Posted: October 1, 2026
Figure 1 left to right, Luico Mesquita - STSHC Chair, Maria Moser - SOLID, Philip Ohnewein - Carina Seidnitzer-Gallien - AEE Intec
Freiburg, Germany, September 2026 - The SunPeek Open-Source Project has won the 2026 Solar Award of the International Energy Agency Solar Technologies & Sustainable Heating and Cooling Technology Collaboration Programme (IEA STSHC). SunPeek is software that checks whether large solar thermal plants deliver the heat they should.
The SunPeek Open-Source Project exemplifies outstanding innovation in solar heating and cooling that stimulates or create markets by improving technical or non-technical features. Maria Moser and Philip Ohnewein accepted the award on behalf of the SunPeek Steering Committee at EuroSun 2026, the International Conference on Sustainable and Solar Energy for Buildings and Industry of the IEA SHC and ISES.
Figure 2 SunPeek Open-Source Software
“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. Anyone can use it free of charge, including commercially," said Philip Ohnewein, lead developer of SunPeek and Steering Committee member.
The Solar Award focused on innovations developed within the last five years that demonstrate sustainability, measurable market impact, and a minimum technology readiness level of TRL 7. Additional consideration was given to startup companies less than 10 years old.
Project Impact
SunPeek, publicly available since 2023, is the reference implementation of ISO 24194, the international standard for checking the performance of solar collector fields. It compares measured output with what a plant should deliver under the actual weather and operating conditions,
helping plant owners and operators verify performance guarantees at commissioning and to monitor plants throughout operation.
SunPeek runs on more than 20 large-scale plants in six countries, and five industry partners are evaluating or deploying it. At the 5.7 MW Fernheizwerk Graz plant, SunPeek analysis helped optimize the collector cleaning schedule, which raised measured performance by 10%.
For a representative 2,000 m² plant (about 1,000 MWh/a), the estimated benefits are 5% more solar yield, about 6% more CO2 avoided, €2,000 a year lower O&M costs and a 6–7% lower levelized cost of heat.
About SunPeek
SunPeek is open-source software for performance checks and monitoring of large solar thermal plants, licensed under GNU LGPL and BSD-3-Clause. The project publishes its work openly: peer-reviewed papers, including one in the Journal of Open Source Software (2026), four open monitoring datasets from operating plants, and contributions to the IEA SHC Task 68 Guide to the ISO 24194 Power Check. All of them are collected at zenodo.org/communities/sunpeek.
www.sunpeek.org · Live demo: www.demo.sunpeek.org · Source code: www.gitlab.com/sunpeek
About IEA STSHC
The IEA Solar Technologies & Sustainable Heating and Cooling Technology Collaboration Programme works to increase the deployment of solar heating and cooling technologies through international collaboration, research, knowledge sharing, and market support. IEA STSHC brings together experts from around the world to advance solar thermal technologies and support their role in sustainable energy systems.
www.iea-stshc.org
Media Contact: Ben Stinson, STSHC Secretariat, secretariat@iea-shc.org