Google parent group Alphabet has unveiled plans for new thermodynamic technology that could store renewable energy for weeks at a time in molten salts or antifreeze-like liquids.

Alphabet’s X division – its so-called ‘moonshot’ research arm – said it is at an advanced design stage with the technology, which has been developed under a project called Malta.

The system would see renewably-produced energy stored at scale in tanks of high-temperature molten salts or liquid coolant, before being reconverted to electricity via heat-exchange technology.