Should you install thermodynamic panels on your home?

They are touted as a free source of clean, unlimited energy to heat your water but the first independent test suggests they are not as efficient as thought

Thermodynamic panels have been touted as "a free source of natural, clean and inexhaustible energy providing 100% of your hot water needs, 365 days of the year". For around 5,000 to buy and install, they sound too good to be true - and the first independent tests suggest they are.

Thermodynamic panels are similar to air-source heat pumps and work like refrigerators in reverse.