SunPeek wins 2026 STSHC Solar Award for advancing performance monitoring

The SunPeek Open-Source Project has won the 2026 Solar Award by the IEA Solar Technologies & Sustainable Heating and Cooling Programme (IEA STSHC). SunPeek is a software designed to verify whether large-scale solar thermal plants deliver the heat output they should. Maria Moser from the Austrian company SOLID (centre) and Philip Ohnewein, formerly Researcher at AEE INTEC (left), accepted the award on behalf of the SunPeek Steering Committee at EuroSun2026 in Freiburg mid-September. They were joined by Carina Seidnitzer-Gallien also from AEE INTEC (right). Photo: Bärbel Epp

“With SunPeek, we have recognised an innovative solution that helps ensure the longterm high performance of solar heat plants. The software is freely available and can be used with plants equipped with both non-concentrating and concentrating collectors”, said Daniel Mugnier, Chair of the Solar Award Committee in his laudatory speech. SunPeek was selected from five nominees from around the world. The shortlisted projects and products are presented here.

The Solar Award 2026 focused on innovations developed within the last five years that demonstrate sustainability, measurable market impact, and a technology readiness level (TRL) of at least 7.

“We are honoured to receive the 2026 IEA STSHC Solar Award, which we share with everyone who has contributed to SunPeek. Large solar thermal plants earn their money over decades, which gives automated, analysis-assisted operation a clear business case. The award recognizes SunPeek as a milestone on that path. Each plant is sold on a promise, usually a fixed annual yield. SunPeek follows ISO 24194 and checks the plant against what it should deliver under the actual weather and measured operating conditions, which is a far sharper and fairer test for all stakeholders,” said Philip Ohnewein, SunPeek’s Lead Developer and a member of its steering committee.

Special features of SunPeek open-source software Source: SunPeek

Open-source software for reliable performance verification

SunPeek has been publicly available as open-source software since 2023. It can be used in two ways: to verify performance during commissioning and to monitor performance during operation.

The performance assessment with SunPeek is very reliable, because it is based on the Power Check method, which is described in the ISO 24194 standard. This standard was developed by an international group of scientists and industry practitioners, drawing on experience gained from more than 100 Danish solar district heating plants. The Power Check compares a measured output with what a plant should deliver under the actual weather and operating conditions.

Deployed at more than 20 large-scale plants

“SunPeek is running at more than 20 large-scale plants in six countries, and five industry partners are evaluating or deploying the software,” said Philip Ohnewein during his presentation at the award ceremony. At the 5.7 MW solar district heating plant in Graz, Astria, SunPeek analyses helped optimise the collector cleaning schedule, which raised measured performance by 10 %.

How SunPeek works

Adding a new plant to SunPeek involves just a few steps before the Power Check can be carried out. First, users describe the installation and select the collector model from the SunPeek collector database or define a custom collector. Then they upload the monitoring data set, sampled intervals of five minutes or less. SunPeek supports all data in tabular format, including the widely used CSV format. The third step is sensor mapping. This involves assigning the sensor to the correct input slot for the calculation algorithms. Once the safety factor has been specified, the requirements for the ISO 24194 Power Check are met and the remaining calculations are performed automatically.

The IEA STSHC Programme has presented Solar Awards since 2003. Information on previous award winners is available on the official Solar Award website. The STSHC Programme – former Solar Heating & Cooling Programme – updated its name during the 50^th anniversary celebration at EuroSun2026. It brings together experts from around the world to advance solar thermal technologies and strengthen their role in sustainable energy systems.

Websites of organisations mentioned in this news article:
IEA STSHC Programme: https://www.iea-stshc.org/
STSHC Solar Award winner 2026: https://www.iea-stshc.org/article?NewsID=1613
SunPeek: http://www.sunpeek.org
SunPeek live demo: http://www.demo.sunpeek.org
SunPeek source code: http://www.gitlab.com/sunpeek
EuroSun2026: https://www.eurosunconference.org/