CPV: The CPV/T used is a solar collector that simultaneously generates the two most used forms of energy in the daily life: heat and electricity. This is possible, as it combines a photovoltaic panel and a solar thermal collector in the same module. It consists of a cylinder-parabolic reflector that concentrates the light of the sun ten times onto the receiver. The solar cells are optimized for concentrated solar radiation and each cell has 10 times more electric production than the same surface of standard solar cells, while they can be upgraded with more recent ones, as technology develops. The solar tracking system is controlled by a PLC control system to ensure that the collector follows the sun throughout the day and the focus is always on the solar cells.


ORC: An organic Rankine cycle (ORC) technology is used even more lately for the recovery of low-grade heat. The working fluid is a refrigerant, which can boil at temperature of even 60 oC, while the scale of such engines can be even of few kWs.

The ORC performance depends mainly on the evaporation/condensation temperature of the organic fluid (relevant to the heat source and heat sink characteristics respectively), while the selection of the proper organic fluid plays a key role in such applications, taking into consideration environmental criteria as well (e.g. ODP and GWP values).

Supercritical ORC shows some interesting features, such as a higher thermal efficiency under certain operating conditions and lower pinch-point temperature difference during the heat addition to the cycle, which means that a better exploitation of the available heat can be succeeded. These favourable characteristics lead to higher system efficiency, increasing the power output.



The objective of the proposed project is to extensively study the CPV/T-SCORC integrated process and to develop, construct and test a small-scale hybrid system with a capacity of 14 kWp, where CPV/T heat is effectively recovered by the SCORC process for electricity generation. A significant reduction of specific electricity cost is anticipated, reaching 0.12 €/kWh by the end of the project and even lower few years later, making the current technology competitive in the PV market and increasing significantly the competitiveness and business cycle of the involved SMEs. The participating SMEs are coming from Greece, Spain and Belgium.


The project “Improving the Performance of Concentrating PV by Exploiting the Excess Heat through a Low Temperature Supercritical Organic Rankine Cycle” deals with the development, design and experimental investigation of an integrated system, based on the concentrating photovoltaic (CPV) and supercritical organic Rankine cycle (ORC) technologies.

The proposed innovative concept deals with the conversion of the CPV/T heat to additional electricity through the Supercritical ORC (SCORC) process. SCORC is selected because enjoys better efficiencies at low temperatures in comparison to Subcritical ORC. This integrated CPV/T-SCORC system minimizes the temperature effect on the PV cells performance and improves the annual energy productivity (in kWh/kWp). In comparison to a flat PV system a performance improvement between 15-40% is anticipated, depending on the season, along with a more efficient heat transfer from the CPV/T system to the Rankine process (i.e. lower pinch point), due to the supercritical cycle.

The project duration is 24 months (start: January 2013) and is receiving funding from the European Union’s Seventh Framework Programme managed by REA-Research Executive Agency, ([FP7/2007-2013] [FP7/2007-2011]) under grant agreement n° 315049 [CPV/RANKINE], FP7-SME-2012.


The project video has been released and can be viewed here: