This guidance note summarises cost benefit analysis of using solar shading. Three scenarios are modelled on different climate zones and each showed a payback for the solar shading of less than one year. The modelling shows that in general when a building has a glazing percentage greater than 50-60% it requires no extra investment for the installation of solar shading due to the savings in capital and operating costs of HVAC systems.
This analysis comes from Guidebook 12 produced by The Federation of European Heating, Ventilation and Air-Conditioning Associations (REHVA)
Download here: BBSA Guidance Note 20A – The Importance of Solar Shading in the Design of Air-Conditioning Systems