Marc Hauser

The Performance Ratio (PR) is one of the most widely used and most frequently misunderstood indicators in solar asset management. It appears on nearly every dashboard, yet its interpretation is anything but straightforward. Used correctly, PR is a powerful lens into the long-term health of a plant. Used incorrectly, it can lead to misguided investments, unnecessary site visits, and missed real problems.

This article explains what PR really measures, why 100 % is impossible, and how to use this indicator effectively, whether you are an asset manager tracking a portfolio or a performance engineer investigating losses.

Theoretical power is a fundamental pillar of performance analysis on the Novasense Portal. It represents the calculated output of a solar plant based on weather conditions and the technical characteristics of the plant. Two approaches coexist for calculating it: a physics-based model, comparable to a detailed simulation, and a machine-learning model that relies on the actual historical production of each inverter. The improvements presented in this article mainly concern the physics-based model, which is the most widely used modeling method on the Novasense Portal.

The share of solar power in the Swiss and European electricity mix keeps rising. This growth requires precise coordination between grid operations, electricity production, and market integration, based on a fundamental grid principle: at every moment, total production must equal total consumption.

Flexibility is therefore essential. Active power control of solar plants contributes directly to this balance. As always, Novasense focuses on transparency in these complex processes. The Novasense Portal now delivers a precise calculation of unused solar power caused by active power regulation.

Many new solar plants commissioned in recent years fail to meet performance expectations. The reason? Strings that are too short. How is it possible that many well-established and experienced installers fall into this trap? In this article, I will first delve into the technical issue and then offer my honest opinion on why we are suddenly observing many new sizing issues in 2025.

Manufacturers of photovoltaic components face fierce competition. They invest heavily in R&D to release the next model of solar modules or inverter with better efficiency and optimized costs. Every tenth of a percent gained is a new success! However, it is a shame to encounter solar plants made up of the best components but never reaching the expected performance due to a simple sizing error.