Clean Power

Published on June 19th, 2014 | by Silvio Marcacci


A Simple Solution To The Complex Problem Of Offshore Wind Costs?

June 19th, 2014 by  

Offshore wind’s benefits are clear – stronger, more consistent supply than onshore wind often located near constrained energy demand in large coastal cities. But power prices for offshore wind have remained stubbornly high, leaving regulators and developers alike searching for ways to lower costs any way possible.

Considering the harsh environment turbines operate in, maintenance work can be one of the most complicated aspects of offshore wind. After all, getting workers transferred to a turbine in deep, surging seas isn’t easy.

But if Windcat Workboats is correct, a simple solution to offshore wind’s cost challenge could increase maintenance efficiency and potentially lower operating costs. (Full disclosure – while my trip was sponsored by the Dutch Government’s Ministry of Foreign Affairs, it had no involvement in the editorial process of this post)

A Simple Solution To Boost Maintenance Efficiency

The Netherlands-based company, which touts itself as “Europe’s leading provider of specialist crew transfer vessels to the offshore wind power industry,” builds and operates a fleet of custom-designed ships to reliably transfer maintenance workers and equipment from shore or construction vessels directly onto turbines.

Windcat’s secret is simple – a strong custom-built hull connected to a rubber fender on the ship’s bow, filled with foam. As the ship approaches a turbine, its engines accelerate, molding the rubber fender around any docking point. While the boat moves up and down with the waves, a stable hinge-like fixed platform is created for workers to move from ship to turbine. Once workers are transferred onto the turbine, the boat ties up, waits for workers to complete their maintenance, and repeats the docking procedure to take them back on board.

Since starting the company in 2002, Windcat has safely transferred 1.1 million maintenance worker visits, using this straightforward approach. Windcat has grown fast from one boat in its first year of operation to a current fleet of 35 vessels, and is now active at offshore wind sites in six countries across Northern Europe for companies like Vestas, Dong Energy, and Siemens.

Lower O&M Costs Key To Competitiveness

So why does something as seemingly obvious as a custom-built boat with stable docking features matter? It’s all about functionality, according to a report issued last year on the offshore wind market’s potential growth.

Offshore Wind Toward 2020 forecast the offshore wind industry would become a €130 billion annual market by 2020, largely on the strength of a 14% reduction in operation and maintenance costs and a 12% increase in capacity factors. Both of these predictions are important to growth, as the report underlined the need to reduce offshore wind energy’s cost as a risk to global development.

The same report also found 28% of an offshore wind project’s lifetime costs come from operations and management, and noted vessels have traditionally been oil and gas industry ships modified for offshore wind use, but vessels tailored to the needs of offshore turbines could reduce total ownership costs – thus pushing down power prices.

That industry niche seems to fit Wildcat well. “We are the only company still building and designing boats just for offshore wind service purpose,” said Willem van der Wel, head of vessel and business development at Windcat. “All other companies take existing boat designs and modify them for service.”

The beneficial equation is clear – getting a greater number of maintenance workers from shore to turbine faster means less downtime and thus, higher capacity. Transfer-by-helicopter has also been an option for maintenance, but requires a complete turbine shutdown, further reducing capacity. “Vestas chose Windcat for servicing because they said more trips were accomplished,” said van der Wel.

Beyond more efficient worker transfers, Windcat’s custom design also affords more efficiency vessel maintenance, according to van der Wel. Workboats are built with direct access to their engine compartments, meaning if an engine needs replacing, it can be swapped out within a few hours as opposed to dry-docking and cutting through the hull as on other vessels, which can take days.

Bullish Outlook For U.S. Additions, Cost Cuts

Even though offshore wind has been concentrated in Northern Europe so far, Windcat is bullish on the prospects for American projects to come online in coming years. The company has formed a partnership with U.S.-based Seacor Marine, which traditionally operates in oil and gas maintenance, to comply with U.S. regulations and be involved in American offshore wind projects from the start.

