Sand could be the key to unlocking more efficient concentrated solar power

Masdar Institute scientists have published breakthrough research that could change the way solar energy is produced.

They hope to drive concentrated solar power technology to compete with traditional photovoltaic solar power using nothing more than the most abundant material found in the UAE — sand.

Named “Sandstock”, the research published at the Solar Power and Chemical Energy Systems Conference in South Africa on Tuesday, showed that sand is capable of withstanding temperatures of up to 1,000 degree Celsius.

Concentrated solar power, CSP, uses mirrors to reflect heat from the sun to a concentrated point, most typically a tower filled with a material capable of storing heat and then converted into electricity.

The benefit of CSP is that the energy derived from the technology is easy to store, however in recent years the CSP has lost the battle to the more popular photovoltaic because of its better cost efficiency — but that may change with the recent findings.

“Sand is really always a drawback in this country, but in this project we wanted to use it as an advantage because it can withstand very high temperature and of course it is very cheap here,” said Dr Nicolas Calvet, assistant professor at the Department of Mechanical and Materials Engineering and the guide for the research project.

He said that in CSP, scientists and his PhD students working on the research are always looking for materials capable of withstanding higher temperatures.

“The higher you can push your temperature the more efficient your plant will be in generating electricity,” he said. “With sand we can push it to 1,000 Celsius and it’s available,” said Dr Calvet.

The argument for CSP is that it is significantly more efficient than photovoltaic at storing energy after sunset. Again, the Masdar researchers are finding potential in sand’s capability of storing energy.

“Basically you heat up the sand during the day, and at night when you don’t have sun you can use the heat from the sand to continue to generate energy, which is not possible with PV because it is too expensive to store at this moment,” he said.

The current limitation for conventional CSP systems is capped at 600 degrees Celsius as molten salt, the most common material today, begins to degrade beyond that point.

?Sand, they found, is capable of storing energy at 400 degrees more than molten salts.

Read more: Sand could be the key to unlocking more efficient solar power, Masdar scientists find