Measuring persistence of energy savings after COVID-19

Abstract

Publicly funded energy efficiency projects require measurement to inform climate and energy policy, craft program budgets, and determine the cost-benefit ratios of different projects. One of the key inputs into cost-benefit analyses is the concept of an effective useful life, or EUL. This value, typically measured in years, lets programs and policy makers estimate how many years the energy savings will last. For most programs, this measurement is done based on manufacturing assumptions, i.e. the laboratory determined that an LED lightbulb would last for 10,000 h, or 15 years. New programs, using a methodology known as “advanced measurement and verification (AM&V)” measure the EUL using a survival analysis of the savings. We ask the question, “At what point will this project be savings less than 50% of what it saved on day 1.” We measure the energy consumption of a facility at the meter level to determine how much energy is being used compared to when the measure was installed. COVID-19 has thrown a wrench in the ability to compare energy use across years. Not only is there a disruption from COVID-19 directly, but entire industries have fundamentally changed the way that they operate their buildings and run their businesses. We are able to extract out the impacts of COVID for many of our building’s models, but not all. Using methods derived from independent, third-party evaluators, we have developed a new way to measure the ongoing persistence of energy savings using self-report data from participants at the project level, rather than at the savings level. Doing this will allow us to compare the data from pre-COVID with the new world full of post-COVID data, and to assess the true impacts of COVID on the energy efficiency industry’s most basic cost-effectiveness assumptions.