No one solution is going to immediately drive down the costs of offshore wind, but as we’ve seen with other renewable energy technologies, a comprehensive approach drives down costs over time. “It’s not really competitive yet, but everyone is trying to drive costs down,” said van der Wel. “Hopefully all these things adding up will make it competitive in the end.”

Check out the below video to see Windcat Workboats in action, starting around the 30-second mark:

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About the Author

Silvio is Principal at Marcacci Communications, a full-service clean energy and climate policy public relations company based in Oakland, CA.

  • Bob_Wallace

    It would be interesting to hear about the various methods developed to reduce the cost of offshore wind.

    Also, do you have any feel for how often an offshore rig has to be visited each year for inspections and maintenance?

    • North Sea Shipbrokers

      Depending on the scope and turbine supplier the rig/substations/turbines needs to be checked ones a week or when a breakdown. It will be everyday under installation. Gangway is normally used in the installation period.
      We can support with a lot more detailed information, but our company have worked on this for some years now, and cannot post it here.

  • Hans

    It might also be worth to mention another Dutch invention: The Ampelmann. The Ampelmann is an hydrolic platform on a ship that is moved in such a way that stays still rleative to the offshore wind turbine. See for example:

  • MarTams

    A parasail would be cheaper, faster and safer than this custom boat.

  • dango-man

    Not going to change the cost of offshore and their are vessels that already exist that meet the industry requirements such as cTruk vessels. One of the main factors that affect O&M is distance from the port. As the distance increases the transport cost increases due to the requirements, with anything below 15 miles using a small vessel, 15-40 miles using vessel and a helicopter and 40 miles+ using large vessels with accommodation. Also as you get further from land the weather can make maintenance more difficult with turbine often having more down time the further they’re from land.
    The biggest cost in O&M is fixed costs which make about half of O&M with the majority of fixed costs being insurance, transmission and legal.

  • JamesWimberley

    Come on. The sole innovation reported here – a custom fender – is trivial and cannot make a significant difference to overall O&M costs. Good luck to Windcat and its workers in often harsh and sometimes dangerous conditions, but this is their corporate PR.

  • Offgridmanpolktn

    It will be great if a company like this can be in on the development of the US offshore wind development from the start so as to keep prices down and help prevent opposition. Hoping that they don’t run into conflicts with the Caterpillar equipment company, which has a strong presence here, over the ‘cat’ name.

    • Ulenspiegel

      Sorry, obviously the most simple solution for the whole off-shore problem is on-shore wind. With the current onshore turbines I do not see a good argument for offshore in the USA or Canada, even in most European countries on-shore is more than sufficient. The whole off-shore discussion still works with arguments from 2005, however, on-shore changed dramatically since then.

      • Bob_Wallace

        The majority of the US population lives along the coasts. The best US onshore wind resources are located in the middle of the country where fewer people live. Offshore allows for shorter transmission lines.

        Onshore wind tends to blow hardest during late night when demand is the lowest. Offshore winds tend to blow strong during daytime when demand is high.

        Onshore has developed nicely over the last few years. However many of those same improvements can be transferred to offshore wind.

        • Ulenspiegel

          The question is whether onshore wind plus storage is still much cheaper than offshore wind.

          In case of the USA with >4000 FLH at good onshore sites my bet is onshore.

          The basic problems of offshore wind are not solved with the introduction of slow wind turbines. 🙂

          At the moment offshore costs at least three times as much as onshore wind in the USA, optimists assume we can reduce offshore costs to 10 Euro cent/kWh around 2020-22, onshore is already around 5 US cent today.

          • Bob_Wallace

            We’re likely a few years from knowing the costs of offshore wind or storage. It could be the case that stored onshore would be cheaper than offshore. We’ll have to wait for time to tell us.

            There are advances in onshore that can be exported to offshore. Blade design, the use of sensors to detect component performance, systems for detecting changes in wind speed/direction.

            Onshore may have dropped below 5 cents and closer to 4. We should know before long.

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