By Eoghan Quinn, Global Wind Lead
WorleyParsons Group
In 2017, the offshore wind industry hit milestones and made headlines. That breakthrough year saw the sector become more commercially viable and realize its global potential. Wind Europe said that in 2016, the sector added 25% wind capacity. That was on average, the capacity of 500 more turbines connected to the grid. What’s more, the Global Wind Energy Council reported offshore wind had its first subsidy-free tender in Germany, for more than 1 gigawatt (GW) of new offshore capacity. And that was just the start.
Floating wind turbines are the next frontier for the offshore wind industry. There are challenges aplenty but the lure of 60% capacity factors is too good to resist.
Having made the leap from onshore to offshore, the industry is poised to make another significant move: the jump from fixed-base to floating offshore wind. As with the first shift, this entails new layers of fiscal, technical, operational, and regulatory complexity. It’s a tough challenge, but the rewards are enormous because most of the potential global offshore wind resource is in waters too deep for conventional fixed offshore wind.
The leap is similar to when the oil and gas industry started building floating structures in the 1970s, a move which also opened new deep-water markets such as the Gulf of Mexico, Latin America, and West Africa. It’s a high risk, high reward strategy. Much like the evolution of floating structures in oil and gas – SPAR, tension-leg platforms, and even new low-motion FPSOs – if those tapping into floating offshore wind want to get it right, they will need to draw on the expertise of those familiar with the complexities of designing, building, operating, and maintaining assets in these highly complex offshore environments.
Making waves
Wind is in its ascendancy. The last 12 months were monumental for the sector, with major projects for developers such as Orsted, Vattenfall, and Statoil agreed without subsidies for the first time in the industry’s history. A target to reduce costs to €100/megawatt hour (MWh) by 2020 was surpassed four years early – and by a significant margin. More than 3,000 MW of new offshore wind capacity was installed in Europe alone (double that in 2016), taking the total to nearly 16 GW.
Yet, the industry is just scratching the surface. Most of today’s installed capacity is in shallow water. It’s what you might call the low hanging fruit.
About 80% of Europe’s potential offshore wind resource is located in water more than 60-m deep. This equates to 4,000 GW of untapped potential in Europe alone, and a further 2,450 GW in the U.S., 500 GW in Japan, and 90 GW in Taiwan, according to the UK’s Carbon Trust and Taiwan’s Ministry of Foreign Affairs.
Fixed-based wind is not viable in water depths of 60m and more. But floating foundations are. A floating foundation can surmount the engineering challenges of deep-water installations, and it offers a different approach to construction that also yields benefits. For example, instead of conducting most building work at-sea using costly heavy-lift vessels, most of a turbine can be constructed quayside and pulled into position by less costly and readily available tugs. Manufacturing and construction costs could tumble.
By using deeper waters, floating offshore wind farms also make projects feasible in remote locations that offer more powerful and reliable wind. However, this must be weighed against higher transmission costs.
It’s unsurprising that developed and developing nations are now pursuing offshore wind farms, thanks to the significant cost reduction in fixed-bottom wind (a 32% decrease since 2012 according to Offshore Renewable Energy), and the increasing confidence in offshore renewables as an investment proposition. In 2017 alone, more than €7.5 billion was invested in new European assets.
Japan has been testing a number of floating offshore wind prototypes. France has launched ambitious plans for a string of pilot projects off its coast. And Norway recently agreed to move forward with demonstration projects in its own waters. These countries see the potential to build their economies around renewable energy. This energy transition is mostly backed by oil and gas developers, looking for ways to reduce their carbon footprint by diversifying their core business.
Most concepts for floating wind turbine foundations fall into one of these three categories.
Last year was a turning point for the floating wind industry. Statoil installed the world’s first floating grid-connected offshore wind park, Hywind, offshore Scotland. The 30-MW, five-turbine pilot wind park has already performed better than expected, despite experiencing a hurricane and wave heights up to 8.2m during its first three months in operation.
Statoil reports that the typical capacity factor for a fixed offshore wind farm during winter months in the North Sea is a respectable 45 to 60%. More remarkably, Hywind achieved 65% during November, December, and January 2018. The fact that a pilot floating project is already meeting and surpassing the performance standard set by its fixed-base forbears bodes extremely well for floating’s future.
Complex challenges
The fixed-foundation offshore wind industry is young but already contemplating16-MW turbines as tall as London’s Shard. Recall that 3-MW turbines were considered ambitious just five years ago.
The floating wind industry, however, is still in its infancy. There’s not one technology proven to the point that it can be purchased off the shelf. A Carbon Trust study identified 30 different concepts in the market, mostly based on semi-submersible, tension-leg platform or SPAR structures, all of which, have been borrowed from oil and gas. However, many of these systems have yet to be tried, developed, and proven for floating applications.
As firms start to move from concept to trials and even pilot arrays, they will need specialist expertise to de-risk and optimize their designs for a full project lifecycle. Some of these challenges will be technical, such as developing dynamic power cables that can survive harsh offshore environments, or designing foundations and methods for mooring turbines to the seabed. Others will be regulatory, such as the U.S.’ Jones Act, which pushes up transport costs. Nor do obstacles end at construction: there will undoubtedly be operations and maintenance challenges, constraints around vessel availability, and difficulties in servicing floating arrays efficiently.
Unlocking complexity
These challenges are not insurmountable. With the right experience and support, floating offshore wind can become an economic reality. Projections from the U.S. Department of Energy suggest that floating foundations will be cost-competitive with fixed wind by the mid-2020s, while the International Renewable Energy Agency predicts that the first large-scale floating wind farms could be installed by 2025.
The industry will start to see concepts that draw on existing capabilities, such as concrete structures that can be built, floated out, and moored. We’ll also start seeing systems that are scalable and efficient, using off-the-shelf turbine towers, similar to the IKEA-style model we saw for onshore wind.
Success will come down to unlocking complexity, and one of the surest ways to boost its chances is to rely on proven expertise. But how do you find that experience in a fledgling sector?
One option is to look sideways. Decades of accumulated relevant expertise in the oil and gas sector date back to the North Sea’s first floating production systems in the 1970s. Engineers there know the environment and have cracked the main engineering challenges. They have the experience to navigate the complex marine environment.
Other experts are working with governments and investors to reduce project costs. On the other side of the energy coin, there is a burgeoning pool of expertise in renewable projects, specifically wind. Developers who can collate this expertise, either in-house or through partnerships, will be best placed to succeed.
The WorleyParsons Group, for example, has years of experience across the conventional power and renewable energy sectors and is working with governments and companies around the world on onshore and offshore wind projects. The company is advising one partner on how floating wind can augment the power supply to an oil and gas production facility. Each project presents different challenges and opportunities, but one consistent driver is the growth in the renewable market supported by the momentum of the global energy transition.
Floating offshore wind offers huge global green-energy potential with projects getting bigger and more multifaceted. But these complex, deep offshore environments will require reliable and tested technology, a strong onshore infrastructure, and the right expertise to ensure success. By partnering with companies already in this space, the sector can unlock that complexity and begin to realize its potential.
Filed Under: Construction, News, Offshore wind, Projects
