The largest solar concentrator in the world has 500 m² of area with 380 mirrors to supply a hospital.
Photovoltaic energy is not only breaking records in Spain and the European Union, but also in the rest of the world. Emerging powers, mainly from the BRICS+ group, are betting on this means. The latest innovation has been the largest solar concentrator on the planet, capable of supplying an entire hospital.
Operating at full capacity for more than a year, with an apotheotic size, “SG4 Big Dish” and installed in India, this innovative concentrator reformulates the climate policies applicable around the planet, and especially within the healthcare industry.
It’s time to see how and to what extent.
What is a solar concentrator and how does it contribute to the efficiency of renewables?
These types of devices, usually large in size, focus sunlight on a small area to generate high temperatures that can be used to produce electricity.
Focusing reflected radiation from a wide area onto a smaller solar receiver increases the power density reaching the receiver. Although in Spain they are not so common due to the more than 2,500 hours of sun, in other countries they are essential.
Solar concentrators use curved lenses or mirrors to concentrate and focus direct solar radiation into a focal region. A receiver is placed at the focus that absorbs the highly concentrated irradiation.
Importantly, a solar concentrator is typically used to reach much higher temperatures than conventional photovoltaic cells, making them more efficient at converting solar energy to electricity.
SG4 Big Dish. Nick-D, CC BY-SA 4.0, via Wikimedia Commons
SG4 Big Dish: the largest solar concentrator in the world
If until now you had never heard of SG4 Big Dish, you will soon hear about it often since it is, as we said, the largest solar concentrator in the world, with a reflective surface of 500 square meters.
Developed by the Australian company RayGen Resources, it weighs 26 tons and consists of a large 25-meter-diameter parabolic mirror made up of 380 individual parabolic mirrors. Each of these mirrors is hexagon-shaped and has a reflective surface of 1.52 square meters.
These mirrors are designed to concentrate sunlight onto a thermal collector located at their focal point, similar in function to a giant pot for boiling water or other fluids. Thus, the 380 mirrors cover an area of 500 square meters, the largest reflective area ever achieved in a solar concentrator.
Its reflective plate is made of polished aluminum and has a thin layer coating that gives it a reflectivity of 94%, thus maximizing the amount of solar radiation that can be reflected and concentrated in a single focal point.
The tracking precision of the solar concentrator is also key, using a dual-axis system with electric motors that allow it to follow the path of the sun with a precision of 0.01°, the highest and which has even surprised Tesla.
“The 380 mirrors of SG4 Big Dish cover an area of 500 square meters, the largest reflective area ever achieved in a solar concentrator.“
Generate enough energy to power a hospital and a research center
In early 2023, western India became home to the world’s largest and most efficient solar concentrator.
This facility, not only impressive in size but also in capacity, has been designed to power a hospital and a research center, marking a milestone in the utilization of solar energy for practical and sustainable applications.
A key feature of this project is the implementation of Kipp & Zonen’s RaZON+ system, developed by OTT HydroMet. This cutting-edge solar tracking device allows the “Big Dish” to be aligned with the path of the sun, thus optimizing the capture of direct solar irradiation.
This precision is essential to maximize the efficiency of the entire installation.
The SG4 Big Dish not only stands out for its impressive size and efficiency, but also for its practical impact. It has the capacity to generate 400 kg of steam per hour, which is equivalent to cooking 2,000 meals a day, in addition to meeting the hospital’s laundry and sterilization needs.
This steam is also used to generate electricity through a turbine, demonstrating the versatility of the system.
Despite technological advances, the project faces challenges, such as variability in solar radiation due to cloud movement. To counteract this situation, it is crucial to have systems that monitor and adjust concentrator operation based on these variations.
In this context, OTT HydroMet and its RaZON+ system from Kipp & Zonen play a key role.
This system not only measures direct, global and diffuse solar irradiation, but can also be integrated into a complete weather station, thus offering a comprehensive solution for solar tracking.
How much power can SG4 Big Dish generate?
The SG4 Big Dish solar concentrator is capable of generating a large amount of energy due to its innovative and efficient design. Thus, this solar concentrator can generate up to 150 kW of power.
This represents a significant advance in efficiency compared to other solar concentrators, as many conventional solar thermal systems only achieve 15-20% efficiency.
Furthermore, by focusing sunlight on a small area, very high temperatures are reached, on the order of 500 °C, which makes it possible to drive a high-performance heat engine to generate electricity for an entire hospital.
As we see, photovoltaic energy does not only depend on plates and batteries. A solar concentrator like this, of dimensions never seen before, is key to taking advantage of photovoltaic radiation in areas with fewer hours of light per year.