I consider these as a form of air source heat pump, without a fan or finned coils. The underlying technology is well established and should be as reliable as a GSHP.
The panels are a good solution for a marine environment – I wouldn’t use ASHP units near the sea as the coils rot after about 7 years due to salt corrosion, so they would be a cheaper alternative than GSHP for such areas.
I have seen a completed installation and the owners were very happy with it.
Solar thermal it ain’t however – there is an improvement in COP when the sun is shining but it won’t provide free energy.
As far as I can find there are two manufacturers of these systems, the best known being Energie in Portugal http://www.energie.pt/ but also a company called Energy Panel in Spain. http://www.energypanel.es/productos.aspx?idFamilia=1&idProducto=1
The problem I have with them is a seeming lack of independent verification of their claims for running costs. I’ve seen mention of various installations being independently monitored but all my previous efforts to get these reports have so far failed.
Does anyone know of any such independent verification?