Many solar farms run with lower performance and higher operating costs because they are not monitored and optimized by their own monitoring. hep is taking a different approach here and has taken the monitoring of its solar farms in Germany, Japan and the USA into its own hands since 2017. The operations and monitoring team combines high-tech with extensive knowledge of the peculiarities of individual solar farms.
The interaction of modern remote monitoring with comprehensive experience and a personal perspective ensures high cost efficiency and system availability at hep. In addition, hep gains valuable knowledge that flows into the operation of existing plants and the development and construction of future projects. Investors in hep solar parks benefit from this over a long period of time. Susanne Mook, Senior Associate Operations and Monitoring at hep, reveals exactly how hep’s monitoring works and how it can be used to track down a snake in a transformer station on the other side of the world.
Ms. Mook, why aren’t so many solar parks making full use of their maximum performance potential?
Susanne Mook: “Solar parks often do not achieve their maximum output because they are not monitored at all or only poorly. Good monitoring needs two components: technical monitoring using modern sensors and personal experience with the peculiarities of individual solar parks. For example, it is important for us to know if and when the rice harvest takes place in the immediate vicinity of a solar park in Japan. Because this means an increased level of dust on our panels. In the event of a short-term reduction in performance during the harvest season, we can assume that no technical defect has caused the cause is. The same applies to the pollen count in spring in Germany or the USA. If I then also know that it rains a lot at a certain time of the year, I can assume that the pollution will be naturally washed away within the next few days. This is very sustainable and cost-effective at the same time. With the knowledge of the special features of individual solar parks, we can optimally interpret the technical data of our remote monitoring.”
How exactly does the remote monitoring of hep solar parks work?
“We have equipped our solar parks worldwide with various sensors and data loggers that we can use to see exactly when and where a defect occurs in a solar park and what the extent of it is. Among other things, this involves direct access to individual inverters and strings, but also to sensors for wind, temperature and solar radiation. The data is collected using a data logger and transferred to a software platform that we can access here at the hep headquarters and in our branches in Japan and the USA. Our on-site optical monitoring using cameras is also very important, with the help of which we can see whether the weather is bad and the power output is therefore temporarily falling.
So you personally check hundreds of sensor values from your solar parks in Germany, Japan and the USA every day?
“Yes, exactly, we check all our ‘babies’, as we call our systems, completely every day. In this way we can determine whether a module or a string is defective. You can only see this if you really go into detail, because individual defective modules or strings are not necessarily immediately noticeable in the overall picture of a large solar park. At some of our solar parks we check up to 200 individual inverters. If I don’t receive any data from an inverter, I can switch directly to it via our software and see whether it is not working itself or whether there is a data line problem. We are also able to read the insulation values of each individual string and thus recognize whether the insulation of a power line is damaged. Something very strange happened to us in Japan. There we determined the failure of a transformer station by monitoring, which is very unusual. We immediately dispatched a technician who quickly found the cause: a snake had entered through the ventilation and caused a short circuit. As a result, we installed tighter ventilation grilles in all of our solar parks in the country.”
In addition to personal monitoring, is there also a technical alarm system that draws attention to defects or unusual values?
“In addition to personal monitoring, hep has an automated alarm system that we can configure to the specifics of individual solar parks. If, for example, an inverter delivers no data or incorrect data for a certain period of time, we receive an alarm directly on our cell phones. In this way, we do not miss any unexpected fluctuations in the performance of our systems. What we then make of it is again a question of experience and knowledge of the local peculiarities. For example, if I know that a tree is shading part of our panel at a certain time of day, I can assume that a drop in performance in this sector is not a defect – this saves maintenance costs, because we don’t have to immediately send a technician on-site to do physical troubleshooting and repairs. The monitoring of solar parks in the interaction of know-how and online data analysis is therefore also an effective tool to increase cost efficiency.”
So hep not only uses remote monitoring to keep solar parks efficient, but also to minimize operating costs?
“I agree. Since we at hep operate our monitoring ourselves, we have the advantage that we know our parks like the back of our hand and can assess the situation on site with a good sense of proportion. In this way, we can flexibly decide whether we actually need a technician or whether it is a minor fault that can be remedied during the next scheduled maintenance. We are also able to personally brief maintenance employees before they are deployed and provide them with a detailed picture of the situation on site in advance. This not only saves time that would otherwise often have to be spent on tedious searches for defects, it also minimizes production downtime. This minimizes the costs of operating our solar parks and at the same time offers the security that downtimes can be reduced to a minimum. This is how we maximize the power at which our parks generate electricity. Another advantage for hep is that we collect valuable data and experience in monitoring, which we then incorporate into our holistic concept of development, construction and operation of solar parks. In this way, hep builds up important knowledge that can be used to make existing and new solar parks even more powerful and efficient.”
Sources: Innovations Report (IDEA TV), pv magazine, hep global