To fill these research gaps, this paper aims to develop a GIS-based energy balance modeling system for urban solar buildings. It integrates the building energy modeling and solar modeling to provide energy consumption and production estimates, as well as the energy balance using the self-supply ratio (solar energy production/energy use) and surplus ratio (surplus solar energy/ energy use). Its advantages include:
- System boundary: It extends the system boundary from a single building to the urban area, with the consideration of the influence of shadings effects, microclimate changes and occupancy variations.
- Data source: It uses available urban-scale data instead of painstaking survey data of individual buildings, with complementary information from the reference building database.
- Platform: As a widely used informational tool in planning and urban policy making to manage urban scale spatial data, GIS is used in this modeling as the platform to organize, analyze and visualize data.
- Speed and accuracy: To deal with large amounts of data at the urban scale, it aims to find a good balance between speed and accuracy, by reducing the resolutions to a certain acceptable level.