Analysis of the Energy Saving Potentials for Near-Zero Energy Buildings in Shanghai

The Changning District in Shanghai has expressed interest to becoming a green neighborhood and has asked for recommendations on how to reduce the energy usage in public buildings in their district. The objective of this short study is to identify the likely range of further reductions in the energy use and carbon emissions of new buildings through energy-efficiency improvements and the use of renewable energy, i.e., solar hot water (SHW), photovoltaics (PV), and ground-source heat pumps (GSHP), as compared to buildings that meet the current public building energy code in Shanghai. This analysis is done using DOE-2.1E computer simulations of three prototypical building models — an office, a hotel, and a mixed-use retail/office building — that have been calibrated against measured energy data from such buildings in the Changning District. After the building models have been calibrated, they are then used to establish the baseline energy use for code-compliant buildings, and to calculate the energy savings for 16 potential EEMs (Energy Efficiency Measures) that exceed the building energy code. A LCC (Life-Cycle Cost) analysis is done to compare the energy cost reductions to the capital costs for the EEMs, with the result that some EEMs are rejected as being not cost-effective over a 25 year period. The usage of the EEMs accepted as cost-effective is found to reduce the energy usage of the three building types by 30–40% in the office, 43–46% in the hotel, and 35% in the retail, depending on the assumed discount rate. If all the EEMs are considered regardless of cost, the energy savings increase to 44% in the office, 47% in the hotel, and 36% in the retail.Copyright © 2011 by ASME