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Project overview
  • Lead Organisation

    Australian National University

    Location

    Canberra, Australian Capital Territory

    ARENA Program

    Research and Development

  • Start Date

    November 2014

    Status

    Current

  • Project Partners
    University of Colorado Boulder, IT Power Australia Pty Ltd

Summary

This project aimed to develop an innovative energy storage system that uses concentrating solar thermal technology to drive a high-temperature redox (or reduction-oxidation) thermochemical cycle.

Need

A technically feasible approach to the construction of a new concentrated solar thermal power system concept that involves a novel high-temperature thermochemical energy storage system was developed. This storage system promises to store thermal energy at temperatures of over 1,000°C, enabling the use of a combined power cycle, which reach the highest thermal power cycle efficiencies of up to 60% or more. The storage system is based on the reduction/oxidation cycling of a new mixed iron-manganese oxide thermochemical energy storage material.

A power system design concept was developed, including technical concepts for a two stage solar tower concentrating system, solar receiver-reactor for the thermal reduction step, oxidation reactor-heat exchanger for heat recovery, high-temperature particle storage tanks and material handling systems for particles and gases.

A literature review was conducted to compile data for the performance and cost of combined cycle power blocks. From this, the Levelised Cost of generated Energy (LCOE) has been determined. Based on the current cost-optimised system design with a 75 MW-e net power block and thermal energy storage system with 18 hours full-load storage capacity, an LCOE estimate of 224 AUD/MWh results (including 30% tax). This estimate is ~8% higher than that for a current state- of-the-art system.

Project innovation

This project aims to develop an innovative energy storage system that uses concentrating solar thermal technology to drive a high-temperature redox (or reduction-oxidation) thermochemical cycle.

The high-temperature reaction of the cycle stores high-temperature thermal energy within a redox material. At slightly lower temperatures another chemical reaction, called exothermic oxidation, releases the thermal energy for electricity generation.

The project aims to develop stable and durable redox materials that can deliver high reaction rates, as well as a prototype of the solar reduction reactor.

The solar reactor is an innovative ‘beam-up’ concept that minimises heat loss using a down-facing receiver to harvest the solar energy reflected towards it.

The system maximises the amount of energy generated, stored and released by carefully controlling the redox material and using a symmetric field of mirrors around the receiver.

Benefit

By being able to use higher operating temperatures, this technology has the potential to generate and store more energy than non-thermochemical storage systems. The new redox material will also provide a more efficient and responsive form of high-energy storage.

Last updated 17 July 2019
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