Danish collaboration brings colour to tomorrow’s solar rooftops

Rooftop solar PV systems of the future needn’t all look the same – a research team in Denmark is exploring innovative ways of creating cells that can come in different colours and patterns, and be just as effective.

The team, whose members include experts from the Technological University of Denmark (DTU) and the Danish Technological Institute (DTI) along with several other enterprises, aims to have these cells incorporated into rooftops and building facades so they are not visible and can be adapted to suit any structure.

The idea of colouring solar cells isn’t a new one; different methods of doing so have already been tested, both in Denmark and elsewhere abroad. The problem, however, is that colouring solar cell modules significantly reduces their capacity to capture sunlight.

Leveraging the wealth of expertise that each project partner brings to the table, the Danish team believes it will soon solve this.

“Energy consumption in buildings accounts for nearly 40 percent of the total energy consumption in Denmark, and integration of solar cells in building materials is therefore increasingly important in the target to become independent of fossil fuels by 2050,” DTU Fotonik’s Peter Poulsen says in an article on the university’s website. 

According to Poulsen, Danish Solar Energy Ltd, a project partner, has developed a method for manufacturing coloured solar cell modules. The modules are installed behind a special transparent film, which hides the cells and has little impact on their performance.

The film, meanwhile, can be coloured to suit whatever design is desired.

“And this is the method which we’re now trying to refine through our research,” said Poulsen, who heads the research portion of the project.

If researchers are successful, PV arrays would no longer need to resemble the same, boring boxy blues and whites. They can be adapted to the different requirements of any type of building, as well as to suit the requests of different customers.

With architects also involved in the research project, how these solar panels look in terms of building aesthetics will be taken into consideration.

“Imagine a company logo with built-in solar cells, so that the logo produces energy together with the rest of the roof without the solar cells being visible. This is what we would like to achieve. The aim is to be able to colour solar cells so that they are similar to tiles, slate, and patterns, and are adaptable to virtually all buildings,” Poulsen said.

Additionally, research will also consider combining colourised solar cell modules with insulation to help prevent energy loss.

Project solutions are being tested in a new solar laboratory built at the DTU Risø Campus, where researchers and industry leaders are given access to develop, build and test solar modules of all types and sizes.

According to Poulsen, competition isn’t the name of the game when it comes to developing inexpensive solar cells. As concerns over climate change grow across the globe, there is an increasing need for a more cohesive and collaborative effort to find the best, greenest and most cost-effective method for energy generation.

It is only through the combined effort of the many that these solutions can be found, and quickly.

“In Denmark, we cannot compete on making inexpensive solar cells. However, we can contribute to ensuring the technological solutions of tomorrow when it comes to building-integrated solutions,” Poulsen said.

“We have some strong companies and extensive know-how, which can put us at the forefront when we work together. And now we also have optimal conditions to test the solutions in our new state-of-the-art laboratory.”

Apart from DTU, DTI and Danish Solar Energy Ltd, the project also involves Rockwool, Solartag, Tegnestuen EFFEKT and SolarCityDenmark. 

The project is supported by the Energy Technology Development and Demonstration Program.

The new coloured solar cell modules are expected to be ready by 2020.