The effect of HelioPod™ mobility on concentrated solar thermal project economics

Abstract

The production of heat for industrial processes is one of the significant contributors to greenhouse gas emissions, with the mining and minerals processing industry in South Africa as a substantial user of high-temperature process heat. South Africa produces 80 % of the world's manganese. The sintering of manganese in South Africa is fossil fuel intensive and emits nearly a million and a half tons of CO₂ per year. Concentrating Solar Thermal (CST) produces heat that can be utilised at a significantly lower cost than diesel firing, which is currently used for sintering. However, with CST being a nascent technology, most mining operations are reluctant to commit to its use. These risks can be minimised for the customer using an Energy Supply Company (ESCo or energy-as-a-service company) to provide heat to the mine.

For the ESCo, one of the most significant risks is the potential for the mining customer to terminate the contract before the end of the life of the CST energy supply asset. Using a solar field based on heliostats, such as the HelioPod™, that can be redeployed presents a level of insurance against this risk. In this analysis, the economic advantage of the HelioPod™ solar field-based CST system is compared to that of a conventional permanent pedestal-based heliostat field. The comparison was made assuming early termination of the contract and scenarios where the CST facility was redeployed once or twice during the nominal life of the facility. The discounted cash flow analysis shows that reusing the heliostat field leads to significant economic improvements. The study shows that the conventional permanent heliostat system reduces the project NPV@7 % by up to 28 % compared to the HelioPod™ system with one move in the project's life.