Using Renewable Electricity, Energy Storage, and Renewable Fuel to Produce Carbon-Neutral Process Heat and Power

In the pursuit of lower and more stable energy expenses coupled with lower carbon emissions, the industry is moving towards the integration of low-cost renewables. This can be achieved through a range of technologies and/or mechanisms, each with its own set of advantages and disadvantages. One potential solution to achieve low-cost, predictable, and low-carbon process heat and power is the coupling of renewable electricity with thermal energy storage backed up by renewable fuel. This combination takes advantage of the low-cost but variable renewable generation coupled with the dispatchability of thermal energy storage with robustness added by utilizing a higher cost but low volume renewable fuel. With this approach, a lower overall cost, dispatchable, robust, and carbon-neutral solution to process heat and power is realized. Therefore, in the current study, several combinations of renewable technologies coupled with electrically charged thermal storage (ECTES) and renewable fuel were designed and simulated to meet the process heat needs of two hypothetical scenarios. The solutions were then evaluated based on their economic (levelised cost of heat and power) and environmental (carbon emission avoided) merits to determine feasible solutions. Of the two studied cases, replacing diesel for heating at a mine site with solar PV, wind, ECTES, and renewable diesel delivered significant financial and environmental benefits. Unfortunately, at today’s prices replacing natural gas heating with solar PV, ECTES, and biomethane is not economically feasible without further cost reductions and/or a carbon tax.

Keywords: Biofuels, Carbon-Neutral, Process Heat, Renewable Integration, Thermal Storage.