U.S. and China are the world’s top two economics. Together they consumed one-third
of the world’s primary energy. It is an unprecedented opportunity and challenge for
governments, researchers and industries in both countries to join together to address
energy issues and global climate change. Such joint collaboration has huge potential in
creating new jobs in energy technologies and services.
Buildings in the US and China consumed about 40% and 25% of the primary energy in
both countries in 2010 respectively. Worldwide, the building sector is the largest
contributor to the greenhouse gas emission. Better understanding and improving the
energy performance of buildings is a critical step towards sustainable development
and mitigation of global climate change.
This project aimed to develop a standard methodology for building energy data
definition, collection, presentation, and analysis; apply the developed methods to a
standardized energy monitoring platform, including hardware and software, to collect
and analyze building energy use data; and compile offline statistical data and online
real-time data in both countries for fully understanding the current status of building
energy use. This helps decode the driving forces behind the discrepancy of building
energy use between the two countries; identify gaps and deficiencies of current
building energy monitoring, data collection, and analysis; and create knowledge and
tools to collect and analyze good building energy data to provide valuable and
actionable information for key stakeholders.
Key research findings were summarized as follows:
1. Identified the need for a standard data model and platform to collect, process,
analyze, and exchange building performance data due to different definitions
of energy use and boundary, difficulty in exchanging data, and lack of current
2. Compared energy monitoring systems to identify gaps, including iSagy, Pulse
Energy, SkySpark, sMap, EPP, ION, and Metasys.
3. Contributed to develop a standard data model to represent energy use in
buildings (ISO standard 12655 and a Chinese national standard)
4. Determined that buildings in the United States and China are very different in
design, operation, maintenance, occupant behavior: U.S. buildings have more
stringent comfort standards regarding temperature, ventilation, lighting, and
hot-water use and therefore higher internal loads and operating hours, and
China buildings having higher lighting energy use, seasonal HVAC operation,
more operators, more use of natural ventilation, less outdoor ventilation air,
and wider range of comfort temperature.
5. Completed data collection for six office buildings, one in UC Merced campus,
one in Sacramento, one in Berkeley, one in George Tech campus, and two in
6. Compiled a source book of 10 selected buildings in the United States and China
with detailed descriptions of the buildings, data points, and monitoring
systems, and containing energy analysis of each building and an energy
benchmarking among all buildings.
7. Recognized limited availability of quality data, particularly with long periods of
time-interval data, and general lack of value for good data and large datasets.
8. Compiled a building energy database, with detailed energy end use at 1-hour
or 15-minute time interval, of six office buildings – four in the U.S. and two in
China. The database is available to the public and is a valuable resource for
9. Developed methods and used them in data analysis of building performance
for the five buildings with adequate data, including energy benchmarking,
profiling (daily, weekly, monthly), and diagnostics.
10. Recommended energy efficiency measures for building retrofit in both
countries. U.S. buildings show more potential savings by reducing operation
time, reducing plug-loads, expanding comfort temperature range, and turning
off lights or equipment when not in use; while Chinese buildings can save
energy by increasing lighting system efficiency, and improving envelope
insulation and HVAC equipment efficiency.
The research outputs from the project can help better understand energy
performance of buildings, improve building operations to reduce energy waste
and increase efficiency, identify retrofit opportunities for existing buildings, and
provide guideline to improve the design of new buildings. The standardized
energy monitoring and analysis platform as well as the collected real building data
can also be used for other CERC projects that need building energy measurements,
and be further linked to building energy benchmarking and rating/labeling