ARKANSAS, Oct 6 (Future Headlines)- As the world races toward a more sustainable and renewable energy future, the integration of clean energy sources into the electricity production landscape is a top priority. Among the many strategies available, pumped hydro-energy storage (PHES) is emerging as a valuable asset in optimizing renewable energy utilization and enhancing the overall efficiency of power systems. Researchers from the University of Zaragoza and Atalaya Generacion in Spain have developed an optimal hourly management model that integrates grid-connected photovoltaic and wind power plants with reversible pump-turbine units. The goal is to maximize the monthly operating profits of the energy system while meeting electricity demand, thus ushering in a greener and more sustainable energy landscape.
Pumped hydro-energy storage is poised to transform the electricity production and supply chain landscape by adding substantial value to every link in the process. This transformation is essential for addressing the pressing challenges of renewable energy integration and reducing reliance on fossil fuels, including gas and oil. The capacity of PHES to store excess energy and release it when needed positions it as a vital component in the transition toward cleaner and more sustainable energy systems.
To harness the potential of PHES effectively, the researchers have formulated a techno-economic dispatch model, which serves as a mixed-integer optimization problem. This model is designed to maximize the utilization of renewable energy resources, specifically wind and solar power, in conjunction with the capabilities of reversible pump-turbine units. By optimizing the energy system’s operation on an hourly basis, the aim is to achieve the twin objectives of maximizing operating profits and fulfilling electricity demand.
The study’s findings offer valuable insights into the significant advantages of integrating renewable energy sources with PHES. The model excels in maximizing the utilization of wind and solar resources. In more than half of the months of the year, over 70% of electricity demand can be met by stochastic renewable sources and hydroelectric storage, significantly reducing dependence on the conventional grid.
PHES emerges as a pivotal tool in maintaining grid stability. Technical grid constraints that can lead to energy rejections or curtailments during periods of high renewable energy generation are mitigated by the inclusion of storage. PHES helps minimize these disruptions. The integration of photovoltaic and wind energy sources with PHES not only enhances efficiency but also grants the facility valuable management capabilities. This leads to an improved generation profile and overall system efficiency.
The combination of renewable energy sources and PHES translates into cost savings. The study reveals that purchasing energy in the electricity market can be reduced by up to 27% compared to scenarios without storage while still meeting electricity demand. PHES serves as a safeguard against energy curtailment risks. In the model incorporating PHES, the maximum energy generated by renewable plants is utilized in each hour. In contrast, scenarios without storage result in a 17% reduction in wind power generation and an 8% reduction in photovoltaic generation.
While this research marks a significant step toward optimizing renewable energy integration with PHES, further enhancements and refinements are warranted. Specifically, researchers should explore the incorporation of variable efficiency values within the operating range of reversible pump-turbine units. This adjustment could potentially enhance the accuracy of assessments and further improve system performance.
The findings of this study underscore the pivotal role of energy storage, particularly PHES, in facilitating the transition to a sustainable and renewable energy landscape. PHES not only enhances grid stability and efficiency but also enables the seamless integration of renewable energy sources, reducing reliance on conventional fossil fuels. As the world seeks innovative solutions to combat climate change and embrace clean energy, the integration of renewable resources with PHES offers a promising path toward a greener and more sustainable future. The results of this research have been published in the Journal of Energy Storage.
Reporting by Kevin Wood; Editing by Sarah White