Page 59 - European Energy Innovation - winter 2017 publication

Winter 2017 European Energy Innovation 59

COMMUNICATION

The SOTHERCO project:
a step further towards
autonomous solar buildings

By Marc Frère (University of Mons – Belgium), Gilbert Descy (BE-SOL – Belgium)

During the last decade, Solar Thermal Systems suffered from
a lack a public support while such systems are mature for
domestic hot water production and could be used for solar
cooling. Could Solar Thermal Systems know a new golden
age when applied to space heating ?

Such a question is challenging as in the major part of SOTHERCO test bench for seasonal heat storage technologies
Europe, the efficient harvesting of solar energy and its
conversion into heat takes place during summertime densities around 150 to 190 kWh/m3 (an order of magnitude
while heat demand for space heating occurs mainly in higher compared to seasonal heat storage in the ground)
wintertime. There is thus a need for technologies able to and specific thermal powers of around 100-150 W/kg of
store large quantities of thermal energy during summer (a reactive solid material were reached. Considering the best
few thousands of kWh per dwelling in Northern and Central combinations, it was found that the complete covering of
Europe) in a reduced volume and without losses so that this the heat demand (space heating) of a building using solar
energy could be efficiently recovered during winter. energy is possible provided very low energy (passive)
houses are concerned with a restriction for very cold
The SOTHERCO1 project consortium, granted by EU within climates. The question whether such a target (solar coverage
the FP7 framework, worked on that question and is now corresponding to 100% of the heat demand) makes sense
delivering its results and conclusions2 3 4 after more than economically is still pending. However, technically, real
4 years of R&D activities. The consortium worked on the demonstration case studies could be developed in the next
concept of thermochemical storage (heat storage using a years. Application to less performant buildings needs further
reversible chemical reaction) and tried to bring technology developments and must be probably considered with a
solutions up to a TRL equal to 5-6 in order to lay the reduced solar coverage ratio of the need. ●
foundations of future demonstration projects. Solutions had
to be brought (i) at the reactive solid level (cost effective, Contact details:
long-term stability, high energy density), (ii) at the reactor info@be-sol.eu
level (simple conception, compactness, enhanced heat marc.frere@umons.ac.be
and mass transfer to reduce the gap between the energy http://sotherco.eu/
density at the reactive solid material and at the reactor
levels and (iii) at the system configuration level (efficient
connection of all the components). Six new reactive solid
materials were synthesized, four reactor technologies
were investigated and two system configurations were
proposed. Best in kind solutions (one material, two reactor
technologies and the two system configurations) were
tested in relevant environment at a scale of a few hundreds
of Watts (in between lab scale and real scale). Energy

1) SOTHERCO Consortium: BE-SOL (BE), UMONS (BE), ULiège (BE), ULB (BE), CEA (FR), UVSQ (FR), AIT (AT)
2) Skrylnyk O., Courbon E., Heymans N., Frère M., Bougard J., Descy G., “Energy Performances of an Open Sorption Reactor with Ultra-Low Grade Heat Upgrading
for Thermochemical Energy Storage Applications”, Energy Procedia, 137, 304-316
3) Courbon E., D'Ans P., Permyakova A., Skrylnyk O., Steunou N., Degrez M., Frère M., "Further improvement of the synthesis of silica gel and CaCl2 composites:
Enhancement of energy storage density and stability over cycles for solar heat storage coupled with space heating applications" in Solar Energy, 157, 532-541,
https://doi.org/10.1016/j.solener.2017.08.034 (2017)
4) Permyakova A., Skrylnyk Oleksandr, Courbon Emilie, Affram M., Wang Sujin, Lee U.-H., Valekar A.H., Nouar Farid, Mouchaham G., Devic Thomas, De Weireld
Guy, Chang J.-S., Steunou Nathalie, Frère Marc, Serre Christian, "Synthesis optimization, shaping and heat reallocation evaluation of the hydrophilic Metal Organic
Framework MIL- 160 Al" in ChemSusChem, 10, 7, 1419–1426, 10.1002/cssc.201700164 (2017)

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