  While various nanophotonic structures applicable to relatively thin
crystalline silicon-based solar cells were proposed to ensure effective light
in-coupling and light trapping in the absorber, it is of great importance to
evaluate their performance on the solar module level under realistic
irradiation conditions. Here, we analyze the annual energy yield of relatively
thin heterojunction (HJT) solar module architectures when optimized
anti-reflective and light trapping titanium dioxide (TiO$_2$) nanodisk square
arrays are applied on the front and rear cell interfaces. Our numerical study
shows that upon reducing crystalline silicon (c-Si) wafer thickness, the
relative increase of the annual energy yield can go up to 11.0 %$_\text{rel}$
and 43.0 %$_\text{rel}$ for mono- and bifacial solar modules, respectively,
when compared to the reference modules with flat optimized anti-reflective
coatings of HJT solar cells.
