Saving energy along with reducing carbon emission is an unavoidable new trend in response to continual global warming. In Taiwan, the energy consumed by commercial buildings and residential houses accounts for about 18% of the total energy consumption with 31% consumed for HVAC (heating, ventilation, and air conditioning) to emit 21 millions of carbon dioxide annually. Hence, in this research, an integrated energy-saving system combining green architecture, recirculation and reuse of water resources, indoor plants to purify indoor air quality, and solar energy and hydrogen energy is proposed for providing HVAC and illumination. The research has accomplished the following: (1) roof-top plants will lower the indoor temperature during summer; (2) utilizing aquatic plants to purify the wastewater for recirculation and reuse will effectively remove BOD and COD from contaminated water; (3) indoor plants are effective in lowering loadings to air conditioners and energy consumption; (4) the solar air conditioner has excellent overall energy saving features; (5) the solar hydrogen generating system and reformed methanol system have been developed applied to develop a 100 W PEMFC (proton exchange membrane fuel cell); and (6) a portable plant cultivation system has been developed to enhance plant growth for removing indoor carbon dioxide so that the building needs not be ventilated much to maintain adequate indoor air quality.
