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.
