CSP: Solar Breakthroughs from South Africa to the Mojave Desert

ENGIE is among the global companies that have been applying Concentrated Solar Power (CSP), a technique that uses mirrors to concentrate sunlight and convert it into heat, which is considered by some experts to be a potentially history-changing breakthrough in solar energy development.    

HELIOGEN is a U.S.-based company touting what it says is just such a cutting-edge solar solution.

The startup recently came out of “stealth mode” — having actively avoided publicity during six years of development — to announce that they have invented a new technique to use CSP to produce cement. This is no small feat: 

- Their 400 robotic heliotrope mirrors in the Mojave desert are able to generate heat above 1800°F, the range of difficult to generate temperatures needed to produce cement. 

- With double the carbon footprint of the airline industry, the cement sector accounts for 8% of worldwide emissions and had been hard pressed to find clean energy solutions

- It’s a potential momentous technology that could revolutionize the construction industry, and has garnered widespread media attention and the financial backing of Bill Gates.

- Heliogen’s challenge now is to scale their products and prepare for commercialization. 

SOLPART was the first company to demonstrate that CSP-generated heat could be used for industrial purposes, with another approach to try to maximize solar energy capture:

- Using the world’s largest solar furnace, they designed and tested two different cement reactors, both of which worked.  

- While Heliogen uses AI to make sure its mirrors are always at the right angle, Solpart uses one enormous parabolic mirror that is 17 stories high. 

- They plan to open a cement plant that’s partially solar powered in Spain by 2025.           

- Solpart is currently working on finding a suitable way to store surplus solar energy so they can continue making cement even when the sun isn’t shining. 

KATHU is a solar park in South Africa that has the potential to produce 700 cubic meters of concrete a day. It is ENGIE’s first foray into CSP:     

- The park’s molten salt storage system can provide up to 4.5 hours of thermal energy when there isn’t enough sun.

- The 4.5 km² plant with 384,000 parabolic mirrors began commercial operations in early 2019, making it one of South Africa’s largest renewable energy projects.   

- In addition to cement creation, the park will deliver energy to 179,000 homes in nearby municipalities.