There has been a lot of discussion recently of the heating technology known as solar thermodynamic panels (or solar-assisted heat pumps). In Ireland they are often marketed as solar panels or a “solar panel that works at night”. In fact they are actually a type of DX heat pump, which uses a roof mounted evaporator to extract energy from the air and sun, slightly different to a standard air source heat pump using a fan to draw air over a matrix of finned tubes. This type of misinformation has caused many customers to be mis-sold a product they thought were solar panels. Ireland.
Narec Distributed Energy became interested in the claims by different thermodynamic solar panels manufacturers, some of which seemed incredibly ambitious, since no solar thermodynamic panels appeared to be based on verifiable test data for a solar panel system. They thought it would be interesting to test a system and post the results publicly, something we welcome.
Narec issued a challenge through their website asking a manufacturer to provide and install a solar thermodynamic system and they would test the system for free and post the results online monthly. A UK manufacturer accepted the challenge and installed a thermodynamic solar panel system in December 2013. The heating of domestic hot water is the sole purpose of the thermodynamic solar panels Ireland.
The goal of the test is to determine the Coefficient of Performance (COP) of a thermodynamic panel system under UK weather conditions – this should be fairly equivalent to the weather conditions in Ireland. The COP is the comparison of the amount of energy used by the thermodynamic solar panel system (pumps, compressor, etc) against the energy delivered to the hot water load. It is worth noting that this is a test for heat pumps specifically and not solar thermal panels.
The system is currently under test in the Narec Distributed Energy Test Lab in Blyth, UK. This lab has been used for various heating technology tests, including boiler efficiency, energy saving flow restrictors, and using solar thermal panels with combi boilers. They are well placed to perform an objective test of thermodynamic solar panels Ireland.
In order to ensure that the test is representative of a domestic consumer a Tapping Cycle representing a domestic hot water load of a four-person household is used. This tapping cycle ensures the hot water load is 5.845 kWh per day; the actual volume of water drawn depends on the inlet and outlet temperatures. This means the thermodynamic solar panels ireland system will provide the same amount of energy every day making it testable.
In order to understand the efficiency of the water tank and immersion within the thermodynamic system, the test was run for four days without the panel input. This allowed us to measure the efficiency of the water tank alone, so that we could separate the impacts of the solar panels Ireland.
Since January 2014 the results have being posted on their website
The thermodynamic solar panel system average basic COP for January is 1.02 rising to 1.36 in April. This is slightly less costly than using an electric immersion to heat water. Daily hot water tank temperature averaged 52.6°C. They have not seen the COP of 7 claimed by some manufacturers of thermodynamic panels.
Even without the summer data, we can see that the thermodynamic panel returns approximately twice the energy of an immersion heater this means that thermodynamic systems are maybe half the cost of using an electric immersion to heat your water. This technology may be suitable for people using an electric immersion to heat water or maybe oil but obviously there are other competing, more established low carbon technologies to consider such as solar thermal which would have a greater return than thermodynamic solar panels. irela
You can see actual solar panels prices here