Sustainable Products, Projects and Green Design Photosynthetic City Biomass Power System by Wenkai Xue Photosynthetic City is a combined solar and biomass energy system designed for existing city buildings. Solar panels on steel frames are mounted on the roof, while planting modules made of recycled injection molded plastic cover the building surface. The planting modules have small holes that guide excess rainwater downward, so every plant receives water and nutrients. Plant waste is collected and burned in a combined heat and power steam turbine to produce electricity. The plants also store carbon, clean the air and reduce noise, lowering the demand for traditional energy.