Interview with Roxana Pătrașcu on the future of centralized district heating systems


Prof Roxana Pătrașcu of the Faculty of Energy Engineering at the University Politehnica of Bucharest is in charge of the implementation of the solar geothermal system at the WEDISTRICT demosite in Bucharest. She tells ESCI about the obstacles faced during the installation of the systems and the impact of the COVID-19 pandemic.


ESCI: What are the main advantages of implementing a geothermal solar hybrid system within an existing centralized power supply system, like the one at University Politehnica of Bucharest?
Roxana Pătrașcu: Implementing a geothermal solar hybrid system in a university campus is a novelty in Romania. The project demonstrates that a solution based on the production of energy from renewable resources can be integrated into a classic existing system. There are many advantages to this. From an energy perspective, the new system has reduced natural gas and electricity consumption, resulting in significant financial savings for the university. Moreover, by transitioning away from fossil fuels, we have reduced carbon dioxide emissions, positively impacting the environment. Importantly, the system provides a comfortable and sustainable environment that aligns with European standards for everyone on campus.


ESCI: What were the main challenges in developing the hybrid system, and how did you overcome them?
Roxana Pătrașcu: We encountered various technical, administrative, economic, and contractual challenges during the implementation of the hybrid system. However, through the dedicated efforts of our team, we managed to overcome them.
Interconnecting the new system with the existing infrastructure presented technical challenges, particularly in the thermal point facilities. To overcome these challenges, we kept in constant contact with the university’s technical team, the geothermal hot spot, and the installed facilities existing in the hot spot, addressing each challenge step by step. We ensured that the thermal point connection met the latest standards, allowing the interconnected system to function effectively.
Another challenge arose during the installation of the hybrid system components. We had to optimize the system’s software for integrated operation. This was fixed through ongoing evaluations, discussions, and collaboration with external partners, taking into account that, practically, our achievements are quantified by the impact indicators that are monitored within the consortium.


ESCI: The COVID-19 pandemic started just a few months after the project’s initiation. How did it impact its development?

Roxana Pătrașcu: The unforeseen COVID-19 caused some disruptions in our project. However, we remained united and adapted to virtual communication platforms such as Microsoft Teams. This allowed us to progress with certain stages of the project. We had also planned for economic fluctuations and allocated a sufficient budget to accommodate any price variations for equipment and materials. This helped us overcome some of the financial challenges brought by the pandemic.


ESCI: Are the end users of the demonstrator – teachers, staff, researchers, and students- already benefiting from the new system?
Roxana Pătrașcu: Absolutely. The system is fully functional and has significantly improved thermal comfort within the building. In fact, the solar power system has generated more energy than estimated, and on particularly hot days,where the outside temperature reached 36/37°C , the system transitions to passive cooling, eliminating the need for additional energy consumption. Throughout the winter and summer, our colleagues and students have enjoyed enhanced comfort both in terms of heating and cooling. We can now conduct laboratory activities for disciplines such as the use of thermal energy or heat supply and offer new research opportunities, including the development of doctoral theses focused on expanding hybrid centralized power systems. Looking ahead, we have the potential to connect additional alternative energy sources to the existing system. This serves as a solid foundation for generating innovative ideas and addressing future challenges in sustainable energy for the next generations.

Photovoltaic panels installed at the Bucharest demosite to power the heat pumps for the district heating system

ESCI: Can the demonstrator be replicated by other companies in other cities?
Roxana Pătrașcu: Certainly. The demonstrator serves as a model of flexibility, replicability, and scalability. Our pilot project can be replicated not only within other areas of our university campus but also across different university campuses or residential areas lacking efficient centralized heat supply systems. Private companies and technology developers may find our project to be an excellent reference for best practices and an opportunity to enhance existing technologies and identify new functionalities. The WEDISTRICT project can serve as a guide for further development at various levels, including municipalities, the private sector, and the education sector, especially in regions with inadequate heating or centralized power networks.


ESCI: What would be the essential key factors to achieve this?
Roxana Pătrașcu: The key factors lie in the interest of decision-makers to leverage financial support and identify the best funding options, such as grants or private investments, for implementing such solutions. Additionally, a stable legislative framework is crucial to facilitate interconnection with existing systems. In our demosite, the thermal interconnection was straightforward as the power network belongs to the university rather than the public grid. However, in other cases, obtaining approvals and permits for electrical interconnections may pose challenges.


ESCI: What is your vision for a sustainable future in district heating?
Roxana Pătrașcu: I believe that the future of district heating in Europe and beyond lies in solutions that prioritize energy efficiency and flexibility.
Existing centralized power solutions are necessary due to factors like urban concentrations, population growth, and the increasing demand for comfort. To meet these demands, we must develop fourth-generation centralized power systems that reduce reliance on fossil fuels and prioritize sustainability.


ESCI: How can integrating energy production alternatives into existing systems contribute to this?
Roxana Pătrașcu: Integrating renewable energy alternatives into existing systems, as demonstrated by our project, is crucial. Whether it’s utilizing renewable sources or converting waste heat from industries, these approaches offer resource efficiency and contribute to reducing polluting emissions.
Apart from the implementation of these alternatives in existing systems, another solution is injection from sources such as cogeneration plants, which are also clean solutions. These two solutions, the insertion of these alternative sources and the use of cogeneration, support the development of centralized power both in the European Union and worldwide.

Read more about the thermal subsystem in our demosite brochure.


ESCI: Thank you for this interview!

WEDISTRICT’s Bucharest demosite, led by the University Politehnica of Bucharest, in Romania, aims to integrate renewable energy sources into the existing district heating and cooling network. This has been achieved with a hybrid geothermal and solar energy system, using heat pumps powered by photovoltaic panels. Watch our video to learn more about the demosite.