Interview by Rikki Stancich

Wind Energy Update: Sea Energy recently signed an exclusivity agreement with Ampelmann for quite an impressive self-stabilising access system. Can you explain the advantage of this access system?

Michael Comerford: The system was developed by the Technical University of Delft – Ampelmann is a spin-off company from Delft.

The access system is a bridging system that takes out the motion of the ship in all six directions of motion (horizontal, vertical, rolling etc.), via an intelligent control system that feels how the ship moves and moves the access bridge to counter that motion. It absorbs the movement of the ship and keeps the platform and bridge hovering in the air, motionless relative to a fixed object like a turbine tower.

Wind Energy Update: What are the Ampelmann’s advantages over other access systems currently in use?

Robert Trahan: Advantages are that it doesn’t require any fixtures or fittings to the individual turbine structure which can be very costly to install and maintain in large wind farm arrays. The Ampelmann gangway maintains its position through pressure. It exerts a pressure of between 200kg-500kg  to maintain contact with the structure. Should the vessel move slightly in its envelope, the gangway can move in and out 8m.

Furthermore, the Ampelmann allows people to walk to the intermediate or main platform. This means maintenance crew no longer have to climb unprotected vertical ladders. Landing on the main platform also allows easy evacuation of injured crew on a stretcher.

Wind energy Update:  Sea Energy Marine is developing a new vessel designed to address turbine access and far shore O&M issues. What design features have been built into the Ulstein X-Bow to facilitate ease of access?

Michael Comerford:  The X-Bow was patented by Ulstein Design and Solutions of Norway. Working together SeaEnergy and Ulstein have developed a similar concept for the stern, whereby pitching of the vessel will be hugely reduced. We are installing a very high performance Dynamic Positioning system along with a unique propulsion system, which has the ability to limit roll whilst the vessel is maintaining its position. No ship has ever been built like this.

We really started with a blank sheet, with safety, access, and high quality living conditions in mind. A key issue in the offshore wind industry at present is staff retention, due to the discomfort of bouncing around in a catamaran and safety issues presented by stepping from the catamaran to the turbine ladder in rough conditions.

The less the ship moves, the more Ampelmann can operate. You can operate the ship and the Ampelmann in a wide range of weather conditions.

Wind Energy Update: How will the SeaEnergy Vessel System compete on cost?

Robert Trahan: Through the integration of leading edge proven technology these bespoke marine assets maximise the economic value of offshore wind farms by creating the widest window of safe reliable access during the Commissioning and Service phases.

The vessel system is not just for the very large far offshore projects of Round 3. To give an economic comparison between the standard Personnel Transfer Vessel, a shore based catamaran workboat, our vessel when deployed on near-shore wind farms is competitive in cost per hour based on technicians productive of work.  For far-shore wind farms there will really no alternative.

Wind Energy Update: When will new vessel will be in the water and what sized fleet are you looking to build?

Robert Trahan: We’re planning for 1Q 2013. The vessel will take 18-24 months to construct after award of contract. We are looking to build around 12 vessels over the next 5 years, and 2-3 of those by 2013.

Wind Energy Update: What level investment does this require and is the demand there for these vessels?

Robert Trahan: In the region of a £500-600 million investment. We are creating the demand for this. Until now, the industry has used shore-based cats and jack-ups, but we are presenting a cost effective option that has not been previously available.

We offer a much greater percentage of access than is currently available. By providing access in up to 4 metre sea we can offer close to 100% deployment of the technicians to the turbine throughout the year. Currently they are lucky to get 80%. Most developers have already contracted vessels for the next 2-3 years, but they now realize that when it comes to access, safety, availability and comfort the large-scale wind farms under construction and planned present a whole new set of challenges that are not being met with existing methods.

Wind Energy Update: From an operational perspective, what are the key advantages of having a vessel and personnel on-site all the time?

Michael Comerford: Onboard the ship, there will be a site operations office where the technicians will received a detailed, specific briefing and it will be confirmed that they have all the right tools and materials that they need.

This is a lot better than being briefed on the quayside. A big problem at the moment is that people get on the work boat and realize, half way to the turbine that a key tool has been left behind. Also, currently you need 4-6 work boats with 12 technicians per vessel going out to blitz the O&M work, due to the limited weather windows.

Our vessel can take between 24-36 technicians, plus crew, so a total of 50-60 personnel, which can service 100-200 turbine wind farms. Because the vessel is in the sea all the time, fewer technicians are required to carry out preventative maintenance throughout the year.

With 32 technicians, everyone is able to work a full 12-hour day, and during the  hours of night, the vessel can reposition to another section of the wind farm ready to carry out maintenance the next day. 

This is in a stark contrast to the current situation, where a technician’s day begins on the quayside, waiting for the work boat to ferry them to the turbine. The last technician in the boat could be waiting hours for their turn to get off and begin work.

This means that the technician has only 8 or even 5 hours of productive time, so the cost per productive hour is much higher. Our vessel, on the other hand, gives the versatility of 16 hours of a planned O&M program every day.

Wind Energy Update: During the installation and construction phase, how can this vessel increase productivity and lower costs?

Robert Trahan: Construction of a 500MW wind farm currently takes 18-24 months to complete because the installation vessels and work boats are only operational 7-8 months of the year.  There is roughly a £100 million per year spend on marine.

If you can work one year continuously , you can accelerate  first production by 6 months and save one year of marine spread costs. According to a report by The Carbon Trust this could add £130 million to the NPV of a 500MW wind farm.

This will also have the advantage of freeing up installation vessels, which are in short supply, for other projects

In addition to accelerating construction, for the O&M the operator is able to retain a smaller number of technicians to get through the same amount of O&M work in a year.

Access will be 92-97% of the time. To achieve the same number of working hours, five work boats with 12 people would be required, whereas our vessel needs only 32 people, so 50% less.

Mike Comerford: During winter storms, the wind is often at its best for productivity; but this is also when you have a higher chance of turbine failure. With shore-based O&M it could take 3 weeks for a decent weather window to get the work boat out to the turbine; our vessel could be there in a few hours. One turbine down costs in lost production about £8,000-12,000 per day, so to be able to get it restarted quickly is very important.

The real value of our vessel comes from the ability to provide technicians virtually immediate safe access to the turbines.  Reducing turbine downtime increases production which is key to profitability.

Wind Energy Update: Why are new vessels like the Ulstein X-bow and access systems like the Ampelmann necessary for offshore wind?

Michael Comerford: The vessel provides greater and safer access to the turbines and it maintains motivation among the technicians. Key factors are the safety and reliability of the ship and the fact that the technicians are comfortable and safe - which in itself will generate high motivation.

Staff retention is better, which is a significant advantage. The cost of retraining staff can be high, and there is a distinct advantage to retaining personnel, who have increasingly better knowledge of the specific wind farm maintenance issues.

Robert Trahan: We wanted to design a vessel that would be optimized for the whole lifecycle of the wind farm. Most of our company directors come from an oil and gas offshore construction background.

We have a similarity to the 1970’s where most of the equipment available was not built for the rigors of the North Sea. It took a few years before purpose built bespoke equipment that enabled large scale construction to happen on time and on budget.

The industry requires this improvement to deliver the aggressive 2020 targets set by Government.

To respond to this article, please write to the editor: Rikki Stancich