Frequently Asked Questions
What is the yield compared to ground-mounted PV or other FPV systems?
The Ocean Sun technology provides a ~10% increase in yield compared to air-cooled PV systems, according to an article by Selj et al. presented at the 36th European Photovoltaic Solar Energy Conference and Exhibition.
Are the modules permanently fixed (e.g. glued) to the membrane or can they be removed?
Male keder strips are welded on the membrane. The modules are fitted with maritime grade aluminium female keder, and are slid into position and secured by crimping. This facilitates easy installation and replacement of modules.
What testing has been done on the panel attachments to ensure that it lasts for the expected lifetime?
There are no significant stresses on the attachments between the module and the membrane as the modules are supported by the membrane, and are not subject to horizontal forces. Testing shows high redundancy in the strength of the welded keder.
Given that the PV modules are unframed, will micro-cracking occur during wave action and what effect will this have on yield? How can you prove this to an independent engineer?
The membrane provides the optimal environment and support for the modules, in regards to module stresses. Due to the consistent water-cooling, the panels do not experience any daily thermal cycling. In addition, there is no wind vibration and no snow load.
Mounting the backside of the modules directly to the membrane allows for sufficient support with insignificant flexing and pressure points. This enables workers to step unobstructedly on the membrane and directly on the panels without damaging the panels. Ocean Sun holds several independent reports on the panels from a system installed off the coast of Norway. These panels have for several years endured varying harsh Norwegian weather. From these reports researchers concluded that after 3 years, the panels had 0% degradation from any source. This is documented by the Institute for Energy Technology (IFE), amongst others.
Can the membrane and modules handle snow and ice loads?
Our system is tested with moderate amount of snow and ice in the Norwegian fjords without problems. However, we normally seek locations without thick ice.
What is the module tilt?
The modules will lie flat on the membrane. The benefits of this are:
- The thermal dissipation will result in 10%+ increased efficiency that will outweigh the added yield from tilt in high latitude locations.
- Wind drag is minimized.
- Our installation procedure is both quick and low cost due to our patented locking mechanism.
- Due to the even distribution of weight when the module rests on water, it is possible to walk on the module, reducing space redundancy.
What kind of modules are supported?
The Chinese manufacturer GCL System Integration produces the customised 60-cell, dual-glass Ocean Sun module with front-mounted junction boxes. The modules are TUV tested for our application, following standard GCL warranties.
How is rainwater handled?
The OS-75 comes equipped with 9 bilge pumps placed on the membrane to ensure effective handling of water on the membrane. The pumps are dimensioned to handle extreme precipitation events and potential sea spray during storms. The 9 pumps also ensure redundancy in case of any pump failure.
How do you transport the hydro-elastic membrane?
The membrane for a 660 kWp floater can be easily shipped in one 40 foot container.
How are operation and maintenance conducted on the floating system?
The hydro-elastic membrane is walkable, and due to the patented mounting systems for the panels, it is also possible to walk on the panels without damaging them. Thus, operators can easily access the whole system and any O&M is efficiently conducted at site.
What is the area required for installation?
The OS75 floater provides up to 640 kWp installed capacity per floater with an area of approximately 0.44 ha.
This is equivalent to 1.4 MW installed capacity per hectare for an individual floater. For larger multi-ring systems, some space is required between the floaters to provide access to O&M.
Are there videos from an Ocean Sun system?
Yes, in the footer of the webpage, you will find the link to our Youtube Chanel. Her we upload videos from the different Ocean Sun systems from around the world.