Solar energy research center INES's new CALORIE testing platform (Liten, a CEA Tech institute) is a micro heating and cooling network. It was recently connected to a semi-virtual thermal test bench that replicates consumer behavior via a unidirectional substation tested under the EU THERMOSS project. Ultimately, the tests will contribute to a bidirectional substation that can be used to feed surplus solar thermal energy back into urban heating and cooling networks from any point, much as solar PV energy can be fed to the electricity grid.

A substation is where heat is delivered to users. Here, the consumer, emulated by the semi-virtual test bench, is a building whose annual behavior patterns are simulated in real time over twelve days (representative of each month) using thermo-hydraulic modules and TRNSYS software. Other users, this time real (INES buildings), were also connected to the system to test the substation's technical performance so that it can later be installed at other sites.

In addition to the tests that were completed, the project also gave the researchers involved valuable experience with substation technology and an opportunity to validate numerical models that could be used to develop a bidirectional substation—the first step toward a prototype that will be developed by Liten and set up at the CALORIE platform in 2019.