By Josh Perry, Editor
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Researchers from the University of South Australia (Adelaide) developed a system that uses renewable energy from solar or wind sources and a bed of rocks or phase-change materials to store thermal energy and can deliver industrial heat ranging from 150-700°C.

Researchers developed a thermal energy storage system using renewable energy sources and phase-change materials. (Wikimedia Commons)

According to a report from the university, the system differs from most thermal storage processes by not using a battery to store the energy but rather using electricity from renewable sources to generate heat that can be stored by phase-change materials.

The research team also claims that the system would be economical as well as sustainable. The components are basic, reducing the cost of installation, and they are easily maintained or replaced.

A prototype of the system is located at the Barbara Hardy Institute at Mawson Lakes (Australia) and a second version is being developed for full commercial operation.

The research was recently published in Renewable Energy. The abstract read:

“In the current study the feasibility of using solar-based renewables coupled with thermal energy storage (TES) to displace gas for heating was explored. To assess the feasibility, a numerical model of an air-based encapsulated phase change (EPCM) storage system was developed, validated, optimised, and economically costed.

“The optimised air-based EPCM system utilised a high and low melting temperature phase change material (PCM) with a sensible storage filler. It was found that a capsule radius of 10?mm and PCM volume of 13% resulted in the lowest cost of discharged thermal energy of $25.55/kWh when storage effectiveness and pumping power was considered.

“This system was then coupled to solar data for Adelaide, South Australia, to simulate the performance of a 1?MWt heat load over a year. By solving an hourly system generation and demand profile, it was found that a concentrated solar thermal (CST) and photovoltaic (PV) system coupled with TES was able to economically reduce gas consumption by 45–65% when the price of gas was $30/GJ.

“By employing near-term cost estimates for CST and PV systems coupled with TES, it was found that gas consumption could be reduced by similar amounts with a gas price of $20/GJ.”