Counting Time: New Tool Estimates the Value of Efficiency, Solar, and Other Distributed Resources Based on When They Save Electricity

Most investment decisions for energy efficiency and solar consider only electricity and dollar savings over the course of a year. But the value of these measures—and other distributed energy resources (DERs)—varies hourly. That’s because the cost of generating, transmitting and distributing electricity during peak hours is significantly higher than during lower load hours for most U.S. regions. 

Yet electricity planning and programs across the United States often miss this temporal element. Berkeley Lab’s Time-Sensitive Value Calculator is designed to assist state public utility commissions, state energy offices, utilities, and stakeholders estimate the hourly value of efficiency, solar, and other DERs. Knowing when DERs are saving energy or generating power, and the hourly value of the energy and demand savings to the electricity system, provide key information needed to procure the optimal amount and type of these resources. 

The value of DERs changes over the years. The Time-Sensitive Value Calculator allows users to consider value under various future scenarios. For example, users can input multiple measure shapes — from their own data sources or the recently released ResStock and ComStock end use load profiles — that represent advances in building controls and shift electricity consumption to lower-cost time periods. Changes to the utility’s or region’s power plant mix may result in higher or lower values for DERs, and users can assume different hourly costs for eight unique years to better understand the changes in values. 

Users can enter into the Calculator hourly profiles for up to six measures at a time. The tool monetizes their value for six value streams: avoided electric energy; deferred generation, transmission and distribution capacity; carbon emissions; and electric system risk mitigation. Outputs include tabular and graphical formats. The graph below shows an example output — the net present value (NPV) of six illustrative energy efficiency programs in Texas over their lifetime, by value stream. 

Illustrative example of the time-sensitive value of six efficiency programs in Texas.

The Calculator produces five additional outputs: annual value by year, hourly value for a user-defined day, hourly value for an average day in each selected year, hourly value for an average day in each month and year, and electricity system shape and selected measure shape for a user-defined day to compare measure and system load shapes. 

The Time-Sensitive Value Calculator and user manual can be downloaded at https://emp.lbl.gov/publications/time-sensitive-value-efficiency.

Natalie Mims Frick, JP Carvallo, and Margaret Pigman in Berkeley Lab’s Electricity Markets and Policy Department created the tool and wrote the user manual. The Building Technologies Office of the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy supported this work.

Berkeley Lab is presenting a free webinar on April 13, 2022 to discuss and demonstrate this new tool for electricity decision-makers and stakeholders. You can register for the webinar and learn more here: https://lbnl.zoom.us/webinar/register/WN_5ls4liJpQT2OOVpxOZ5qqg.