Researchers modelling a floating solar farm
A floating solar farm: This model is equipped with sensors that gather wave information and data on both the movement of, and stresses on, the moorings and coupling points. Photo by SINTEF

Researchers to test a solar farm at sea

The sun shines just as much out at sea as it does on land. There are also no restrictions on area use and seawater even helps to cool the solar panel technology. It’s only a matter of time before the first floating solar energy farms are installed at sea.

There are many benefits to exploiting ocean-based solar energy. Valuable areas on land can be protected, and marine installations may represent a green energy alternative for overpopulated towns and cities. Offshore installations make it possible to utilise sea areas that are currently underused.

Moreover, ocean-based solar energy can provide the power generation sector with an extra boost. Not only does it offer almost unlimited spatial area for the installation of solar infrastructure, but the seawater provides a natural coolant for the solar panels, which in turn increases efficiency and optimises operations.

“This was a very special project for us”, says Nuno Fonseca, a Senior Research Scientist at SINTEF. “We’ve never before tested a design involving so many modules. However, the development of water-based installations is not without challenges.

Infrastructure needs to be designed to withstand dynamic stresses caused by waves, wind and currents, and at the same time generate energy that competes with other energy sources on price. This is where our engineers and researchers come into play”, he says.

“Our task is to resolve the commercial challenges by studying and testing the installation designs”, says Fonseca. “Our aim is to develop efficient and cost-effective solar-energy engineering systems”, he says.

Recently, the research team conducted a model test which demonstrated that floating solar energy farms have the capacity to withstand such high stress loads that it may be feasible to deploy them far out at sea.

Experience from model tests

A report produced by Det Norske Veritas (DNV) has stated that if we are to achieve the targets set out in the Paris Agreement, solar energy has to become between eight and ten times more prolific in the market by 2030 than it is today.

If we are to reach these targets, we have to challenge our traditional systems. Researchers at SINTEF have now completed tests in a marine basin using a 1:13 scale model of a floating solar power facility. This was made possible as part of a contract research project commissioned by Moss Maritime and Equinor.

The anchors system of the new floating solar farm

Here, the researchers are testing an anchoring system that will give the installations enough freedom to cope with the waves. The purple sensors measure the movements. Photo: SINTEF

The model was equipped with sensors that gathered wave information and data on both the movement of, and stresses on, the moorings and coupling points. Moss Maritime then used these data to calibrate its numerical model, which will later be applied in the design and optimisation of full-scale installations for Equinor.

“This was a very special project for us, as we’ve never before tested a design involving so many modules. Here the model consisted of a total of 64 floaters, all coupled together”, says SINTEF researcher Galin Tahchiev, project leader for the model tests..

“The test demonstrated that we’re well equipped to handle complex installations of this kind”, he adds. Senior Researcher Fonseca explains how humans have accumulated centuries of experience using traditional sea-going structures, but that solar farms is entirely new.

“This is why the model testing is so important”, he explains. “The systems involved are complex and they behave in complex ways. Model testing in the marine basin enables us to generate reliable data about the behaviour of the design under realistic conditions”.

Taking the concept out to sea

“Our collaboration with Moss Maritime and Equinor is innovative because these companies are looking into the possibility of installing facilities of this kind in exposed locations”, says Øyvind Hellan, Research Director at SINTEF Ocean.

“This new testing is revolutionary because the design concepts that exist today are mostly intended for use on inland lakes and hydropower reservoirs, and many of them will not be equipped to handle ocean waves”, he says.

SINTEF Ocean is also involved in Equinor’s pilot project that is currently testing a floating solar power facility off the island of Frøya in Trøndelag. The ultimate aim here is for researchers to expand the pilot into a full-scale research and development facility closely linked to the SINTEF ACE aquaculture laboratory and the future Ocean Space Centre.

“One of the main benefits of this will be access to more sites in the immediate area, and the potential for different projects to complement each other. This is one of our strengths”, says Hellan.

Cross-disciplinary collaboration takes us forward

Researchers want to continue with their model testing of floating solar farm facilities in exposed locations at sea. The team also intends to work together with colleagues who can examine the broader societal impacts of such facilities and the effects they will have on the external environment.

“Norwegian industry currently enjoys a strong and unique position as a world-leader in the fields of renewable energy technology, offshore technology and marine operations”, says Hellan.  “The country has an extensive knowledge base and SINTEF Ocean can offer the technology we need to promote growth in this market”.

SOURCE:“8 times more wind and solar power needed by 2030 to help meet Paris climate target, DNV GL finds”. From DNV’s Energy Transition Outlook, 2019.