Toward residential upgrade savings guarantees: An AMI-based diagnostic interface

Panel: 4. Monitoring and evaluation for a wise, just and inclusive transition

This is a peer-reviewed paper.

Authors:
Ethan Goldman, Resilient Edge, USA
John Theurer, Zither Labs, USA
Stephen Bickel, LibertyHomes, USA

Abstract

Residential weatherization and HVAC programs often struggle to deliver 100 % realization rates, but Inclusive Utility Investment programs such as Pay As You Save® (PAYS®) face a steeper challenge: to ensure that, barring changes in behaviour or new load, participants will all enjoy net bill cost savings. There are five primary reasons that expected savings are not fully realized even after weather-normalizing and adjusting for fuel cost changes: 1) changes in usage behaviour, 2) installation of appliances, 3) overestimated savings, 4) upgrades were not properly installed, 5) unrelated equipment failure. Even programs that deliver high energy savings realization rates will, due to the unavoidable occurrence of causes 1 and 2, will include projects where post-upgrade net energy savings are less than estimated and do not fully cover the fixed cost-recovery payments that are a feature of these programs. Although PAYS programs do not offer a savings guarantee, future Inclusive Utility Investment programs that wish to do so will need a means to manage that risk or at a minimum quantify the associated monetary risk so that it can be accounted for in program budgets.

In their quest to ensure that all participants are saving money, a rural electric cooperative is testing a new diagnostic tool designed for residential upgrade programs. The system is built on top of the open standard CalTRACK methods and provides physically meaningful model outputs such as changes in heating and cooling loads and balance points. This paper opens the hood of this new tool, showing how it analyses the hourly electric AMI data to generate charts and metrics that can automatically flag projects for review and help to identify what types of issues could be impacting performance. This paper also explains how the diagnostic system can identify early signs of potential deficiencies, such as misconfigured HVAC controls, determine if a fix is needed, and verify that any such issues are effectively remediated.