Owners of such “green” buildings as Tesoro Corporation’s headquarters building, in San Antonio, have not had real-life data on energy efficiency and cost savings until recently, when a database was developed to enable owners and developers to compare the costs of specific energy-saving methodologies versus their real-life performance. Wikimedia Commons/uniquebuildings
A new database that is being created in California aims to quantify the benefits and risks of making energy-efficiency improvements to buildings.
July 23, 2013—While many building owners and investors have embraced energy-efficient technology and retrofits as a way to lower costs and help the environment, some have remained reluctant due to a perceived lack of reliable data on how often and to what degree such improvements achieve their touted benefits. That is why researchers at the Lawrence Berkeley National Laboratory in California are developing a first-of-its-kind Buildings Performance Database (BPD) that uses real data from more than 60,000 buildings throughout the United States to gauge actual energy performance and show how energy-saving technology is paying off.
Scientists have been working on the database for nearly three years, in conjunction with Portland, Oregon-based software developer Building Energy Inc. They have collected records from various companies and government sources that detail the age, size and use of thousands of commercial and residential buildings, as well as information on their lighting, heating and cooling systems, and energy usage. The project, which is being sponsored and managed by the U.S. Department of Energy (DOE), is designed to continue growing in coming years into an ever-expanding database that uses real data to complement the models and simulated data that are currently the most-used predictors of energy performance.
Researchers hope that the database will help building owners better gauge their energy performance against similar buildings, and give both owners and investors a better idea of how infrastructure improvements can help and which ones are most effective. “You need data on buildings—both their characteristics and their energy use—to try and figure out these relationships,” says Paul Mathew, Ph.D., the lead researcher on the project and a staff scientist in Berkeley Lab’s Environmental Energy Technologies Division. “We have some basic tools to explore the data and see what’s there, but then we envision a range of different stakeholders accessing the data and doing their own analysis with it.”
Mathew says the idea for the database came in response to calls from the financial community for better data on the benefits of energy upgrades. Many investors said they were interested in financing energy-efficiency projects—which can bring cost savings and a return on investment—but that standard models and simulations typically offered only a single-point estimate of energy and cost savings, but failed to articulate a range of likely savings or quantify the risk of a project falling short of its projected performance.
Elena Alschuler, a building technologies program specialist for the DOE’s Office of Energy Efficiency and Renewable Energy, says the lack of risk-quantifying metrics has been especially disconcerting to investors because they typically rely heavily on risk-based analysis when making investment decisions. “What they really want to understand is that performance distribution, and that’s what’s not been available,” she says. “You’d want to diversify that portfolio to minimize your risk, and in order to do that you need lots and lots of empirical records about real buildings.”
In their search for empirical records, researchers have collected building data from a broad range of sources, all of which have cooperated on a voluntary basis. The BPD contained more than 66,000 records as of this summer—with 10,000 more records waiting to be processed—from organizations ranging from real estate investment groups to the Kohl’s department store chain to the U.S Environmental Protection Agency’s voluntary ENERGY STAR program. Identifying information on each building, such as its address, is removed, and researchers plan to continue adding new building records as they come in.
The records include such building characteristics as gross floor area, age, and hours occupied, as well as such performance metrics as site and source energy-use intensity for electricity and fuels. When accessing the database, building owners can compare their properties to buildings with similar characteristics and analyze the possible benefits of retrofits such as new lighting or HVAC systems.
Collecting the data has not come without difficulties, as Mathew says researchers have worked hard to cleanse, validate, and standardize the thousands of records that have arrived in different formats and on types of media ranging from paper to a variety of computer programs. Alschuler says data have revealed some trends in the performance of similar buildings, but that there is not yet sufficient data from some building types and geographic locations to fully analyze trends regarding the effectiveness of energy efficiency upgrades. As the database expands, it will become more useful in helping stakeholders better understand what Mathew calls the “scatters”—the wide range in findings—and identify more concrete trends.
“It wasn’t consistently one way or the other, and that can create this perception of risk around energy efficiency,” Mathew says. “We need to make a concerted effort of understanding where that scatter comes from … This is a marathon, not a sprint.”
Alschuler reiterates that while the BPD is already a useful tool, it is still a work in progress. She says that while virtually all of the records contain information on building characteristics and overall energy use, only about one-third of them list the types of energy equipment inside the building. She says this currently limits the database’s ability to establish firm connections between certain upgrades and improved performance, but that she expects the quality of data to continue improving as more records come in.
“When you start to gather that information, then you can start to understand why buildings are high and low performers, and the relative contribution of these different characteristics to overall energy performance,” she says. “The value of the Buildings Performance Database is going to depend upon an engaged community of energy efficiency professionals that contribute data.”