Innovative low-carbon home heat storage system trialled

A heat storage process using a mineral commonly found in washing powder has shown promising results in an innovative low-carbon trial programme.

In the system, heat is used to dry thousands of zeolite beads, which are used in a wide variety of applications such as in laundry detergent, cat litter and for the absorption of radioactive leaks. The beads drive off water, which is then separated and condensed.

Adding the water to the dried beads generates heat in a reversible process. Furthermore, the beads can cool to ambient temperatures without losing storage capacity.

Made of a new class of zeolites, the pressed beads have a higher energy capacity than previous materials.

In the trial system, sized to simulate demand by a single-family household, two low-pressure vessels each filled with 750kg of zeolite beads reach temperatures above 75°C when discharged, suitable for domestic use. One vessel is used on a day-to-day cycle while the other simulates seasonal storage processes.