As electricity prices have skyrocketed and as a step in the development towards more sustainable buildings, solar electricity is being installed to an ever greater extent. In 2021, the number of solar cell installations installed increased by 46 percent compared to 2020, according to statistics from the Energy Agency. Part of the market that is on the rise is building-integrated solar power, which is becoming a natural part of the architectural design.

Rickard Nygren is an architect and sustainability specialist at White and works both with traditional solar panels and building-integrated solar cells in several projects.

- A challenge for the industry is to change the idea of ​​what facade material is and above all what it does. Solar cells are a facade material that not only passively dresses up the house or gives it color, but also actively contributes by generating electricity. To drive development forward, we must dare to take new steps, says Rickard Nygren.

Buildings that contribute
From January 1, 2022, Sweden has a new law on climate declarations for buildings that are constructed, and knowledge of the climate impact of solar cells is still in its infancy. During manufacture and installation there is a certain load, but in a longer perspective they pay back on their footprint. Climate declarations make it clear what role solar cells play and to what extent they can add a positive climate benefit.

- Buildings must give something back to the place they are located. In this case, it happens by the solar cells paying back in kilowatt hours and contributing renewable energy to the system as a whole, says Rickard Nygren.

In connection with record high electricity prices, another argument for producing own electricity has emerged. Self-produced electricity provides increased control and free electricity once the solar cells are in place. Property owners become less sensitive to power outages and those who can also charge electric vehicles make the most cost-effective use of them.

- The more buildings that have their own solar cells, the less vulnerable we become as a society. If they are also integrated into the building, the chances are greater that they will enter more houses than they would otherwise have done. Solar cells are an obvious building block in a sustainable society – the potential is enormous, says Rickard Nygren.
Function meets form
One of the most noticed projects with building-integrated solar cells is the House of Choice in Solna. The house is Scandinavia's most energy-efficient hotel building and is covered with a total of 2,500 square meters of solar cells. With these, the building can produce more kilowatt hours than it uses in a year - a so-called plus-energy hotel.

At House of Choice there are three types of solar cells – standard modules on the roof, integrated in the glass roofs of the light gardens and integrated in the entrance facade. The solar cells on the roof give rise to the saw-toothed profile of the gables. In the glass roofs, there is varied sparseness and denseness to shade and reduce the need for cooling, but also in patterns to follow the character of the interior. The facade has three panel types. One with a frosted surface, one with a grooved surface and one with the same color as the window frames and sunshade. They follow the design idea of ​​the other facades, where smooth and grooved surfaces alternate. The way the different panels reflect the sunlight means that the facade is experienced differently depending on whether it is sunny or cloudy, what time of day it is, whether you see it walking along the street or standing directly in front of it.

- At House of Choice, the solar cells are not only well integrated, but add value to the architecture. It simply gets better with them. Without the panels, the house would have been less expressive, says Rickard Nygren, architect

In order to optimize a building's solar efficiency, there needs to be an idea of ​​how sunlit surfaces can be used right from the first sketches. White has developed digital methods that make it possible at an early stage to produce illustrations and numbers that tell what potential a building has for solar cells. In general, there are many factors to take into account at the beginning of a process, but the estimates that the tools provide speed up the interaction between different members of the work group and make it easier to get solar cells into projects.