ALDI SUISSE carried out what is probably the most ambitious and also one of the largest solar energy projects in Switzerland: in just over a year, 59 roofs between Romanshorn and Geneva were fitted with photovoltaic systems. We were responsible for the planning, financing and implementation, and have been responsible for the smooth operation of the systems ever since.
‘TODAY FOR TOMORROW’ is ALDI SUISSE’s sustainability slogan, meaning that the retailer offers quality in its stores at the best price, but also takes its responsibilities seriously: towards stakeholders, society and, of course, the environment.
The solar project is also about sustainability and cost effectiveness: photovoltaic systems with a total output of up to 15,000 kWp were installed on the roofs of 59 ALDI SUISSE stores. In total, the solar panels produce around 14 million kilowatt-hours of electricity per year, equivalent to the consumption of around 5,300 households. This allows the retailer to make a valuable contribution to Switzerland’s sustainable energy supply – and at the same time significantly reduce its operating costs.
A visit to ALDI SUISSE in Villmergen
The Villmergen store is a stone’s throw from Wohlen railway station. The roof offers an unobstructed view of the distinctive feed silo towers. ‘The rapid pace was possible because we worked with ewz to develop a solution that is highly standardised. Our stores have a very standardised layout – we also adopted the idea of a ‘modular system’ for the PV systems. This made implementation easier and will also bring efficiency gains in terms of maintenance,’ says Fabian Gloor, Procurement and Environment Manager at ALDI SUISSE.
The collaboration with ewz and its subcontractors was extremely successful: ‘It wasn’t easy to develop this kind of standardised solution, but we managed it together.’ Gloor’s view of the dynamic power control of PV systems is particularly positive. What’s this about? The electricity produced by the PV system is primarily used directly in the ALDI-SUISSE store to cover self-consumption. If the store uses less electricity than the PV system produces, the excess electricity is fed into the grid. The building’s electrical connection therefore needs to be tailored to the maximum output of the PV system (e.g. sunny Sundays with maximum production and small self-consumption). However, as this situation is extremely rare and only temporary, upgrading the building connection would be disproportionately expensive. Instead, the output of the PV system is regulated at all times in such a way that the feed back into the grid never overloads the existing building connection. If the store’s consumption increases again, the output of the PV system is automatically increased. In this way, ALDI’s self-consumption can be optimally covered using PV electricity.
The electricity from the systems is used by the stores themselves, which – like all retailers – use a lot of energy due to the large number of chiller cabinets, the oven, heating and lighting. ‘We have already been able to reduce our consumption massively over the past 15 years,’ says Gloor. Solar power is also used, where available, for the e-charging stations next to the stores and any excess fed into the grid.
ALDI SUISSE has concluded a contracting agreement with ewz
Simply put, ‘We provide our rooftops and use solar power wherever possible to cover our electricity consumption directly in the store,’ says Gloor. The PV systems belong to ewz, which is also responsible for maintenance, billing and replacement. The ‘full service package’ also includes the overall coordination of the project, obtaining building permits, remote monitoring and the use of residual power.
Our project manager Roland Jucker has been with ALDI SUISSE from the very beginning. ‘The idea of fitting as many roofs as possible with a standardised PV solution was a visionary one,’ he says. Jucker is particularly proud of the fact that the installation could be carried out during operating hours. ‘After business closed, we had to disconnect from the grid for 30 minutes – that was the only interruption.’
Christoph Deiss, Head of Energy Solutions at ewz, says: ‘I’m not aware of another project like this one in Switzerland. Together with us, ALDI SUISSE is making a valuable contribution to protecting the climate.’ Christoph Deiss emphasises ewz’s extensive experience: ‘We have been using photovoltaic technology for over 30 years – we have been a solar pioneer from the very beginning.’ Its extensive expertise and many years of experience enabled ewz to prevail in the tender against around a dozen competitors. ‘ewz is a Swiss company with sites in Zurich, the Grisons and Vaud,’ emphasises Christoph Deiss. ‘Thanks to our regional operations teams, we are able to guarantee maximum security of supply and short response times.’
- Planning, implementation, financing
- PV contracting over 20 years
- Operation of PV systems
- 45,000 PV modules
- 140 Inverters
- 15,000 kWp output power
- 14 GWh of annual solar power production
- 55–60 per cent self-consumption on average
