SCOL is short for Self-Contained Offshore Lighthouse.
The SCOL unit is based on battery and solar power technology with remote operating and monitoring capabilities. These units are used during dismantling of offshore installations to mark the position of elements that are without power, and they are specially designed to withstand the harsh winter conditions of the North Sea.
We have several units already installed in the North Sea. Some references include:
-BRENT BRAVO & DELTA
For CONOCOPHILLIPS we have had 11 SCOL units for different areas, including Ekofisk, on Norwegian, German and British sectors.
The units are made up of a lamp, an active radar beacon and a control panel. It is powered by twelve solar panels with battery banks. It is constructed to withstand harsh conditions over long periods. It is designed to operate for 4 years without maintenance in the North Sea.
Each unit contains a battery bank with sufficient capacity to maintain operation throughout the dark winter months in the North Sea.
The units are also equipped with a control unit and remote communication capabilities using satellite and GSM technology. This allows 24/7 monitoring and control of the unit from ComPower. Therefore, there is no need for client monitoring.
The units are mounted by first welding or bolting a circular base plate with a centered pole onto the installation that is to be marked. The unit itself is then lifted onto the base plate by crane or helicopter.
The lifting set utilizes a lifting ball that requires no handling for hooking on or off so that the unit can be quickly and easily replaced for maintenance. One simply lifts off the SCOL unit by helicopter or crane and replace it immediately with the spare. The SCOL unit is then sent to ComPower for service. When finished, we send it back to the client for them to either install on a different platform or to store as a spare.
The unit is omni-directional, which means that you do not need to take into account that solar panels should be pointing towards the south, which significantly simplifies installation and reduces the possibility that the device becomes stuck from corrosion.
We can customize our units to fit our client’s needs. We can for example offer various sizes or additions such as foghorn. Just contact us with your specifications and we can adjust the units to fit your needs.
ComPower’s SCOL structure is certified by DNV to be able to carry the maximum foreseeable wind force that may occur with a return period of 100 years. This also covers forces in both the ultimate limit state and lifting condition.
This is based on 16 different standards, including:
-DNV-GL 2.7.3 Portable Offshore Units
-DNV-GL 2.7.1 Offshore Containers
The SCOL units are designed for 15-20 years offshore operation. They can be installed on the main deck and be the nav. aids systems needed until the main deck is removed. When the main deck is removed, one of the SCOL units is installed on the jacket and the other one may be stored as spare onshore.
This solution gives the client time to adjust their decommissioning plans if needed as the IALA requirements are fulfilled at all times.
It is also cost saving as the jacket does not have to be removed immediately, but can be removed when there are available vessels and can also be taken together with other similar operations in the area.
We recommend service intervals every 4 years. As we can see from the Yme removal in the image above, one SCOL unit was put on the platform leg, while the other was taken back to shore. The unit taken back to shore can be stored as a spare, used either for other offshore installations or for service intervals.
The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) requirements and recommendations are followed by all lighthouse services. This means that the Aids to Navigation supplied must be according to their requirements or better.
It is important to note that the IALA calculation of solar panels and battery back-up is based on average weather conditions over many years and do not support weather conditions deviating from the standard.
ComPower has monitored SCOL Aids to Navigation offshore for more than ten years and we have concluded that the IALA standards do not fulfil the requirement for Aids to Navigation in the abnormal winter weather we have had the last 5-6 years. Hence our calculations are far more conservative to comply with the lighthouse services and our clients need for Aids to Navigation offshore.
This project was initiated in 2008 when ConocoPhilips first contacted us with their requirement. After a number of challenges in the concept and design phase, we found in early 2009 what we thought would be a good and suitable solution.
We proceeded to establish contact with the sub suppliers needed for the realization of this project. Local suppliers have played a central role in the mechanical implementation of this project. We have third party certification of construction and strength calculation, including lifting set.
The actual production of the units started in March 2009, and it was an intensive process to deliver within the given time frame. Thanks to a close collaboration with customer and suppliers, in addition to a solid effort from our very skilled employees, this project was a success.
In the picture: Complete SCOL unit with satellite communication.
In the picture: SCOL units installed next to the Ekofisk tank. (Image by ConocoPhillips)
In the picture: Three SCOL units installed next to Ekofisk tank. (Image by ConocoPhillips)
In the picture: SCOL unit being installed on the remains of a booster platform. (Image by ConocoPhillips)