Store sunlight at the highest temperature

Storing the sun’s energy at temperatures above 1,200 degrees Celsius is the goal of the new European project SUNSON (“Son of the Sun”). This milestone would mean more than double the operating temperature of currently existing solar thermal power plants.

In this way, the project, coordinated by the Polytechnic University of Madrid (UPM) in Spain, aims to promote a new generation of more compact and efficient solar thermal power plants that make the energy sector more flexible. To meet this challenge, the proposed solution combines solar concentrators with advanced optics, phase change materials for thermal storage, and thermophotovoltaic converters for electricity generation in a single system.

The project, financed by the European Agency for Climate Infrastructure and Environment (CINEA), has a multidisciplinary consortium led by the Polytechnic University of Madrid (UPM), made up of 6 European organizations that includes companies (IONVAC Process and HOLOSS), centers technological centers (IDENER), public centers (CIEMAT) and universities (the Norwegian institution NTNU, together with the UPM). The areas of specialization cover a wide range of disciplines focused on the solar energy and sustainability sector.

“The SUNSON project will try to solve one of the biggest energy challenges we are facing this century: the uninterrupted supply of renewable energy,” explains Alejandro Datas, project coordinator and professor and researcher at the Solar Energy Institute (IES) of the upm. “If successful, the technology developed at SUNSON aims to promote a new generation of more compact and efficient solar thermal systems that can produce power whenever it is needed, regardless of whether it is sunny or not.”

the sun in a box

SUNSON proposes a clear advance in the field of renewable energies, especially solar energy, where the great limitation is the lack of economic and efficient solutions when demand is intermittent. Specifically, the objective of SUNSON is to demonstrate the feasibility and potential of a solution that integrates energy conversion and storage in a single highly modular and compact device (SUNSON-BOX).

The system is based on conversion technology that harnesses solar energy to produce heat, store it, and generate electricity on demand. This decoupling avoids dependence on variability in direct supply from renewable sources, thus considerably increasing its energy integration flexibility. This will make it possible to generate electricity according to demand and, in turn, the excess heat can be used in industrial heat processes, domestic hot water or heating. For this reason, its application is very promising in the energy, industrial, and building sectors, and even for the future generation of hydrogen. In order to facilitate its design, feasibility and replicability, the project will also develop a powerful computing tool (SUNSON-TOOL) that integrates artificial intelligence algorithms.

In the next almost 4 years of the project, the SUNSON team intends to develop a prototype that is 10 times more compact than conventional solar thermal systems thanks to the incorporation of phase change materials that store energy in the form of heat at temperatures above 1,200 degrees. centigrade At these temperatures, the heat becomes incandescent. For this reason, the system incorporates thermophotovoltaic converters that directly transform incandescence into electricity. The technology will be validated at the Plataforma Solar de Almería (PSA) of CIEMAT, a leading center in research in solar thermal technology, which will facilitate the future stage of development and commercialization.

Storing the Sun’s energy at temperatures above 1,200 degrees Celsius is the goal of the new European project SUNSON. In the image, a symbolic artistic recreation of the concept. (Illustration: Amazings/NCYT)

Award winning energy storage

Through funding obtained from the European Union, which began within the framework of the European Amadeus project approximately six years ago, the group of researchers led by Alejandro Datas managed to develop a first energy storage prototype on a laboratory scale.

“Recently they have financed us two more projects, the Thermobat and the SunSon, with which we are going to use the technology in two specific applications: the storage of electricity and the direct storage of concentrated solar energy. With this financing we are going to develop two pre-industrial prototypes with a greater accumulation capacity, a key intermediate step to be able to reach an industrial phase and be able to put the technology on the market”, explains Datas.

Specifically, the technology on which the Thermobat and SUNSON projects are based was considered the best European invention at the Radar Innovation Awards, awarded in November 2022 by the European Commission, within the Kickstarter category. These awards recognize the most promising innovations in Europe created from EU-funded research and innovation projects. (Source: UPM)