The energy-savings potential of a building is not equal across all buildings in a large portfolio, but buildings with the highest potential have an average energy-saving opportunity of 41 percent, according to a report from energy auditing software maker Retroficiency.
In the worst case, the savings opportunity is only 3 percent. Because of this range, organizations can benefit from prioritizing buildings with the greatest efficiency opportunities to meet goals and maximize their return, the company said.
The report, “Building Energy Efficiency Opportunity,” analyzes data from 500 randomly selected energy audits completed on Retroficiency’s Building Efficiency Intelligence platform.
Among its findings, the report finds that Energy Star and EUI building performance benchmarking systems should not necessarily be used to prioritize buildings based on their energy efficiency savings potential.
This is because Energy Star aims to rate building performance while factoring in use type, size, location, and other operational and asset characteristics. A high rating indicates a lower potential for efficiency improvements that will show a return on investment.
The EUI system, which measures energy consumption per square foot, is best applied when comparing buildings of the same use type. But offices with high EUIs are likely to have data centers. These data centers may have more limited savings opportunities, Retroficiency said.
The report also found that end uses that consume a small proportion of energy can offer large savings. For example, lighting, a common focus of energy efficiency projects because of its potential to provide a quick payback, accounts for a relatively small portion of current end-use consumption across most use types.
In contrast, about 50 percent of energy consumption stems from HVAC systems, but the proportion of HVAC-based savings do not always reach the 50 percent mark. Savings is not always aligned with the proportion of consumption, Retroficiency said.
Among its recommendations Retroficiency said that annual building savings can significantly increase if owners or managers are willing to raise their payback thresholds. For every one year increase from the mid-term to the long-term package, buildings could save an incremental 2.1 percent/year of energy.