UCSB researchers report record solar-thermal energy storage density using DNA-inspired molecules

Researchers at the University of California, Santa Barbara (UCSB) say they have developed a molecular solar thermal (MOST) energy storage system that achieved an energy density of 1.65 megajoules per kilogram, according to a study published in February.

The approach uses DNA-inspired molecules that change shape under ultraviolet (UV) light to store energy, then release heat when triggered to return to their original form. In a laboratory demonstration, the team released enough heat to rapidly boil a small amount of water.

How the system stores and releases energy The UCSB system relies on molecules that contort when exposed to 300-nanometre UV light, storing energy in a strained configuration. The stored energy can later be released by prompting the molecules to revert to their initial shape using hydrochloric acid.

Limitations and next steps Despite the record energy density—described in the source as higher than that of lithium-ion batteries—the current setup faces practical constraints.

One issue is that the activation wavelength depends on what the source describes as “very harsh” UV light, which is present in natural sunlight only in small amounts. Another is that the release trigger used in the demonstration was corrosive hydrochloric acid, which would need to be neutralised asourceser use.

The researchers say future work will focus on improving responsiveness to natural light and developing a non-toxic way to trigger heat release. The longer-term aim is a clean, storable heat source that could support efforts to decarbonise heating.