What is a molecular solar thermal energy storage system?

photoisomers are referred to as molecular solar thermal energy storage systems (MOST), also known as solar thermal fuels (STF). In this review, we introduce the functional principles and criteria of a general MOST system, then introduce to a broad audience three key candidates and show the efforts made so far to achieve recent advances in results.

Can molecular photoswitches be used to store solar energy?

Recent advances in the design of molecular photoswitches have opened up opportunities for storing solar energy in strained isomeric structures and releasing heat on demand, culminating in molecular solar thermal (MOST) energy storage densities over 0.3 MJ kg −1 and validating the potential for achieving thermal battery applications.

What are solar thermal batteries based on?

The solar thermal batteries based on MOST compounds will enable a solar-chargeable, off-grid, and long-term energy storage in light-weight organic materials that are easily produced from low-cost feedstocks, complementing the state-of-the-art energy conversion and storage technologies.

How can a solar system absorb thermal energy from a photoisomerization?

An alternative strategy is to combine solar energy from photoisomerization with latent heat from phase transitions. Using this approach, MOST systems can also absorb thermal energy from the local environment in addition to the stored solar en- ergy.

How can solar energy be stored?

Nature can store sunlight via photosynthesis with an efficiency between 0.1%–0.3%,5 leading to biomass production. Artificially, solar energy can be stored as chemical energy, e.g., via electrochemical water splitting for hydrogen production.

How can solar energy storage technology be improved?

In the first mode, the objective will be to reach a stable thermal output, while in the second mode larger temperature gradients will be targeted under shorter durations of time. This work will help to advance solar energy storage technology.