Identifying optimal photovoltaic technologies for underwater applications

TL;DR

This study introduces a simple bench-top method to evaluate photovoltaic technologies for underwater use, comparing silicon, CdTe, and GaInP cells under simulated underwater spectra to identify optimal options at various depths.

Contribution

The paper presents a novel bench-top characterization technique for underwater photovoltaic evaluation that avoids the need for water tank testing during early development stages.

Findings

GaInP cells achieve over 51% underwater efficiency at depths > 2 m.

Silicon cells outperform others under terrestrial sunlight conditions.

CdTe and GaInP outperform silicon at greater depths.

Abstract

Improving solar energy collection in aquatic environments would allow for superior environmental monitoring and remote sensing, but the identification of optimal photovoltaic technologies for such applications is challenging as evaluation requires either field deployment or access to large water tanks. Here, we present a simple bench-top characterization technique that does not require direct access to water and therefore circumvents the need for field testing during initial trials of development. Employing LEDs to simulate underwater solar spectra at various depths, we compare Si and CdTe solar cells, two commercially available technologies, with GaInP cells, a technology with a wide band gap close to ideal for underwater solar harvesting. We use this method to show that while Si cells outperform both CdTe and GaInP under terrestrial AM1.5G solar irradiance, both CdTe and GaInP outperform Si at depths > 2 m, with GaInP cells operating with underwater efficiencies exceeding 51%.