CSP Services has been selected, together with the German institution DLR, winners of the 2021 SolarPACES Award in the category of Technology Innovation for their solar flux measurement system. Today we have the opportunity to interview Steffen Ulmer, Co-Founder and Managing Director of CSP Services, to further understand this achievement into our industry and his views on the future of the technology.

Dear Steffen, first, thank you very much for attending us today. We want to congratulate the entire CSP Services team for this year´s SolarPACES Award. Could you please explain a little bit more how your flux measurement system works?

Thank you very much. Before answering your question, I would like to thank the SolarPACES committee for this important recognition. Actually, it is already our fourth SolarPACES award after 2009, 2014 and 2018.

As a spin-off of the German Aerospace Center (DLR) we have a strong scientific background and are keen to stay at the cutting edge of technology. We see ourselves as a link between academic research and industry, with a clear focus on what the market needs and what our clients actually demand. Therefore, we understand this award as a further proof for our successful R&D activities and technology transfers over the past two decades.

The first tests and initial developments of this flux measurement method actually started in an R&D project that I led more than 15 years ago. Back then I was still working with DLR at the Plataforma Solar de Almería (PSA). After my change to CSP Services the colleagues at DLR further improved this promising methodology. Now, we are working on a commercial version and full-scale demonstration of the system in a joint project with DLR.

The resulting product is a new measurement system that determines the solar flux density distribution on the receiver of a solar tower in real time. The intensity of the concentrated solar irradiance hitting the receiver and its spatial distribution is a valuable information for the plant operator. It allows the alignment of the heliostats in the best possible way and thus boosts the efficiency of the power plant and at the same time increases the receiver lifetime. It can also be used to separately determine the efficiency of the receiver and the solar field, which otherwise can only be determined as a whole. So far there has been no workable system for commercial power plants. The hardware setup of our system is fairly simple, employing only digital cameras and a computer to calculate the flux density on the basis of image data. As a basis for correct calculations, the reflective properties of the receiver are determined once with a specially developed scanning technique when setting up the system. This scan is performed at night to not disturb operation and can be repeated for example once a year to consider degradations of the receiver surface.

We understand the flux measurement is not the only part of the services your company offers to the sector. Which other services are provided by CSP Services that could improve the existing O&M of the Spanish CSP fleet?

That’s correct, we offer quite a few services for O&M of existing plants. I can give you three examples:
Firstly, our QScan drone measurement system is able to quickly scan the thermal and optical performance of a parabolic trough solar field. This enables the operator to identify issues like damaged receiver tubes and its root causes, collector misalignments and tracking offsets, or broken mirrors. The information can be directly used to improve the solar field performance.

Secondly, within our department for fluid and component services we especially address the hydrogen problem in parabolic trough plants. This includes HTF analysis, getter saturation measurement, modelling, specific hardwarehardware, and the elaboration of mitigation strategies.

Finally, our Q4cast nowcasting system reliably predicts local cloud movements and provides a spatially-resolvedspatially resolved forecast of the solar irradiance in the solar field. This can be used to improve plant control and to reduce thermal stresses, thus increasing plant performance and lifetime completely independent of the skill of the operator.

Our specific and often highly customized services are complemented by expert consulting services, which can have a more holistic approach, but can also investigate specific problems in detail.

You are a member of a technical company, very close to R&D and the latest developments into the sector. What are your views on the future auctions that will happen in Spain? Do you foresee any changes to the design and operation of the new CSP compared to the ones that have been in operation for more than a decade?

I definitely expect to see larger plant sizes as the previously limited 50MWel, as this reduces the relative costs considerably. I guess we will also see a higher share of central receiver systems than before, most likely with molten salt receivers. They have the potential of significant cost reductions, especially if we accomplish building more standardized systems with more automated operation and maintenance. That’s the reason for our ongoing work on standardization and other O&M topics in several German R&D projects.

Storage will be the most important asset of future CSP plants, so its size, its integration in the plant and the interaction with the grid will most likely change to a more demand-side orientation and management. CSP plants should be used as fully dispatchable power plants that charge their thermal storage during day-timedaytime, when PV is generating cheaper electricity, and produce power when it’s really needed: in the evening, in the early morning and during peak demands.

Depending on the rules of the auctions, I guess we will also see certain integration of PV, at least to cover the internal consumption of the plant during daytime. Technology-wise I hope that we will see some changes in the used heat transfer fluids (silicone oil and molten salt instead of BP/DPO), higher operating temperatures, new and cost-optimized heliostats, and generally a higher automation and digitalization of operation and maintenance.

Finally, how would you assess the impact of the Spanish CSP auctions into the worldwide market? Do you think these auctions could be a trigger to see more installed capacity in the world?

It is a very important signal. A continuous pipeline of projects is of utmost importance to keep the CSP industry healthy and to realize the required improvements for further cost reductions. Spain is world leader in installed CSP capacity and Spanish companies are leading in knowhow and experience in this technology. With these auctions Spain strengthens its position and its industry. One big advantage of the CSP technology is that a high share of value creation can be realized in the country where the plants are built. Already the first phase of CSP deployment in Spain illustrated the fact that the invested public funds were more than paid off by the private money it leveraged, the jobs that were created and the taxes acquired.

In the future, with growing shares of electricity from renewable energies, energy storage and grid stabilisation inevitably will become more and more important. Green hydrogen is a big topic and CSP perfectly fits in the need for 24h electricity production that is required to efficiently operate the electrolysers. Spain has by far the largest potential for solar power of all European countries – in solar resource as well as in suitable and available land area. Pursuing this way Spain can become the most important provider of solar energy for Europe. Similar things will happen in countries with the best solar resources worldwide like Chile, Namibia or Australia.

Compared to PV or wind, CSP is still relatively at the beginning of its learning curve. At first sight this might look like a disadvantage in a race that has already started. But on the other hand, this means that the potential for improvements, standardization, mass production and related cost reductions is still very high. However, this requires constant investments, political support and a certain market volume. The integration of CSP in hybrid concepts and its use for green hydrogen production will also play a role. As you can see, the possible contributions of CSP to the energy transition and its chance to grow worldwide are huge. We at CSP Services, and surely the entire CSP community, will do our best to make it a success.

Thank you very much for your time.