In a significant advancement for the solar energy sector, researchers have conducted a comprehensive study comparing the use of molten salts and thermal oil in parabolic trough power plants, revealing crucial insights into their cost-effectiveness and operational efficiencies. Led by Jürgen Dersch from the German Aerospace Center (DLR e.V.), the study meticulously analyzed the levelized cost of energy (LCOE) across different geographical sites and thermal storage capacities, aiming to optimize the economic viability of solar thermal power.
Parabolic trough solar thermal power plants harness sunlight through parabolic mirrors that concentrate solar radiation onto a linear receiver, where it is converted into thermal energy. Traditionally, thermal oil has been the go-to heat transfer fluid (HTF) for these systems, but its limitations—such as a maximum operating temperature of 400 °C—have prompted researchers to explore alternatives like molten salts. The study highlights that a ternary salt mixture, with a temperature range of 170 °C to 500 °C, consistently yielded the lowest LCOE across various sites and storage capacities.
Dersch emphasizes the importance of this finding, stating, “The results indicate that molten salts, particularly the ternary mixture, can significantly reduce energy costs, making solar thermal power more competitive with other energy sources.” This assertion is particularly vital as energy markets increasingly seek sustainable solutions to meet growing demands while reducing carbon footprints.
The research also addressed operational challenges associated with molten salts, including their higher melting temperatures, which necessitate careful management to prevent solidification. The study suggests innovative freeze protection strategies, utilizing heat from thermal storage to mitigate risks associated with lower temperatures. This approach not only enhances operational reliability but also positions molten salt systems as more adaptable to varying climatic conditions.
The implications of this research extend beyond mere cost comparisons; they signal a potential shift in how solar thermal power plants are designed and operated. By demonstrating that molten salts can outperform traditional thermal oils, especially in regions with high direct normal irradiance (DNI), the study opens avenues for more efficient energy generation. For instance, in high-DNI regions like Morocco, the ternary salt configuration shows substantial advantages over thermal oil, paving the way for more economically feasible solar projects.
As the energy sector grapples with the dual challenges of curbing emissions and ensuring energy security, findings from this study, published in the journal ‘Energies’, could catalyze a new wave of investment in solar thermal technologies. By optimizing the use of molten salts, energy developers may find themselves better equipped to meet regulatory demands and consumer expectations for greener energy solutions.
In a market that is rapidly evolving, the insights provided by Dersch and his team will likely influence future developments in solar thermal power, encouraging further research and investment in molten salt technologies. The study underscores a pivotal moment for the energy industry, where innovative materials and methods could redefine the landscape of renewable energy.
