Although most heat pumps use a motive force (electricity or gas) with a fossil fuel component they enhance the performance by extracting energy from Renewable sources. The key is to ensure over the annual cycle much more heat is produced than the primary energy used to drive the process. Heat pumps appear to defy the laws of physics with efficiencies over 100% i.e. delivering more heat energy than the heat energy they consume. This is because they are only conveying and upgrading existing heat from say the air or water, they are not ‘€˜creating’€™ the heat. As an analogy think of a heat pump conveying energy like a Petrol transporter conveys fuel to a Petrol station. Hopefully it uses far less energy to transport the fuel than the fuel it itself is transporting. Heat pumps work in a similar way, transferring energy from one source to another in an upgraded and more useful form.