It may be about as grey and gloomy as you’d expect it to be in this part of the world in the middle of December, but even the weather can’t take the smile off Giuseppe Cecere’s face today. The Head of Building Service Engineering at Allreal is in such a good mood because the installation of the solar power system on the roof of the commercial building at Bändliweg 21 in Zurich Altstetten is finally well underway. For a long time, supply issues made the exact start date for this project a mystery.

“The system installation was originally scheduled for early autumn because the weather would have been a bit nicer. The conditions aren’t ideal for the people working on the roof 25 metres above us when there’s strong wind and rain,” says Cecere. But it was difficult to get hold of the materials for the structure supporting the system to start with. And then it ended up taking longer than expected to obtain approval from the authorities. But the specialists have been hard at work on site for a good week now. Having already installed the supporting structure, they’ve even started positioning the solar panels across the roof surface spanning some 1,340 square metres.

“All kinds of tradespeople are working up here on the roof with us solar specialists to get the system installed, including an electrician, plumber and roofer,” says Chris Wegmüller, the Project Manager from Solar21, Allreal’s energy partner. “We’re taking care of the installation itself as well as the ongoing running of the system, which involves buying the solar power from Allreal and selling it to the building tenants. But that’s not all – we’re also responsible for analysing and optimising energy consumption at the property. All of that makes us the ideal partner for Allreal all round,” explains Wegmüller.

Production of up to 60% of the overall power required per property from solar energy

Over the course of the day, more and more solar panels are skilfully lined up one after the other, each with 108 monocrystalline cells. By the time the installation work is complete in four weeks or so, the team will have installed around 222 solar panels in total ready for the system to officially go live in spring 2023.

From that point onwards, the solar power system at Bändliweg 21 will provide a good proportion of the overall power required at the commercial building with total floor space of 18,642 square metres. “Exactly how much of the overall energy consumption can be covered by solar power produced on site varies from property to property,” explains Giuseppe Cecere. But the figure is usually somewhere between 30 and 80% of the total energy required. This percentage depends on how high the energy consumption is at a particular property and how much space is available for the solar power system, which determines how much solar power can be generated. The output of each solar cell has an impact too, with 415-Watt solar cells currently being used. “With the technology evolving all the time, we can safely assume that the performance will improve drastically over the coming years and decades,” says Cecere.

All of the 33 systems being installed by Allreal in line with its commitment to sustainability are expected to last for at least 25 years. That much is covered by the manufacturer’s performance warranty. “It wouldn’t make environmental or financial sense to replace a solar power system before it has reached the end of its service life purely in response to newer, more powerful systems having been released. Just think about the energy and resources required to produce the solar cells and the rest of the system,” explains Cecere.

Considerable carbon reduction with solar power

Solar power systems catch sunlight and convert it into usable electricity. Unlike standard power stations, they are completely climate neutral since they don’t release any carbon emissions whatsoever. “The system on the commercial building at Bändliweg 21 alone will allow us to cut out around 9,800 kilograms of CO2 each year once it’s up and running. The already planned solar power systems will thus contribute to reducing the CO2 emissions from Allreal’s portfolio of yield-producing properties. So of course we’re not hitting our target of being fully climate neutral by 2050 just yet, but we’re definitely taking an important step in the right direction,” says Giuseppe Cecere, who is satisfied with the progress so far.

Important investment in the future

By 2024, Allreal will have invested around CHF 7.5 million into installing solar power systems across its property portfolio in total. Around 20% of this investment will have been covered by government funding at the national and cantonal level. It may be a number of years before Allreal starts to see a financial return on this sizeable investment, but the positive environmental impact is immediate.

“Our priority is to sustainably optimise our portfolio and investing in climate-neutral energy generation is an obvious way to do just that. Given that we’re currently seeing the huge impact power shortages can have on our everyday lives, we’re feeling even more confident that we’ve made the right decision by investing in solar power systems and gaining a certain degree of independence when it comes to energy,” says Cecere to finish up.

By this point, the work on the roof at Bändliweg has finished for the day and everything has gone dark up there. The workers will be busy here for a few more weeks until the system has been fully installed. By February 2023, the system will be supplying the tenants in the commercial building with climate-neutral power.

As of the end of 2022, Allreal had installed solar power systems at four of its properties. The remaining 27 installations will be complete by the end of 2024. All the other yield-producing properties are being reviewed regularly to determine their eligibility for a solar power system. Allreal ensures that a solar power system is included in the plans for any new-build projects where possible.

By relying so heavily on solar power, the company is taking an essential step towards the target to reduce carbon emissions.