Solar Thermodynamic Panels: Independent Test Challenge – Part II

Thermodynamic panel on test at Narec Distributed EnergyThermodynamic panel on test at Narec Distributed Energy

In April 2013 Narec Distributed Energy put out the Thermodynamic Test Challenge, this was an offer to test a system in our laboratory free of charge. The reasoning for this was that at the time (and currently) there is no independent test data of these systems in the UK climates. Test data exists for other countries with substantially different climates, but this information is of little value as being representative of UK conditions.

We received several interested enquiries, the first of which was from Hyrax Solar. On the 11th of December this system was finally installed in our thermal testing laboratory in Blyth. Monitoring will commence very shortly, with some sample data hopefully available before Christmas.

Thermodynamic systems are essentially air source heat pumps which take advantage of solar gain using a simple unglazed flat plate collector to supplement the energy taken from the ambient temperature of the air. The resulting temperature is upgraded using vapour compression (refrigeration) technology to heat the hot water in the tank to a suitable temperature for domestic hot water. The key question for industry is; how does the electricity used for the refrigeration system compare with the energy it takes from the air and solar gain? This is known as the Coefficient of Performance.

The test of the thermodynamic panel system will run from December 12th 2013 to the 31st May 2013. Tapping Cycle No.2 from EN 13203-2 will be used as the demand. This provides a typical but moderate domestic hot water energy use of 5.845 kWh/ day (around 120 litres). This cycle is well known to the boiler and heat pump industries.

Electricity consumption and delivered hot water energy will be measured at 2 minute intervals using tariff grade metering with pulse outputs. External ambient and test room ambient temperatures will be recorded using thermocouples, along with cold feed and hot water draw-off temperatures. The in-plane solar irradiance will be measured using a SP-lite pyranometer.

The test data will be published monthly on the Narec Distributed Energy website on the Thermodynamic Panel Test page

We hope this test will provide useful information to householders and industry about these systems.

For more information on Thermodynamic Panels, please check our Thermodynamic Panel Technology Page.