Will Virtual Energy Audits Replace Physical Audits?

One of the consequences of social distancing due to COVID - 19 has been a proliferation of virtual energy audits. Such audits rely on a combination of interval data from electric meters and phone or online surveys to produce Energy Efficient Measures (EEMs) for a given facility. Proponents of such audits point to recent developments in “big data” analytics techniques to make a case for “robust analysis” using interval figures from smart meters. Smart meters typically produce 35,000 data points in a single year. Virtual energy audits incorporate data from other sources, such as public data and building data, to produce analysis and a holistic picture of the audit. 

Harvesting this data can generate interesting insights and patterns about usage. In addition, the data also provides benchmarks against other, similar structures in the vicinity and city. Because they do not require onsite visits or extensive observation and interviews, such energy audits can be conducted relatively quickly and cost significantly less as compared to their physical versions.

But they might not be as effective. According to a 2016 study published by the American Council of Energy Efficiency (ACEEE), virtual energy audits can often miss the best EEMs. This is primarily because they work with a limited number of data points and do not take observations and on-site tests into account. 

“...the specifics of the problem on hand are not known, so savings and cost estimates are based on a range of values,” the study’s authors write. The overall result is that the owner may end up spending money on futile or inefficient initiatives.  “This inaccuracy (in data points) makes it difficult for the facility owner to determine which EEMs would be most cost-effective to implement, again with the result that, the facility owner, heeding the advice of the virtual audit may end up implementing EEMs that in reality have higher simple paybacks, while those with lower simple paybacks are overlooked,” the authors write. 

They have a point. Virtual energy audits cannot substitute for first-hand observation or experience. Consider the process to test the efficiency of a steam boiler. That process consists of a combustion safety test and processes to measure pressure, identify heat loss points, and checking the efficacy of insulation. Simply knowing a steam boiler’s age (through a phone interview) cannot help auditors identify its problems. Smart meter data also may not be granular enough to make reasonable deductions about its efficiency. 

This does not mean that virtual audits do not serve a purpose. As sensors and connected devices become common throughout the grid and building structures, virtual audits will help drive down overall costs to achieve energy efficiency by supplying program administrators and utilities with valuable data regarding usage. To that extent, virtual home energy audits might be a useful supplement, rather than a replacement, for physical home energy audits. The current jump in virtual audits is an opportunity to possibly fine tune the process by identifying gaps in it.