Wind energy expert says massive offshore target ‘is within reach’

In the next decade, a huge amount of bottom-fixed offshore wind far exceeding capacity already installed will be built, but as John Olav Tande, a senior research scientist at Sintef told OWJ in an exclusive interview, floating windfarms will be the key to meeting the kind of huge, long-term targets now being discussed.

Chief scientist Tande founded Nowitech, a €40M (US$45M), eight-year research project on offshore wind that was completed in 2017. He was a research scientist with the Norwegian Electric Power Research Institute, worked at the Risø National Laboratory in Denmark from 1990 to 1997 and has worked on many aspects of wind power, including heading working groups at IEC and IEA, EU projects, and Norwegian national research projects.

Chief scientist Tande said the 1,400 GW target announced by Ørsted and Equinor and partners in the Ocean Renewable Energy Action Coalition is approximately 47 times more than is installed today (around 30 GW). To reach that target, installed offshore wind capacity would need to increase by 46 GW every year. “This is significantly higher than the current rate of offshore wind installation, but still realistic,” he said.

“It would require a significant acceleration in the development of offshore wind, but the development of onshore wind has proved that this is possible, with annual installations around 50 GW for the last few years.”

Chief scientist Tande said the target also plays well alongside the scenario set out by the European Commission of 230 GW to 450 GW of offshore wind by 2050. In the European Commission’s scenario for a carbon neutral Europe by 2050, with 450 GW of offshore wind capacity, offshore wind will be a main source of electricity in Europe.

“Wind conditions offshore are very favourable, enabling offshore windfarms to generate large amounts of energy,” he explained. “Assuming 4,000 full load hours per year, the 1,400 GW of offshore wind would deliver 5,600 TWh annually. This is high in comparison with land-based wind, but more or less what we should expect from good offshore conditions.”

Chief scientist Tande said developing this amount of offshore wind would require a transformation of the industry with a significant build-up of supply chains and the introduction of new technology, but he says the sector already has the basic building blocks. “We just need to scale it up,” he said, although that is not a challenge he takes lightly.

Floating wind will play a particularly important role in ramping up offshore wind capacity, chief scientist Tande said. Although the market is still at an early stage with only a few pilot projects in operation, potential global capacity is huge.

According to International Energy Agency’s Offshore Wind Outlook, 2019, 80% of the global offshore wind potential is in areas with deep water that can be exploited by floating wind technology and, potentially, meet the world’s current demand for electricity more than 14 times over.

“To achieve this, offshore wind will need to be installed at an increased rate, and research will be needed to address challenges such as transmission system technology, subsea technology and how wind power in such large amounts can be integrated into the electricity grid of the future while ensuring grid stability,” chief scientist Tande said.

“And alternatives should also be explored, for example, using offshore wind to produce hydrogen, or to create ‘charging hubs’ for electrically powered vessels.” There are, he says, a host of ‘multi-use’ options.

“Hydrogen and ammonia make very good non-carbon energy carriers for the power generated by offshore wind,” chief scientist Tande told OWJ. Offshore wind can generate a lot of power, he said, but if it is far from shore a way to turn it into something else to bring it ashore might be required. One day, he suggested, energy carriers such as hydrogen could be produced offshore and brought to land by specialised tankers like a shuttle tanker in the offshore oil and gas business.

“The good news is that we know how to address many of the challenges that such a large amount of offshore wind would pose,” chief scientist Tande said. “We also know that in future offshore wind can meet these ambitious goals without subsidies. What we need to do is industrialise offshore wind, particularly floating wind. If we can do that, floating can compete with bottom-fixed on price.

“We need to identify which of the many floating wind solutions that are being proposed is the best. Spars and semi-submersibles both have advantages, but manufacturing spars is not easy unless you have deep water close to shore as we do in Norway. There are a lot of semi-subs that have been proposed, but we need to identify the best.

“Building huge floating windfarms far from shore means that grid connection will be a challenge, as will inter-array cabling within floating windfarms. But there are examples of how we might go about this, whether the solution is a floating substation or something subsea.

“Operations and maintenance (O&M) will also be a challenge so far from shore. It is going to make the need for remote monitoring even more important. We are going to need to make use of digitalisation and digital twins, but this is also doable,” he said.

Another challenge he identified also relates to O&M. “Heavy maintenance on floating turbines could require a lot of thought,” he concluded.

“You will have a floating turbine that moves, and a ship that moves, and could need to conduct lifts and undertake work 200 m above sea level.”

That is a huge technical challenge, he agreed, but given the technology challenges that have already been successfully addressed by the industry in such a short space of time, not one that is impossible to overcome.