Two people on the roof of a branch with solar panels

Neckarsulm, 3. May 2023

International Sun Day – Questions About Solar Energy for Toni Thudium

Toni Thudium is the head of the Energy Systems team at Schwarz Immobilien Services and is responsible for the development of holistic strategies for the safe, efficient, and sustainable supply of energy to the Schwarz Group companies. On International Sun Day, he talks about the difference between renewable energy and gray energy – and about the reasons why some stores in Germany are relying on North Sea winds during the night.

Why is the shift to green energy so critical in the context of climate protection in the EU, and what role does renewable energy play here?

Toni Thudium: If you take a closer look at EU-wide greenhouse gas emissions from 2020, you will notice that around three quarters can be attributed to the energy sector – corresponding to around 2.5 billion tons of CO2 emissions. This leads to a corresponding amount of leverage on the EU climate targets. To put it another way: without a shift to green energy, climate neutrality by 2050 is an impossibility.

That is why the EU is working on decarbonizing its energy system, reducing the proportion of fossil fuels while increasing the amount of renewable energy sources.

What this means for electrical power is that as much electricity as possible is to be gained from renewable energy, such as sun, wind, biomass and the geothermal sector. The popular term for electricity generated using these methods is “renewable energy”. Power generated from fossil fuels such as coal, gas or oil is referred to as “gray” or “conventional energy”.

The key difference is that the generation of renewable energy is much more environmentally friendly, producing little or no emissions or other pollutants.

The companies of Schwarz Group procure 100 percent* of their electricity from renewable energy sources. Why is it so important for them to be generating their own electricity as well?

Toni Thudium: Yes, we have been procuring 100 percent* renewable energy since the 2022 fiscal year. However, we have done much more than just that.

One of the first, crucial steps was to see where we are using power and where we can save energy. Ideally, we would not need to use any electricity – meaning that we don't need to generate any either. Energy management in accordance with ISO 50001 [A1] is helpful in this respect.

As companies of Schwarz Group, we build and operate numerous properties, so it was not difficult to see the next step. We worked with division experts to establish how many properties were suitable for electricity generation and could use that power themselves, and the conditions required for this. One of our approaches is to use photovoltaic systems – on-site energy production. We obtain energy from the sun on top of our stores and logistics centers, and at other locations.

In the 2021 fiscal year, our photovoltaic systems covered an area of 1.6 million square meters – equivalent to around 222 soccer fields. This allowed the companies of Schwarz Group to generate about 196 million kilowatt hours of electricity from the sun.

In the coming years, we will continue to add to the number of photovoltaic systems on our properties, allowing us to produce even more solar power.

Does that really mean that there will be a photovoltaic system on every store?

Toni Thudium: Fundamentally, that’s a lovely thought – but when planning and implementing the use of renewable energy, it’s important to understand that these projects make a particularly important contribution when they perfectly suit the environment and the prevailing conditions. In concrete terms, I think it makes less sense to run a photovoltaic system in a location where the sun shines year-round if the roof area is in the shadow of adjacent buildings or trees, for example. We could definitely make better use elsewhere of the resources expended here. Especially with older buildings, there are often structural reasons for not installing a photovoltaic system.

That is why we, the companies of Schwarz Group, have conducted detailed investigations of our properties. This means that we will install a photovoltaic system on every suitable new building, while considering what options we have for adding a photovoltaic system to our existing properties.

You have already mentioned it: We need the sun to shine for the idea of self-sufficiency using solar energy to be a success. To what extent does the generation of our own electricity from photovoltaic systems depend on the weather? What do we do if the sun doesn't shine?

Toni Thudium: That’s a good question. There are already plenty of locations that can provide all the energy required with a photovoltaic system on sunny days, so there are times when they do not need any electricity from the national grid. This means that the location is powered purely by solar energy, which is “harvested” with the photovoltaic system on the roof and supplies electricity to the linked energy consumers, such as chiller equipment, electrical charging points or lighting. Of course, we have to get power from the grid at other times, especially overnight.

We have been relying on renewable energy since 2022 fiscal year and we are continuously enriching our energy portfolio with a range of products – including PPAs, Power Purchase Agreements.

A PPA is a contract between an electricity producer and an electricity consumer for a specified quantity of electricity. The purpose of a PPA is to finance and support the construction and operation of power generation plants – especially for renewable energy – by providing electricity producers with a long-term, reliable source of income. Electricity consumers can also benefit from more predictable energy costs.

The PPA “Kaskasi”, recently concluded between Lidl and Kaufland in Germany and a North Sea wind farm, is a good example of such a contract. It can be viewed as a blueprint for how to do this and shows just how versatile our electricity generation can be in the future. We do produce our own power on top of many stores – however, this only works during daylight hours and if the sun shines for long enough; we need another solution at night. This is where the North Sea wind comes into play, as it can be relied upon to blow at night. 

How do you think that the companies of Schwarz Group can support the energy transition in Europe?

Toni Thudium: The companies of Schwarz Group are already involved in supporting the construction and operation of renewable energy systems in Europe. Every day, our colleagues from the Energy Systems area are also working on new ways to meet the responsibility that we bear as a company. They are focusing on decentralized, renewable electricity generation and innovative technologies, such as battery storage. These will dovetail into holistic energy concepts. We share our experiences with a range of stakeholders from politics, the business sector and science. The involvement of the companies of Schwarz Group is making a contribution to the success of the energy transition.

*Excluding purchase agreements that the companies of Schwarz Group cannot influence, such as those for individual leased properties with a binding electricity procurement clause. You can find more information here.

Would you like to find out more about the PPA “Kaskasi” and renewable energy supplied from the North Sea? You can find more information on this topic here.

Portrait of Toni Thudium
solar systems