'Electrocaloric' material could lead to more efficient refrigerators

A team at the National Physical Laboratory (NPL) is trying to develop the first practical ‘electrocaloric’ cooler, providing much greater efficiencies than conventional gas-based refrigeration systems and without the high costs of using large magnets to generate low temperatures.

The NPL engineers are hoping to take advantage of a breakthrough made in 2006 when scientists showed the electrocaloric effect, which causes materials to change temperature under an applied electric field, was much larger in thin film substances than in bulk solids and big enough for its use in cooling applications.

‘It is has taken us until now to develop the understanding to take this to a stage where we can develop a real cooler, but we believe we are now at that stage,’ lead researcher Tatiana Correia told The Engineer by email.

Typical domestic fridges use a continuous cycle of vapour compression and expansion of chemicals such as Freon that condense into liquid and absorb heat from the surroundings. These chemicals can be harmful to the environment and such systems have fairly low efficiencies of around 30 per cent.