Photovoltaic plants have long ceased to be pure yield objects. As the solar share of power supply grows, so does operators' responsibility for the overall system. New rules for plant control — curtailment during grid congestion as well as Germany's "Solarspitzengesetz" (solar peak law) — make technical operations more complex than ever. Conventional monitoring solutions reach their limits here.
Beyond the green light
Conventional monitoring often shows a seemingly fault-free plant while creeping performance losses go undetected. The digital twin starts exactly here: instead of working with rigid thresholds, it represents the plant as a high-precision mathematical model and compares real performance in real time against a dynamic target value. All component data flow into this model — from the datasheets of the modules and inverters through cable cross-sections to the wiring diagrams.
"With the twin we look back at how the plant has behaved — and forward, to recognise in time how performance is developing."— Oliver Skadow
AC- and DC-side modelling
Together with Dr. Thomas Littmann, the methodology has been continuously developed since 2016. Initially the focus was on the AC side — the inverters. By now the digital twin also maps the DC side down to string level. The modelled forecast curve is overlaid on the actual yield curve; deviations thus become immediately visible — including creeping processes such as slowly loosening plug connectors.
Proactive maintenance and forward-looking operation
A complementary analysis tool compares target and actual values and predicts which type of fault is involved. This enables proactive maintenance that minimises downtime and secures yields. Irradiation data, module degradation, inverter ageing and yield forecasts all feed in. Across entire portfolios — in Germany, Italy and Spain — this approach can be consolidated into a unified, forward-looking operations management.
Why this is decisive now
With the Solarspitzengesetz, inclusion in redispatch and increasingly negative electricity prices, technical operations alone are no longer enough — the business model has become market-driven. The digital twin combines technical monitoring with commercial control and delivers concrete decision support: for instance for the investment in battery storage or the optimisation of PPA structures. This creates a holistic tool for the modern operation of ground-mounted PV and hybrid energy parks.
See what no monitoring shows.