5 kilowatts, however using a small float. The company plans to fit the next generation of modules with larger floats measuring three metres in diameter, which will allow them to generate twice as much electricity. An array of this kind, measuring a minimum of seven by three modules, will be capable of generating 550,000 kilowatt hours per year. This would be enough to supply around 100 households with electricity¹.

One disadvantage that many renewable energy sources share is that they are not capable of generating electricity consistently. Even the largest wind turbine is useless if the wind is not blowing, and cutting-edge photovoltaic units cannot generate electricity at night. Filling these gaps with clean energy requires an alternative. This is where wave power comes in. It is capable of covering the base load, i.e. providing electricity when other sources cannot. This kind of combination is a particularly interesting option for decentralised power generation, such as on an island. But the technology’s potential is much greater than this. SINN Power plans to install wave energy converters in the unused spaces between individual turbines in large offshore wind farms. Another option is to attach them to harbour walls like those in Heraklion. 

The area around the equator offers the best conditions for these systems. Johannes Stuck illustrates this by showing a map of the world, on which high waves with large amounts of energy are marked in green and the continuity of these waves is marked in shades of blue. Areas with both of these are the perfect location for wave energy converters. The Caribbean, for example, is ideal because it offers high waves year-round. The region also offers a perfect market for the technology, as the Caribbean islands spend 1.3 billion euros every year on electricity produced by diesel generators. Alongside this financial benefit, there is also the environmental benefit of doing away with polluting diesel exhaust fumes.

The first enquiries have come from Africa, a continent with many coastal communities and often poor power supply. The Cape Verde islands gave SINN Power the opportunity to begin turning its wave power technology into a commercially viable solution. A project to power a shrimp farm using wave energy is due to be completed by 2021. SINN Power is also conducting a feasibility study in the Guinean port city of Conakry for a British and Israeli consortium. The ultimate aim is to build a wave power station to supply electricity to the local area. The initial measurements underline the benefits that a combined installation would offer here. During the rainy season between May and September, the energy density of the waves increases just as that of solar and wind energy is falling.

Philipp Sinn is not the first person to have the idea of harnessing the power of the waves to generate electricity. The first experiments date back to the 18th century, although they ultimately proved to be too complex and expensive. So what makes SINN Power different? “Our modular design offers cost-effective scalability”, says Johannes Stuck. The company’s competitors build their systems in shipyards before towing them to where they are required. These usually consist of heavy components and are not scalable. Many of the world’s coastal regions lack the necessary infrastructure for these projects. By contrast, SINN Power constructs its modules directly on site. The system still requires authorisation from Hanseatic Lloyd, however, as it is considered an anchored ship from a legal perspective. Philipp Sinn is proud that in just three years, his company’s technology has overtaken that of all of its competitors to become market leader: “That’s despite the huge amounts they’ve invested over decades.” The central features of the design are now protected in a series of patents.

2019 will see the tests expanded. Three new, technically advanced modules will be installed in Heraklion. These will be followed in 2020 by the first floating power station consisting of 35 individual modules. Cables from LAPP will be on board here too. The global market leader for integrated connection systems wants to use the cooperation to make its own products even better. One of Robl’s suggestions was to remove the cables in Heraklion after a year and have them tested in LAPP’s own facilities, in order to find out whether the plastic in the cable glands has changed. Alongside the SKINTOP cable glands, LAPP also provides the ÖLFLEX cables that convey the electricity from the generators, as well as the UNITRONIC data transfer cables and control cables like the ÖLFLEX ROBUST 210 and the wiring on the PCBs. Undersea cables are also planned. “I knew LAPP from my time working as an apprentice electrician at BMW and relied on their products”, explains electronic engineer Simon Krüner. He is responsible for developing the electronics at SINN Power and is very satisfied with the support from LAPP.

Hermann Robl has promised to continue this support in the coming years, as SINN Power estimates that its technology will not be ready for market until 2021. The priority now is to reduce costs through a combination of large numbers of identical components and a controller that can predict wave patterns hours and days in advance. Within five years, SINN Power aims to sell the electricity generated by its wave power stations for less than ten euro cents per kilowatt hour, depending on the respective wave conditions. This will make it competitive against other renewable energy sources and especially against diesel generators. The company has secured long-term financing through investment partner Schweizer Kapital. “60 per cent of the world’s population live on the coast”, says Philipp Sinn, “and wave energy can cover a significant proportion of their electricity needs.”

LAPP already has experience of renewable energies from other projects, such as connection systems for solar power. In 2016, LAPP provided cabling for wind turbines with integrated pumped storage. Max Bögl Wind’s natural energy store in Gaildorf near Stuttgart is helping the energy revolution reach new heights. When there is excess wind energy, water from the valley is pumped up into the pumped storage. From here, it can compensate for periods of low wind with the help of three powerful turbines in the valley. LAPP provided the control cables, thick power cables and data cables for the wind turbines through just-in-time delivery at the construction site.