Distributed Energy Resources
Bills and Rates

Distributed Energy Resources Rate Calculator

This spreadsheet model can help our public power utility members assess the potential impacts of distributed energy resources (DER) on utility revenues and customer rates.

The tool is meant to provide a high-level overview that illustrates key rate design dynamics (i.e., the interactions among volumetric charges, customer or fixed charges and demand charges), and shows indicative results that can convey a quantitative sense of how DERs, at different levels of penetration, are likely to affect both utility-wide rates and rates for non-DER customers.

The spreadsheet abstracts from many details in order to provide a quick overview without requiring substantial data gathering or preparation, and it is not intended to be a comprehensive rate-making device that sets aside the need for more rigorous analysis.

Based on user inputs for key utility characteristics (fixed and variable costs, peak load, diversified demand, kWh sales and DER penetration), the spreadsheet calculates impacts of the DERs on utility-wide average rates and average rates to non DER customers and allows the user to do what-if analyses related to cost recovery through different rate components. The worksheet shows how DERs, at different levels of penetration, can create revenue shortfalls, and it also shows the potential rate impacts for non-DER customers (i.e., cross-customer subsidy) if their rates increase to enable recovery of lost revenues.

The tool also allows users to input, and evaluate, different rate design options. For example, one can lower volumetric charges and then determine by how much customer or demand charges would have to increase to offset the revenue reduction and provide for adequate cost recovery.

Download the spreadsheet.

View a video tutorial about the spreadsheet.