How far along are you in the implementation process?

The system is already producing electricity. We are in the final coordination phase with the metering point operator, the grid operator and the direct marketer. We are currently optimising the processes to ensure precise billing of the surplus feed-in. This will be followed by final acceptance, which is planned for the end of the year. Dividing a plant into two areas and designing it as a self-consumption plant as well as a leasing and investment plant requires precise planning and good cooperation between us, the buyer, any investors and also the metering point and grid operators. Unfortunately, a number of challenges have set us back somewhat in terms of time for this major project.

What were the challenges?

The shorter daylight hours in the winter months made the work on the roof considerably more difficult. In addition, as is not unusual at this time of year, we had to take into account sickness-related absences in the team. Of course, these factors are nothing new and are always taken into account to some extent when planning for the bad weather months, but the weeks of rain in spring led to major delays that were neither foreseeable nor completely predictable. Construction phases had to be split up due to the weather. This affected subsequent processes and other projects running in parallel. Supply bottlenecks at supplier companies and very high demand on the PV market were also a factor. As this project was not just about erecting the PV system, the construction sector, deliveries and logistics also had to be taken into account. Added to this were the booming PV enquiries from grid providers throughout Germany, over which we have little influence as a general solar company, but without whose approval we could not make any progress. The plant was originally due to be connected to the grid in April, but unfortunately it ended up being the end of June.

What do your solutions look like?

In order to rebuild the transformer and the medium-voltage system, we had to take the entire operation at the Dortmund site off the power grid and continue to supply it via a 600 kVA emergency power generator out of consideration for ongoing production and to minimise the outage as much as possible. Our team worked around the clock to ensure that production could restart smoothly at the beginning of the week.
Renovating a roof area of this size is an enormous challenge. With constant rain and storms, it was also an unprecedented experience for us. We could only work in sections because the substrate had to be dry for laying the FPO membranes. Some parts had to be elaborately protected with tarpaulins. This meant additional work. In addition, a gravel covering had to be removed from the approximately 1,000 square metre flat roof of the office area before we could start with the actual renovation. All the connections to the many strip lights and skylight domes on the roof had to be replaced. During the work, we discovered that the existing drainage system was inadequate, so we had to install additional gullies and wedges to channel the rainwater away.