World’s Most Efficient Solar Power System Might Be Almost Here

published Oct 12, 2015
1 min read


Swedish firm testing a new revolutionary solar dish

For the past four years, the Kalahari desert in South Africa has been the playground of a team of developers that claim to be working with the most efficient solar power system ever created. Massive, 100m2 rotating mirrors have been installed in the Northern Cape region and manage to convert 34% of the sunlight they receive into electricity. A remarkable feat, considering that solar panels currently on the market hardly reach a 20% level of solar efficiency. The power generated by one solar dish would be enough to power more than 20 houses a year.

The project’s genesis

The project has its roots in military technology and has been used extensively by the navy before being adapted for commercial use. The system works by reflecting the light and concentrating it into a small target that powers an engine. The dishes incorporate a tracker that follows the sun’s movements, allowing the system to catch all of the sunlight available in a day. Usually, Concentrated Solar Power (CSP) systems work by converting the concentrated sunlight into heat, which powers a steam engine. The market for these plants is growing rapidly, especially in regions with large unused land and good insulation, such as the Middle East. The idea behind the technology is thousands of years old: the ancient Greeks were probably the first to use sunlight and mirrors to light enemies’ ships on fire. The innovative engine (called the Stirling engine) used by Ripasso, the Swedish firm behind the new project, was developed in the 19th century using heated gas instead of steam, but was too advanced for that time. It wasn’t actually used until the 80s, when the navy started implementing the technology for submarines. The CEO of Kockums, the company behind those submarines, resigned and started Ripasso when he realized that the powerful engine could have much broader applications and could contribute to making solar electricity systems more powerful. However the company has yet to find a way of making it price competitive and efficient in areas that don’t receive as much sunlight as an African desert.

The road to commercialization

Ripasso has proved that their system works but has gone through some trouble to obtain funding, having received several refusals from banks. Now, the company has found private contractors and claims to be ready for commercialization. Their technology, compared to traditional CSP systems, is more space-efficient and doesn’t require water, which is needed in large quantities to cool other CSP plants. However lowering costs won’t be easy considering how fast solar panels’ prices are dropping. Driving down costs requires economies of scale and widespread adoption, but high efficiency might not be enough to achieve that if not paired with low costs. If the new CSP system is proven to be a good alternative and is adopted by a large audience, costs will decrease, just like those of solar panels. In fact, when they were introduced in the late 70s, solar panels were a hundred times more expensive than they are today, and the same might happen to new technologies.

Read More: Solar Power Thrives in the Middle East