As electrification continues to gain momentum, the implications for system reliability will be profound. Not only is demand likely to grow, but daily and seasonal patterns of energy use may shift. The Midcontinent Independent System Operator, for one, has highlighted the need to “consider the simultaneous transformation of both generation and load to ensure system reliability.”

In this context, saving energy will continue to be valuable, but reducing use at times when energy is most in demand and costly will become increasingly important. 

Wisconsin is considering how to maximize the cost-effectiveness of its energy efficiency investments to meet this challenge. This policy brief, prepared for the Public Service Commission, shows that using more-accurate data and methods can enable the state’s energy efficiency program to emphasize demand savings equally with energy savings and begin the transition to a future where this data will be increasingly important.

Most energy efficiency measures simultaneously reduce both energy use and peak demand. Different measures, however, have different energy and demand savings characteristics. Using accurate, time-granular information reveals the relative size of the energy and demand savings and allows budget decision-makers to allocate program funding to measures with substantial demand savings. 

RAP conducted its research for this policy brief in four parts. The brief provides:

  • A summary of the current operational practices of Focus on Energy, Wisconsin’s statewide energy efficiency program, and an analysis of how changing the emphasis on demand and the time-varying value of energy can affect program planning, design and evaluation.
  • A synopsis of recent publications that address demand emphasis and time-varying value, both in Wisconsin and in the MISO region.
  • A review of the methods and tools that support programs in three comparable jurisdictions (Michigan, Oregon and Vermont) and an assessment of best practices.
  • An analysis of two specific measures — a solar array and a heat pump water heater — to illustrate the time-varying value of energy and capacity.
  • A fifth and final section assessing best practices and potential next steps.