Robustness of hybrid power plants under long-term weather and market fluctuations

Abstract

The impact of weather variations on the electricity market was simulated using Balmorel for 30 weather years (1986-2015). These market conditions were then applied to test the financial robustness of hybrid power plants (HPPs) in HyDesign. Prices follow a seasonal pattern and are significantly influenced by weather, exhibiting a negative correlation with solar and wind generation. Additionally, solar and wind resources themselves are negatively correlated. When one resource (e.g., wind speed) decreases, the other (e.g., solar irradiation) tends to increase, and vice versa. HPPs demonstrate greater financial robustness over the long term, exhibiting less variation and outperforming single-technology plants in terms of net present value (NPV). This increased stability is primarily attributed to reduced production variability, greater participation in energy markets, more efficient utilization of grid infrastructure, and lower costs achieved through synergistic effects. The main driver behind the reduced variability is the decreased dependency on a single renewable energy source. Several HPP design configurations with varying shares of wind and solar capacity can achieve comparable long-term financial performance and outperform single-technology plants. Notably, each weather year may have its own optimal HPP design. However, planning HPP designs based on multiple weather years is crucial, as the optimal configuration can vary significantly over time, ranging from pure solar or wind setups to various hybrid configurations. Over the long term, HPP designs consistently demonstrate stable and robust financial performance. However, this conclusion assumes sufficient wind and solar resources at the plant location and the possibility of overplanting the point of connection (POC). Under current battery technology costs and tested electricity market conditions, no batterybased design was selected during optimization. Not all potential aspects of HPPs have been explored, such as participation in various electricity markets like automatic Frequency Restoration Reserve (aFRR) and Frequency Containment Reserve (FCR), or all possible design configurations of HPPs, including combinations of solar, wind, hydropower, biomass, and hydrogen production.