0312 Executive Digest.IR 2

Electric Power Research Institute (EPRI)

This paper describes a methodology the Electric Power Research Institute (EPRI) has developed to model the marginal carbon dioxide emissions impact of energy efficiency.

Though energy efficiency is intuitively recognized to reduce carbon emissions, one barrier to its broader application is the lack of precision in attributing emissions reductions to specific program activities. Coarse estimates based on utilities’ average emissions factors, while straightforward to calculate, do not provide enough specificity on emissions reductions at the margin.

Key points to keep in mind about this paper include:
The EPRI methodology allows utilities to compute more precise estimates by focusing on the impact of energy efficiency by specific end use (such as residential lighting, commercial space cooling, etc.) on marginal CO2 emissions, which takes into account how much energy is saved when.

Power plants of different types (e.g., nuclear, coal, gas, renewables, etc.) are ramped up and down daily to meet the changing demand for power in a given region. As the composition of electricity generation in a given region changes, so does the rate of CO2 emissions. The typical method of applying the average emissions rate of electricity generation for a given region or service territory does not take into account how CO2 emissions rates change over time.

The EPRI approach takes into account the characteristic end-use load shape of an energy efficiency measure specific to a given region to distinguish the type of generation and hence intensity of emissions that is avoided at the margin. It uses a sophisticated EPRI model that simulates the dispatch of electricity generation at the regional level to meet forecasted demand. By running simulations with and without a given energy efficiency measure, the model isolates the impact of that measure and provides a more rigorous computation of its emissions impact.

The power of this approach lies in the ability to distill complex model simulations into simple CO2 intensity factors (measuring tons of CO2 avoided per megawatt-hour reduced) for energy efficiency that are specific to particular regions and types of end uses. An implementer of energy efficiency programs, such as a utility, can multiply its energy efficiency savings by the corresponding intensity factors to quantify CO2 emissions reductions.

In addition, EPRI has developed a user-friendly calculator as part of this research to provide its members with a way to analyze and assess scenarios of how their energy efficiency programs affect CO2 emissions.

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0312 Executive Digest.IR 2

Electric Power Research Institute (EPRI)

This paper describes a methodology the Electric Power Research Institute (EPRI) has developed to model the marginal carbon dioxide emissions impact of energy efficiency.

Though energy efficiency is intuitively recognized to reduce carbon emissions, one barrier to its broader application is the lack of precision in attributing emissions reductions to specific program activities. Coarse estimates based on utilities’ average emissions factors, while straightforward to calculate, do not provide enough specificity on emissions reductions at the margin.

Key points to keep in mind about this paper include:
The EPRI methodology allows utilities to compute more precise estimates by focusing on the impact of energy efficiency by specific end use (such as residential lighting, commercial space cooling, etc.) on marginal CO2 emissions, which takes into account how much energy is saved when.

Power plants of different types (e.g., nuclear, coal, gas, renewables, etc.) are ramped up and down daily to meet the changing demand for power in a given region. As the composition of electricity generation in a given region changes, so does the rate of CO2 emissions. The typical method of applying the average emissions rate of electricity generation for a given region or service territory does not take into account how CO2 emissions rates change over time.

The EPRI approach takes into account the characteristic end-use load shape of an energy efficiency measure specific to a given region to distinguish the type of generation and hence intensity of emissions that is avoided at the margin. It uses a sophisticated EPRI model that simulates the dispatch of electricity generation at the regional level to meet forecasted demand. By running simulations with and without a given energy efficiency measure, the model isolates the impact of that measure and provides a more rigorous computation of its emissions impact.

The power of this approach lies in the ability to distill complex model simulations into simple CO2 intensity factors (measuring tons of CO2 avoided per megawatt-hour reduced) for energy efficiency that are specific to particular regions and types of end uses. An implementer of energy efficiency programs, such as a utility, can multiply its energy efficiency savings by the corresponding intensity factors to quantify CO2 emissions reductions.

In addition, EPRI has developed a user-friendly calculator as part of this research to provide its members with a way to analyze and assess scenarios of how their energy efficiency programs affect CO2 emissions.

Click here for report