China’s Gobi Desert Solar Thermal Plant
China’s solar thermal station in Guazhou County—built by China Three Gorges Corporation—features two 200-meter towers, each connected to a sprawling field of approximately 27,000 mirrors (heliostats). These mirrors concentrate sunlight onto the towers, generating intense heat that reaches up to 570°C, which is then stored and used to produce steam for energy generation even after sunset or during cloudy weather.
The dual-tower system is a technological upgrade: the east tower operates during the morning, while the west tower maximizes afternoon sunlight. This design boosts overall thermal efficiency by up to 25 percent compared to the traditional single-tower plants. With partially overlapping mirror fields, total mirror requirements are reduced—a crucial factor since mirrors comprise nearly 60% of construction costs.
This Guazhou plant is a key part of China’s clean energy hub in the region. It is integrated with substantial solar PV and wind farms, aiming to supply power for approximately half a million households annually. Unlike earlier standalone projects in Europe and the US, this Chinese plant benefits from a broader, interconnected energy strategy.
How a Solar Thermal Power Plant Works
A solar thermal power plant harnesses concentrated sunlight to generate electricity via a multi-step process:
Solar Concentration: Thousands of mirrors track the sun and reflect its rays onto a central receiver atop a tower.
Heat Storage: The concentrated light heats a fluid or salt in the receiver, reaching high temperatures for latent heat storage.
Steam Generation: The stored heat is used to produce steam from water.
Electricity Generation: Steam drives turbines linked to generators, converting mechanical energy into electricity.
Extended Generation: The ability to store heat allows the plant to supply power when the sun isn’t shining, overcoming intermittency issues.
Pros of Solar Thermal Power Plants
Energy Storage: Can deliver electricity after sunset and during cloudy spells, unlike standard photovoltaic (PV) panels.
Grid Stability: Helps stabilize energy supply and complements intermittent sources like wind and PV solar.
Scalability: The multi-tower system opens the door for bigger, more efficient future projects.
Environmental Benefit: Reduces carbon emissions by relying on solar energy instead of fossil fuels.
Cons of Solar Thermal Power Plants
High Mirror Costs: Mirror fields account for most of the plant’s cost, requiring precise manufacturing and maintenance.
Land Usage: Vast installations need significant, flat land—often limiting possible sites.
Initial Investment: Upfront costs remain steep despite long-term efficiency.
Weather Dependency: While heat storage offers resilience, lack of sunlight for extended periods still affects performance.
Competition from PV: The rapid decrease in photovoltaic panel costs globally has challenged thermal projects, causing many to struggle financially in the past.
Global and Future Perspective
China’s solar thermal push consists of 21 commercial plants (totaling 1.57 million kW) and over 30 new projects under construction, which will add another 3.1 million kW. Its integrated clean energy model is being replicated worldwide in places like Morocco and Chile, where solar thermal forms part of larger national energy strategies. The largest operating complex globally is the Noor Energy 1 project in the UAE (700 MW), where China also played a key development role.
China’s Gobi Desert solar thermal plant is a bold step in clean energy engineering, demonstrating how advanced storage, dual-tower designs, and integration with broader renewable grids can address both cost and intermittency challenges. While the upfront expenses remain high, solar thermal technology offers vital solutions for a stable, low-carbon energy future.