Bifacial photovoltaics at high latitudes can achieve up to 25-45% bifacial gain due to high-albedo snow cover and high proportion of diffuse light. We studied the angular performance of bifacial silicon heterojunction solar cells with various textures to understand high-latitude effects on optical losses. For cone and pyramid-patterned designs, external quantum efficiency decreases at high angles, primarily due to increased reflectivity, although longer path length through front-surface films also increases UV losses for all surface types. At 80° incidence and 25°C, a <7% reduction in short-circuit current due to change in external quantum efficiency is observed for random pyramid textured surfaces. Simulation is compared to measured external quantum efficiency for a silicon heterojunction cell, and similar trends are observed with increasing angle of incidence. A relative reduction of <1% in short-circuit current is also observed when moving from an air mass of 1.5 to 5 at high angles of incidence. These results will inform future solar heterojunction designs for this application and be applied to refine annual energy yield calculations.