# Solar cells that work underwater

> A perovskite panel tuned for blue light hit 35 percent efficiency 10 meters down in the South China Sea.
- Title: Solar cells that work underwater · Ars Technica | Shortify
- Summary: A perovskite panel tuned for blue light hit 35 percent efficiency 10 meters down in the South China Sea. Perovskites can be tuned to the wavelengths that…
- Keywords: solar, perovskite, ocean tech, energy, materials, technology, science, cells, work, underwater, Ars Technica
- Source: Ars Technica — https://arstechnica.com/science/2026/09/a-new-solar-cell-could-generate-electricity-underwater
- Published: 2026-09-14T18:03:16+00:00
- Read time: 1 min
- Topics: solar, perovskite, ocean tech, energy, materials, technology, science
## Sunlight below the waves
A team led by Simin Ma at Yunnan University built perovskite solar cells designed to run underwater, where ordinary silicon panels go dark.
## Perovskites trade power for life
They are cheap, flexible, and convert more sunlight than silicon. The catch is that they degrade fast, and moisture is the worst offender of all.
## Tune the cell to blue
Water swallows the wavelengths silicon needs, but perovskite chemistry can be retuned to catch what remains a few meters down. Dimmer, cooler conditions also slow the decay.

> a carefully designed perovskite cell could still make electricity in the deep blue sea
## One additive, three jobs
Polyhexamethylene guanidine hydrochloride wraps the material in a water-repelling layer, grows larger crystals, and pins ions in place. Durability and output both improved.
## 35 percent at ten meters
Under light filtered to mimic a 10 meter depth, the cells turned about 35 percent of it into electricity. Silicon panels sit closer to 20 percent.
## Forty days in seawater
A sealed panel held 99.6 percent of its efficiency after 40 days submerged, pointing to a 5.5 year useful life. In the South China Sea it charged coin cells at 2, 6, and 10 meters.

> autonomous marine power systems and submerged Internet of Things infrastructure
## Key takeaway

Perovskites can be tuned to the wavelengths that survive underwater, and a single additive fixed the moisture problem well enough to make submerged solar practical for sensors and drones.