This paper analyzed the energy balance of extensive green roofs and presented a simple but practical
energy balance model. Field experiment justified the validation and accuracy of this model.
Experimental results demonstrated that within 24 h of a typical summer day, when soil was rich in
water content, solar radiation accounted for 99.1% of the total heat gain of a Sedum lineare green roof
while convection made up 0.9%. Of all dissipated heat 58.4% was by the evapotranspiration of the plants–
soil system, 30.9% by the net long-wave radiative exchange between the canopy and the atmosphere, and
9.5% by the net photosynthesis of plants. Only 1.2% was stored by plants and soil, or transferred into the
room beneath.