Techno-economic assessment of 1TW Solar and wind system with thermal and pumped hydro energy storage in Saudi Arabia

Saudi Arabia boasts abundant solar and wind energy resources spread across its vast geography, offering renewable energy at lower costs compared to many parts of the world. However, achieving 100% utilization of these resources faces significant challenges due to daily and seasonal variability. While daily and hourly variations can be managed with energy storage batteries, seasonal variations are particularly challenging, making it difficult to incorporate these renewable sources at a high percentage in the energy mix. This study explores Saudi Arabia's potential to export 100% renewable energy, focusing on solar and wind power, by leveraging Pumped Hydro Energy Storage (PHES) and Thermal Energy Storage (TES). It evaluates the country's wind and solar resources, estimates freshwater needs for large-scale PV projects, and assesses the feasibility of PHES across various provinces. The authors propose preliminary sizing for a 1 TW solar and wind system that integrates both thermal and pumped hydro storage, optimizing solar site selection and capacity to minimize monthly variations. The research includes assessments of wind and solar resources in Saudi Arabia, storage methods for large solar and wind energy fractions, and a cost and startup-time comparison of utility-scale storage methods. It also identifies potential PHES locations and provides preliminary sizing for the 1 TW solar and wind system, including optimized solar site and capacity selection to minimize monthly variation. Additionally, the study offers an optimized arrangement of the daily operations of the proposed solar, wind, TES, and PHES system to achieve the lowest possible cost. The findings suggest that Saudi Arabia can export nearly 100% of its solar and wind energy, even during nationwide rain or dust storms, with minimal biofuel use. It has the potential to export 1 TW of continuous renewable electricity, equivalent to over 24 million oil barrels, at a cost of less than $36.83 per equivalent oil barrel. The required land area for solar is approximately 137,000 km2 (6.4% of total land), and for wind, it is about 73,333 km2 (3.4% of total land), which can be integrated with solar fields. The water needed for washing solar panels is around 13.7 million cubic meters per day. The land requirement for PHES ranges from 1000 to 3000 km2, with water needs between 1 and 3 million cubic meters per day, depending on elevation differences. The land requirements for Thermal Energy Storage are much smaller and can be easily integrated within the solar and wind farms.