By ESCI – European Science Communication Institute gGmbH

Most buildings in Romania are decades old and the energy used to heat them is increasingly expensive. Can researchers help cut costs and reduce greenhouse gas emissions?

As Romania braces itself for a long winter with skyrocketing gas prices, renewable energy seems to be one of the only viable options for heating homes and public buildings. A project at the University Politehnica of Bucharest (UPB) shows how solar and thermal energy technologies could be used together to reduce costs and greenhouse gas emissions.

Researchers have upgraded the heating system of a building belonging to the Faculty of Power Engineering called the Renewable Energy Sources Lab. The Lab was previously connected to Politehnica’s gas-fired heating network, but it has never been adequately heated during the winter because it is located at the end of a network’s branch.

Now the team of researchers led by vice-dean Dr. Constantin Ionescu has demonstrated that a hybrid heating system powered by geothermal and solar energy could improve the thermal comfort of the student. The solution, which includes photovoltaic panels, solar thermal panels, and geothermal heat pumps, can be easily replicated elsewhere.

The Bucharest site is part of the WEDistrict project, and the European Union funds it through the Horizon 2020 programme. In addition to Bucharest, renewable district heating solutions are being implemented in three other locations: Alcalá de Henares (Spain), Luleå (Sweden), and Bierutów (Poland). 

“WEDistrict was born from our desire to show that fossil fuels can be replaced by optimally integrating different renewable energy sources in both existing district heating systems and new ones,” Dr. Ionescu says.

In Romania buildings account for approximately 30% of the total energy consumption, according to Eurostat. Many public buildings, houses and blocks of flats were erected before the fall of communism and little has been done to upgrade them and make them energy efficient. 

If replicated, projects like WEDistrict could help the European Union reach its goals of becoming the first carbon-neutral community by 2050 and cutting net greenhouse gas emissions by 55% by 2030, compared to 1990.

How it works

The Renewable Energy Sources Lab has a total surface of 400 square metres. Researchers say it was the perfect site to test how renewable energy sources could be integrated into an existing district heating and cooling network.

The project has several components. First, photovoltaic panels are installed on the roof to capture the sun’s energy and convert it into electricity. This electricity is used to power the geothermal heat pump that heats the building. The pump then transfers heat from the ground to the building using a network of water-filled underground pipes, which absorb the earth’s heat and transfer it to the Lab.

By using this geothermal system in tandem with photovoltaic panels, researchers can heat the lab only relying on renewable energy.

The researchers wanted their solution to be easily replicated by anyone, for example those living in a block of flats in one of Bucharest’s districts. It’s why they’ve chosen several different products for each technology they’ve incorporated.

“For instance, we’ve used three types of solar panels, three types of inverters,” says associate professor, Dr. Mihai Vasile Sănduleac. “We wanted to build a solution that can be integrated, that simulates real-world conditions.”

The whole project is monitored and controlled through a SCADA-EMS system, a software application for industrial processes that enables the researchers to know all the necessary parameters in real-time. This system can make decisions automatically, and it also helps researchers to gather a lot of data for future analysis. The tool is available for free to anyone who would like to use it or and modify it.

“The SCADA application is open source and cross-platform—it can run on Microsoft Windows, Linux, and macOS,” adds Dr. Sănduleac.

With most of the work done, the researchers think about the next step. “If we can replicate the project to three or four buildings within the campus, then we will be producing more green energy,” says professor Dr. Roxana Pătrașcu. 

She and her colleagues hope that their solution will gradually be adopted by the public sector, as well as by people living in buildings located at the end of a heating network’s branch.

“The project can easily be replicated in residential areas,” says Dr. Cosmin Mărculescu. “We’ve proven that such a project can be successfully used in locations with complex operating requirements.”

Making buildings energy efficient

So far, Romania has been slow at retrofitting its buildings to make them efficient. More than 90% of the country’s public buildings, houses and blocks of flats were built before 1989, when energy performance wasn’t taken seriously. According to a report by independent energy think tank EPG, one in seven families in the country faces severe housing problems such as poor quality walls, floors, and window frames.

“To achieve the energy efficiency goals and targets established by national and EU strategy documents, the Romanian building stock needs an increased energy performance,” the EPG report reads.

Aiming for energy efficiency is one thing; achieving it is another. Although different European mechanisms support the improvement of building efficiency, progress has so far remained slow. Typically each year only about one to three percent of Romania’s residential buildings are made more efficient through simple processes that could reduce energy consumption by up to 60%. More complex projects aiming to pass the 60% efficiency mark are almost nonexistent.

With this new hybrid heating system, the researchers at the University Politehnica of Bucharest hope to inspire others to bet on green energy. The solar panels and the heat pump they’ve installed could potentially reduce the university’s CO₂ emissions by around 32 metric tonnes per year.