A new type of photovoltaic window with high transparency is described. The high transparency is achieved by incorporating the photovoltaic cells in the panel perpendicularly to the plane of the panel. The predicted performance i.e. electrical output and solar heat gain coefficient (SHGC) versus time of day are derived for a photovoltaic window panel on different facades of a building. Measurements of power output and SHGC for a prototype panel are obtained at specific times of day are compared with the predicted performance.