Solar energy is the fastest growing alternative method of electricity generation worldwide, but it is still not an integral part of architecture. Architects must take the lead in integrating PV panels into building designs, argues Zoheir Haghighi in his doctoral thesis. ‘The technical means are there, it's time to apply them,’ he says.

Currently, 25 million households worldwide rely on solar power for power. According to an International Energy Agency (IEA) projection, that number will grow to more than 100 million by 2030. Quadrupling will only be possible if we use a maximum number of surfaces on and around buildings in cities to absorb solar radiation. Generation and consumption should be as close as possible, for example, because transporting energy over greater distances leads to losses. ‘Unfortunately, that doesn't happen, because building designers have too much hesitations,’ Haghighi observes.

Unnecessary replacement or hiding

Building Integrated PhotoVoltaics (BIVP) - is a well-known expression in modern architecture, but what does it really mean, he wondered? A literature review reveals that it mainly stands for replacement: part of a roof or façade is taken out to make room for a solar panel. Analysis of thirty building projects on design decisions and visibility shows that architects rarely try to do anything special with solar panels. On the contrary, they often hide them. That is unnecessary, other projects show. Architect Toyo Ito for example, used solar panels to create a spectacular sculpture in the shape of a dragon's tail in a stadium in Taiwan. Such an application contributed to the success of the design.

Haghighi furthermore had interviews with 30 architects from various countries about the experiences and challenges surrounding PV. He divided them into two groups: one with and one without solar experience. ‘Remarkably, those without much PV experience tend to see it as an alien,' he observes. ‘They don't see it as something like an air conditioner, they see PV as far too complex.’ Doubts about factors such as shading and orientation, as well as supply chain risks and service life proved reason for skepticism.

Those who did have extensive experience with PV, on the other hand, turned out to be particularly enthusiastic about the technology. This was also because they were familiar with the available technical possibilities, Haghighi believes. For example, there are specialized companies that provide customized PV: color, design and size.

Mass customization

Unfortunately, such custom production (still) represents high costs and lower yields. The fact that the cost of a solar panel today is 400 times lower than forty years ago is due to mass production of modules in east Asia. Therefore, it is now time for the next step, argues Haghighi: mass customization for application. Awareness of what opportunities already exist in that area is also crucial. ‘Architects have to take the lead in this. They decide on the building design, which today is tied to BENG standards. Designers should apply PV as they do with other service units such as air conditioning, radiators and boilers.’

Why not use a roof of photovoltaic tiles instead of a panel here or there? This innovation by Elon Musk ("Tesla Solar Rooftiles") never broke through, but it could still happen if there is enough demand. Is there no room on the roof? There are plenty of options for integrating PV into the facade or around a building. There are transparent PV panels, folding, double-sided, PV curtains and even PV chimneys - the Delft spin-off Pholtaire – co-founded by Haghighi – is working on them. Isn't the price of such innovations a problem? ‘Let architects get over their fear and incorporate innovations into their designs,’ says Haghighi. ‘The possibilities are there, they only become big if something is done with them.’

Publiced: December 2022

More information

Zoheir Haghighi received his doctorate on 7 November with his dissertation Architectural Photovoltaic Application.

His defense can be viewed on collegerama.

Z. (Zoheir) Haghighi

Visit the staff page of Zoheir Haghighi here.