The PoliGrid project – the Politecnico di Milano's smart grid – was set up to ensure greater continuity of electricity services to the campus of Piazza Leonardo Da Vinci, Via Bassini, Via Bonardi and Via Golgi. The extended Leonardo-Bassini-Bonardi-Golgi campus is now a real multi-vector energy district, able to provide, among other things, highly flexible services to the public energy grid. 

An internal electricity distribution network at medium voltage (23 kV) is able to meet a need for about 15 GWh each year, with energy peaks of 4 MW in the summer. A dozen photovoltaic systems on various buildings are connected to the grid, with a total power output of just over 1 MW. Then a 2-MW cogenerator produces both electricity, about 90% of which is for local self-consumption, and thermal energy, powering a district heating network that extends for over 2 km within the campus. The combination of high-efficiency cogeneration and photovoltaic production achieves a level of self-production that enables internal energy needs to be met with minimal climate-changing emissions.

Since 2015, the Politecnico has invested considerable resources into modernising the energy network of its site at Città Studi, in order to make it more efficient. The first stage involved the modernisation of the district heating network, and the installation of a CHP engine able to guarantee over 82% efficiency. The cogenerator  provides 12 GWh of electricity to the campus every year, ensuring a stable, low-emission and cost-effective supply. Eleven photovoltaic systems have been installed more recently, with a total power output of just over 1,000 kW. This initiative forms part of the Strategic Sustainability Plan put forward by the University in 2022. Another 3 installations are coming into service in 2024 and will be connected up to the PoliGrid, bringing the total capacity of these systems close to 1.5 MW.

The technology centre, the home of the PoliGrid, is located at the intersection of Via Golgi and Via Pascal and extends over two floors. The basement houses all the heat exchangers, pumps and pipes that power the district heating and cooling networks.  The heat generators are all on the ground floor; a single room houses two industrial boilers (6+6 MW) that record an average output of over 97% a year, and an absorption refrigeration unit that converts the thermal energy from the cogenerator into about 1.4 MW of cooling power.

A separate room accommodates the container that houses the CHP engine. The Jenbacher JMS 612 engine is able to recover 530 kW of energy from the initial intercooling stage, 50 kW from lubricating oil, 350 kW from cooling water and 850 kW from flue gases. With a displacement of 84,000 litres and 12 cylinders arranged in the form of a V, it operates with a 4-stroke engine cycle powered by natural gas. The cogeneration engine provides flexibility, safety and efficiency, ensuring that the flow of energy from the PoliGrid is managed in the optimum way.

A fibre optic network throughout the campus enables both production and consumption systems to be actively managed, providing the opportunity to develop, test and implement sophisticated algorithms for the improvement and management of complex energy networks in a real environment. Options such as the ability to calibrate the exchange of active and reactive power with the public network, the possibility of managing intentional controlled islanding, and of re-supplying and re-synchronising with the national grid, are all crucial aspects in relation to achieving European and national decarbonisation goals. All the systems in the internal energy network can be monitored and controlled both manually and automatically from the PoliGrid control room on the ground floor of the technology centre. In addition, since 2023, the PoliGrid has been equipped with a Central System Controller, a device envisaged by the CEI 0-16 Standard. This allows the implementation of highly flexible operations, opening the door to many opportunities in relation to demand/response and to local and global dispatching services.  This makes PoliGrid one of the most advanced testbeds for trialling innovative systems of control, which will enable the reception of large quotas of non-programmable renewables, while also maintaining high security, economy and efficiency in the management of the national energy system.

PoliGrid is a real, live, operational network. But it is also an experimental teaching and research laboratory, which hosts both students and businesses. The lab receives many requests for visits, mainly for educational purposes, and these take place every year during May and December. The university setting is also conducive for building good relationships with companies interested in testing their software products for the management of complex energy networks.

If you are interested, please contact us!

Project manager PoliGrid
Filippo Bovera
filippo.bovera@polimi.it