For anyone with an interest in chemistry, I recommend the scientific paper.

https://www.science.org/doi/10.1126/science.aec6413

Trying to think of critiques:

• the wavelength of light necessary to "charge up" pyrimidone is fairly short (300 nm, UVB ultraviolet light)

• the quantity of UVB light on Earth's surface is limited (it is mostly absorbed by the ozone layer)

• however, one can artificially produce ultraviolet light from solar electrical power, or figure out molecules that charge with UVA or even blue light, which would be perfect

Positive aspects:

• pyrimidone looks simple, synthesis probably is not hard
• it is solid at room temperature
• it lasts long when charged
• it is compatible with a water environment when energy needs releasing

Addition of hydrochloric acid (HCl) to Dewar pyrimidone (107 mg in 0.46 ml of water) increased the solution temperature to 100°C and induced boiling within 1 s, demonstrating rapid macroscopic heat transfer to an environmentally benign medium under ambient conditions.

Subsequently, the solution can be neutralized with an alkaline chemical, pyrimidone can be "recharged" and the cycle repeated. The summary of the article does not mention how many cycles it endures. I would be good to know that.