Renewable energy and green technologies are not totally new. But how to use them together so that it is an economical and therefore attractive solution? The international RESHeat project, in which experts from the SPIL laboratory at the Faculty of Mechanical Engineering also participate, want to answer this question. There are also plans for two demonstration installations on public building complexes which face different climate conditions, in Palombara Sabina, Lazio, a commune in the Metropolitan City of Rome, Italy, and Krakow, the historical capital Poland. These are the final development steps before the system is launched.

Heating and air conditioning consume more than half of the civic sector annual energy consumption. In EU households, heating and hot water alone, account for 79% of total final energy consumption. What's worse, three-quarters of heating and cooling requirements are still powered by fossil fuel energy. Nevertheless, the transition to renewables is still not smooth, often because it discourages high initial investments and operating cost.

„Not that existing technologies are not technologically good. The problem with current renewable energy sources, however, is that in most cases, they have to be subsidised. The goal of the RESHeat project is to develop the technology so that it is economically advantageous. If we succeed, renewables will be green. That is why we are preparing two demonstration installations in different climatic conditions, where those interested could come and see them and learn everything about how the system works," explains Professor Jiří Klemeš, head of the SPIL laboratory at the Faculty of Mechanical Engineering, Brno University of Technology. The project focuses on residential units, so demonstration installations will be on residential buildings in Rome, where it is relatively warm, and in Krakow, which is to the north of us and considerably cooler. Experts will be able to compare the effectiveness of both systems in different latitudes.

It is the team of the Laboratory of Process Integration for Sustainability, abbreviated to SPIL, that, as the name suggests, is in charge of integrating all technologies so that they become a functional and efficient system. "In general, a lot of energy can be saved, and emissions avoided, but again it consumes some funding for operating cost. For example, almost all heat pumps run on electricity, which means that we save something but consume something again. We will run the research to integrate renewable sources so that the pump also takes energy from solar collectors," explains Prof Klemeš. For solar collectors, they plan to use more efficient, so-called, smart units, which spin like sunflowers behind the sun to get the maximum energy input. This is very important, especially during the winter period, when the energy is much needed.

Civic Sector still has reserves in energy efficiency and related emissions

Researchers also want to solve another problem, and that is the fluctuating performance of renewables. "Fluctuations occur both in regular day-night cycles and with changes in weather or season. To make a real breakthrough in the use of renewables, we need to address energy storage. In our project, we want to use advanced underground energy storage. If you have soil with suitable properties, as, e.g. clay, heat can also be stored in the ground. It's relatively cheap and safe, so also promising," says Jiří Klemeš.

This time, the target group of the project is not industry alone, but cities, regions and other public entities as well. "It's promising because industry has been dealing with energy savings for some time. Even advanced industrial plants can still save some energy, but it's not tens of percent. On the contrary, the area of civic amenities still has higher reserves, and further research is also needed here," stated Jiri Klemeš.

The EU RESHeat project is planned for four years, ending in November 2024. In the first three years, researchers plan to work on process integration and gradually install and test parts of the system in sample residential units so that the last year of the project runs and data can be collected and the effectiveness of the solution verified. The project involves research institutions, cities and companies, that plan to subsequently introduce the technology or its components to the market. "These companies had to contribute 30% towards the development of the project, which is already a good example of the fact that they believe it will be useful. And of course, we believe that too. Energy savings will only work if it really spreads en masse” concludes Jiří Klemeš.

An important part of the RESHeat project is the demonstration and dissemination, where SPIL, FME, VUT has a remarkable record in smart media dissemination and organising worldwide conferences, e.g. as SPIL’20 attended by 443 participants from 49 countries and coming hybrid (both face2face and online) conference PRES’21 (31/10 – 3/11 2021, Brno, Czech Republic), where already more than 1,650 authors from 59 countries submitted their research works.

This project is supported by European Union’s Horizon 2020 research and innovation programme under grant agreement No 956255, project RESHeat (Renewable Energy System for Residential Building Heating and Electricity Production).

Project SPIL is funded by Czech Republic Operational Programme Research and Development, Education, Priority 1: Strengthening capacity for quality research Czech Ministry of Education, Youth and Sport (CZ.02.1.01/0.0/0.0/15_ 003/0000456).