University of Palermo – Palermo (Italy)


A Rank® HT1 unit has been installed on the Campus of the University of Palermo, Italy. The machine is integrated into the trigeneration installation developed in the framework of the European project STS-Med (Small scale Thermal Solar units for Mediterranean communities).

The project

The Arca Consortium has relied on Rank® for a trigeneration system located on the Campus of the University of Palermo (Sicily, Italy). It was developed for the Italian pilot plant of the STS-Med European project. They also included a concentrated solar power (CSP) plant, biomass boiler, thermal energy storage (TES) tank, and absorption chiller.

The STS-Med project (Small scale thermal solar units for Mediterranean communities) focuses on developing, implementing, and disseminating cutting-edge technologies to improve the energy efficiency of public buildings and has four demonstration plants. STS-Med comprises 14 organizations from 6 countries (Italy, France, Cyprus, Egypt, Greece, and Jordan).

Technological innovation

The most important innovation lies in using a CSP system in small plants, providing electricity, hot water, and air conditioning to 20,000 users of public buildings in the Mediterranean area. The pilot system shows a valid combination of technologies capable of covering the total demand of towns and urban districts.

The installation consists of 21 fresnel linear concentrators modules with a surface of 470 square meters. It produces a maximum power of 220 kW and annual thermal energy above 310 MWh. The high-performance thermal energy storage tank provides energy without depending on effective solar radiation. It is composed of an 8 m3 molten salt tank with a thermal capacity of 400 kWh that operates between 160 and 260 °C. The Rank® ORC unit produces 10 kW electricity with a net electrical efficiency of 10%A 23 kW. A LiBr absorption chiller (COP of 1.1) integrated into the HVAC system of the ARCA offices share a common cooling tower with the ORC unit.

The solution

The Rank® HT1 system installed has an electric power of 10 kW with a nominal net electrical efficiency of 10%. A 3.5 m3/h pump transfers the heat transfer oil, which enters the evaporator at 200 °C and transfers heat until it diminishes its temperature to 165 °C. A secondary water circuit connects the ORC condenser to a cooling tower of 100 kWt capacity. The electricity produced by the ORC system covers 19% of the actual consumption of the ARCA Consortium offices. Therefore, it is a solution with high revenue since the ORC system represents only 18% of the initial cost.