This factory’s massive mirror array turns sunlight into thermal energy

A massive industrial plant in Belgium using 2,240 parabolic mirrors to harvest sunlight to create green heat is officially open. At 5,540 square meters (roughly 18,175 square feet), the site’s Concentrated Solar Thermal (CST) platform and six-module thermal storage unit is the largest of its kind in Europe, according to manufacturing company Avery Dennison.

In basic terms, the facility takes sunlight, reflects it into heat-absorbing oil, and then utilizes the oil to help supply the plant’s thermal energy needs.

Over half of the entire world’s energy consumption stems directly from manufacturing industries—meaning that these companies must adopt sustainable infrastructures to avert climate change’s worst outcomes. The European Union, in an attempt to spur such reforms, passed legislation in 2021 which set net-zero emissions targets across all its industries by 2050. As such, Avery Dennison’s new attempt at progressing towards that goal leverages direct sunlight as a substitute for fossil fuel heating systems.

The installation generates the same thermal power that can be achieved using 2.3 GWh of gas consumption, but is expected to reduce the facility’s overall emissions by an estimated 9 percent annually. During the warmer summer months when less heat is needed, however, the new system is expected to offer 100 percent of any necessary demand.

[Related: Could aquifers store renewable thermal energy?]

To convert solar rays into heating fuel, the CST platform’s curved mirrors first reflect light towards a collector tube filled with an absorption liquid such as thermal oil. This heated oil is then stored within a specialized installation similar to a giant thermos, whose heat is distributed as needed and on demand like a battery. Scaling up to six “battery” modules totalling 5 MWh of thermal power storage ensures the system can emit high temperature heat whenever required.

Among other products, Avery Dennison manufactures adhesive tapes and labels for uses across the automotive, medical device, personal care, and construction industries. According to the company, most of the vast array’s generated heat will be directed into drying ovens used during the coating process of pressure-sensitive adhesive products.

“We have big ambitions to tackle climate change and achieve net zero by 2050,” Mariana Rodriguez, general manager of Avery Dennison Performance Tapes Europe, said via the company’s announcement. “To meet these goals we will look across our industrial processes and identify opportunities to implement new technologies that decarbonize and reduce our reliance on fossil fuels.”

Thermal power storage is showing increasing promise as a cheap, sustainable way to meet industries’ heating needs. In recent years, new research indicates methods such as utilizing silica sand and even underwater aquifer water could offer effective means for housing thermal energy.