Powering heritage buildings and districts with solar panels

Berlin’s Reichstag and the Vatican show that heritage is not a barrier to well-designed solar panels

Solar is the new ‘king of electricity’ according to Fatih Birol, Executive Director of the International Energy Agency (IEA). But many cities in Europe with historical centres have been struggling for years to balance heritage architectural concerns with the need and potential of the king of electricity.

The result is that solar generating capacity in city centres is much less than what it could be.        

Photo: Bruno Gaiddon –
PV and Grid Expert at Hespul.org

But Bruno Gaiddon has been working to change that for most of the 20 years he has spent designing and implementing PV systems in France – most recently in Lyon Confluence as part of the Smarter Together project. He works for Hespul, a non-profit founded in 1991 that installed France’s first photovoltaic array in 1992 – which is still in operation.

Just a few minutes into our conversation it is clear that his enthusiasm for solar panels hasn’t waned over the years.

“In many cases, we discovered solar panels are the solution to aesthetic concerns of new buildings in heritage areas.” – Bruno Gaiddon, Hespul

He explains that there are generally three scenarios where heritage rules can conflict with PV systems. That conflict in France means a meeting with a government architect who will give his opinion on any proposals. There is a similar process in many EU countries.

Installing PV as part of a new construction within a heritage zone (within 500m of a classified heritage building)

“What we have noticed is that when building in a heritage zone the first building, designed and conceived by an architect, can be very difficult with a lot of negotiation. But afterwards, all of the buildings (with solar panels) are very easy.

“In Lyon Confluence, which is in the centre of the city, it is quite a flat area and the buildings are seen from the nearby hills. So we see the roofs of buildings. And with the guidance we had from the state it was important to use a really sensitive design and deployment of photovoltaic panels to hide the technical systems like ventilation that were on the roof.”

Solar panels are the solution to aesthetic concerns of new buildings in heritage areas.

On heritage buildings themselves

“I present projects that are indisputable. It is with pleasure that I can talk about these projects which occur in Europe. For me, they are projects that are of such a high quality that no architect can dispute them. And they are very, very simple.”

The Vatican shows off its green credentials with a large PV array – Photo: Bruno Gaiddon

For me, the conference building at the Vatican, a UNESCO world heritage site which has the highest level of protection is the most beautiful installation in the world. The used inexpensive, mass-produced panels in a very simple way the integration is really remarkable.”

“The other building is the Reichstag in Berlin by Norman Foster where he put photovoltaics on the four sides of the building. And it is another example of a remarkable installation combining the old and the modern.

Norman Foster’s renovation of the Berlin Reichstag with photovoltaics seemlessly incorporated into the roof. Photo by Fionn Große on Unsplash

Installing PV on existing (modern) buildings within heritage zones (within 500m of a heritage building)

“When we have projects to install PV on existing buildings in a heritage zone, without any other work, it gets very complicated

Notice how the PV installation follows the same gentle curves and hides the HVAC system on the roof photo: Bruno Gaiddon

“The conception of the installation needs to be done by a team with an architect whose job it is to find a harmonious way of integrating the panels into the building. If the architect doesn’t have a lot of experience it is worth training the architect on what has been done on other buildings with an exceptional architectural heritage.”

The final point from Gaiddon is that timing can also play a role. If a heritage building has been damaged or needs to be renovated there can be an opening even with “very conservative architects.” The fact that the building will change, that it needs to change, is an opportunity to incorporate photovoltaics in a way that shows the transformation from an unchanged heritage building to a heritage building with a modern use and modern elements.