Low-Cost Solar Device Converts Sunlight to Steam in Dusty Environment

Low-Cost Solar Device Converts Sunlight to Steam in Dusty Environment
A bubble-wrapped, sponge-like device that soaks up natural sunlight and heats water to boiling temperatures, generating steam through its pores. Credit: George Ni at MIT

Scientists from Masdar Institute of Science and Technology in collaboration with Massachusetts Institute of Technology (MIT) have developed a novel and low-cost solar thermal energy conversion system. This new regime can efficiently convert 20% sunlight into steam at a temperature of 100 degree Celsius.

The device floats on water and converts incoming solar energy into steam without expensive optical concentration equipment. It is made up of cheap, readily available materials like bubble wrapper and plastic foam. This system allows scientists to generate steam with solar energy without the need of depending on direct sunlight.

Researchers explained, “the design of this device is very simple. A floating, sponge-like device made of a spectrally selective absorber allows visible light energy from the sun while restricting the amount of heat that radiates back out into the atmosphere. This heat-trapping effect significantly improves the device’s sunlight-to-steam efficiency.”

Dr. Steve Griffiths, Vice President for Research, said, “This project is an excellent demonstration of how international collaboration and use-inspired research can yield cutting-edge scientific findings that have direct application to the sectors that are at the core of the UAE’s continued evolution toward an innovation and knowledge-based economy.”

Dr. TieJun Zhang, Masdar Institute Assistant Professor, said, “The technology is particularly suited for the UAE’s dusty climate. It completely uses the entire spectrum of sunlight for thermal applications instead of the linear portion, which can be hinder by the aerosols.”

The absorber equipped in between a top bubble-wrap layer. It allows for sunlight absorption while minimizing heat loss amount by convection method. The bottom insulating foam layer reduces the thermal loss of the generated heat to the water below. The floating receiver mimics as a sponge that consistently soak water and evaporate it to produce a steam stream.

It can quickly reach 100°C and generate steam during periods of low direct sunlight. For example, during g non-summer months and heavy cloud coverage.

Dr. Chen said, “The technology is particularly attractive for the hot-arid region like Abu Dhabi for potential applications in wastewater treatment, seawater desalination, and even power generation.”