Solar Absorber Aims to Make Solar Thermal Power Generation More Efficient and Affordable
The Masdar Institute of Science and Technology today announced the development of a high-performance solar absorber that could make solar thermal technologies significantly more efficient. Masdar Institute is part of the Khalifa University of Science and Technology.
The solar absorber, developed with the Massachusetts Institute of Technology (MIT), features an ultrathin nanocomposite film made of silver and silica, topped with silver nanoparticles. It absorbs nearly 100% of the sunlight’s energy from the ultraviolet and visible portions of the solar spectrum. This technological breakthrough could be a boon to the efficiency and affordability of solar thermal applications, such as utility-scale solar thermal power generation.
“The technology developed through this collaborative research effort demonstrates our commitment to generating innovations that will enable the UAE to achieve its diversified energy goals through sustainable solutions specifically targeted at advancing the energy sector. This research is also a testament to the Institute’s commitment to scientific rigor and excellence, which produces the intellectual and human capital critical to the country’s knowledge-economy transformation,” said Dr. Steve Griffiths, Interim Executive Vice President for Research at Khalifa University of Science and Technology.
A paper describing the team’s solar absorber was published in the journal Advanced Optical Materials this month. The research team that developed the absorber includes Prof. TieJun Zhang, from the Mechanical and Materials Engineering Department, postdoctoral researchers Dr. Jin You Lu and Dr. Aikifa Raza, and UAE National MSc students Afra S. Alketbi and Sumaya Noorulla, and from MIT, Prof. Gang Chen and Prof. Nicholas X. Fang, from the Mechanical Engineering Department.
The UAE is keen on implementing a range of solar technologies, including solar thermal, to help meet sustainability goals that include generating 44% of its electricity from renewable sources by 2050.
“The technology we have demonstrated is particularly attractive for hot-arid region, such as Abu Dhabi, with potential applications in waste water treatment, seawater desalination, and power generation,” Dr. Chen shared.
CSP is a type of solar power technology that generates electricity by concentrating sunlight to heat a working fluid, like oil or water, to produce steam for electrical power generation. The hotter the fluid is, the hotter will be the steam and hence the more efficient the power generation. In order to get the fluid as hot as possible, spectrally selective coatings are developed to enable solar absorbers to harness as much sunlight as possible while losing the least amount of energy in the form of infrared thermal radiation.
Using advanced microscopy tools to investigate the preliminary solar absorber design, the research team made an intriguing discovery about the nanocomposite absorber’s surface.
“Transmission electron microscopes enable us to see through the materials, beyond the surface and deep within the nanocomposite solar absorber,” Dr. Zhang explained. “With this vision, we observed that traditional solar absorbers, thought to be made of smooth, continuous composite layers, were actually filled with tiny nano-particles of each composite element and large nano-particles on the top surface. We discovered that it is the presence of these topping nano-particles that make absorbers more efficient. This knowledge became the basis for development of our nanocomposite film.”
The joint research team expects this discovery will boost the development of even more efficient solar collectors and in turn accelerate the development of more efficient and cost-effective CSP systems across the region and throughout the world.
“From the beginning, this project was focused on meeting the exact needs of CSP in the UAE. With support from the University-Industry Research Collaboration Award from the NRF, we were able to work closely with engineers at UAE’s 100MW CSP plant and Mr. Abdulaziz Al Obaidli, the general manager of Shams Power Company, to identify some of the key problems associated with solar energy production, and this helped us develop appropriate and regionally-relevant solutions needed to accelerate the performance of CSP systems in the UAE,” Dr. Zhang explained.
With the global CSP market value estimated at US$30 billion in 2017 and a cumulative installed capacity that could exceed 24GW by 2025 – which is nearly five times the current amount – there is a significant market for breakthrough technologies like the one developed through this joint collaboration that promise to reduce CSP system costs and improve power generation efficiencies.