The previous year was quite an important milestone in Europe. According to this for the first time report According to a publication by the think tank Ember, wind and solar energy are surpassing fossil fuels in the EU’s electricity mix. The European Electricity Review analyzes full-year electricity generation and demand data for 2025 in all 27 EU countries to understand the region’s progress in transitioning from fossil fuels to clean electricity. It is the tenth annual report on the EU energy sector published by Ember.
The report noted that Electricity generated by wind turbines and solar panels would account for 30% of electricity production in the EU in 2025, more than the 29% produced by coal, oil and gas-fired power stations. Solar energy generation was particularly high, reaching a record 369 TWh in 2025, the report said, 20% more than the previous year.
But while several experts point to a tipping point, the challenges of accommodating intermittent energy sources such as solar and wind energy into the grid remain. Energy storage using large lithium battery packs and pumped hydropower are the two favorite options of utilities around the world. (For more information on the topic of energy storage batteries, read: The pros and cons of batteries for energy storage | IEC e-tech).
However, other solutions are emerging, which their proponents claim are cheaper and/or cleaner. One of these is the generation of energy at sea. The energy that comes from the sea and rivers is very diverse and completely renewable. The potential for harnessing energy from the ocean and rivers is still largely untapped and enormous.
Different types of marine energy
One of the ways to convert the ocean’s energy into electrical energy is by using tidal energy. Tidal turbines generate electricity from the tides caused by the moon’s gravity. They can be mounted on the seabed or float like a tethered submarine with turbines (tidal current), or integrated into a barrier on a lagoon (tidal range). Like other forms of maritime energy, tidal energy is renewable and also predictable (unlike solar and wind energy). Although the tides change regularly depending on the time of day, they follow a consistent pattern and can be predicted accurately. “You can predict in a hundred years when you will have an energy peak!” says IEC expert Peter Scheijgrond enthusiastically.
At his company BluefeatherPeter Scheijgrond and his team are building public-private partnerships to help technology developers, research institutes and governments get their sustainable energy projects in the oceans financed and implemented, with an emphasis on demonstration at sea.
Other marine energies include ocean thermal energy, salinity gradient energy, and wave energy. Thermal conversion in the ocean takes advantage of the temperature difference between deep water and surface water, and is being tested mainly near the Indian coast, while generation of salinity gradients converts the difference in salt concentration between fresh and salt water. Wave energy converters capture energy from the motion of waves through floating or submerged devices.
Tidal energy is the most promising for the time being
Several experimental marine energy projects exist around the world using one form of generation or the other. But tidal energy is seen by experts in the field as the form of marine energy most likely to enter the commercial space soon. “Of the different types of marine energy, tidal energy comes closest to farm-scale projects. Proteus with four turbines on the seabed of the Pentland Firth in the north of Scotland, it has been producing grid electricity for more than seven years. Another promising project is the latest announcement of funding for several tidal farms at Morlais, in a marine area near the North Wales coast. These will be the first commercial tidal farms from 2028,” describes Peter Scheijgrond.
Maritime technology has been slow to develop into an industry due to the initial high installation costs and the problems associated with generating energy under harsh environmental conditions. Convincing regulators to participate has also been a tall order. As Peter Scheigrond explains: “Our biggest challenge is to get regulators to understand the technology. It can take a very long time before we get the permits to continue building marine energy systems. Most of the time, regulators do not know the difference between wave and tidal energy. We still have a lot to do to raise awareness.”
Sea energy can compensate for fluctuations
But for Scheijgrond, one of the overlooked benefits of marine energy is that it can provide a renewable form of energy to offset the variability of wind and solar energy. “We see the limitations of solar photovoltaics (PV) and wind energy. These energies cause net congestion and variability in electricity supply during the day, but also during the seasons. Their market value also varies enormously, and there is a need for complementary electricity sources that can be produced at times when solar PV and wind do not generate enough. We also need a solution that is cheaper and cleaner than large battery systems for energy storage. Marine energy can play an important role in this context, because it is a predictable renewable resource that can add value to energy storage in the energy system by generating energy when other renewable sources are less available.”
According to Scheijgrond, there are many different market demands for marine energy. “Developers see many end-uses for marine energy technology, some of which are niche markets. For example, there is a demand for small autonomous energy applications at sea to power remote sensing. All you need is a very small wave energy buoy that can monitor the environment 24/7. The price point (or levelized energy cost) for that “service” is much less relevant than for grid power applications. The next niche market could be island and coastal communities, which have high energy costs. Much of these remote areas communities are not well suited for large-scale wind farms. Solar PV can be part of the solution, but it does not generate power at night and typically requires large areas of open, unobstructed land. Marine energy can be used in a hybrid form, combined with solar PV and batteries, to power a microgrid,” he says.
Other demands include, in his words, “large-scale deployments, such as the Welsh tidal project I mentioned, which will supply power directly to the grid. There is another similar deployment near Brittany in France, in the Raz Blanchard. Both France and the UK will accept a higher price because they have a strategy for building a maritime energy industry. In the longer term, I foresee a fully integrated offshore energy system combining wind, wave and offshore solar energy. Because these resources peaks at different times, they can complement each other and help balance daily and seasonal variations in energy generation, excess electricity can be used to produce green hydrogen,” he adds.
Standards and certification are essential for an emerging industry
Whatever the future deployment of marine energy projects, they require standards and testing/certification to make the transition to commercial use, and that is what the IEC provides.
A technical committee of IEC, TC 114was specifically set up to develop standards for marine energy conversion. It has produced many first editions of technical specifications. According to Scheijgrond: “These technical specifications provide a structured framework that helps guide the development and testing of emerging marine energy technologies. At the same time, their application in real-world demonstration projects allows us to gain practical experience that can be fed back to the ongoing work of the maintenance teams and ad hoc groups responsible for developing the second and third editions of these standards.”
But independent testing and third-party certification are just as crucial, he says. “We want marine technology and marine energy to be successful – that’s what we intend to do. And for that to happen we need an independent third-party certification framework. Without that, projects will have trouble becoming financeable. You need a stamp of approval to ensure that the product is validated, verified, safe, especially for the environment, and will perform as expected. Agnostic investors or insurers need that stamp of approval before they trade. They will handle the financial risk on board, but need to be reassured about the technology, that it will work for fifteen years and deliver what it says on the box. Large-scale rollout requires investments of hundreds of millions of dollars, and investors are generally not technology specialists; they rely on certification to ensure that the systems they finance will function safely, predictably and over the long term. IECREcomes in,” he concludes.
It seems increasingly likely that harnessing the potential of marine energy will pay off for those involved.
Author: Catherine Bischofberger
The International Electrotechnical Commission (IEC) is a global non-profit membership organization that unites 174 countries and coordinates the work of 30,000 experts worldwide. International IEC standards and conformity assessment are the basis of international trade in electrical and electronic goods. They facilitate access to electricity and verify the safety, performance and interoperability of electrical and electronic devices and systems, including, for example, consumer equipment such as mobile phones or refrigerators, office and medical equipment, information technology, electricity generation and much more.
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