integrated resource planning
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Integrated Resource Planning for Electric Utilities

Integrated resource planning for electric utilities forecasts 20 years of load, generation, and rates. See the framework and where software fits.
Written by
Neal Gudhe
Published on
April 26, 2026
Updated on
July 5, 2026

Integrated resource planning (IRP) for electric utilities is a long-range planning document, typically 15 to 30 years forward, that combines load forecast, generation supply, demand-side resources, transmission, and rate impact into a single least-cost portfolio submitted to the state public utility commission. Most investor-owned electric utilities file an IRP every two to five years; electric cooperatives, municipal utilities, and federal power marketers file voluntarily or under wholesale supplier requirements. A modern IRP integrates AMI hourly load data, demand response, distributed energy resources, and clean-energy mandates into the same model the utility uses to decide which generating units to build, retire, or contract for.

The IRP filed this year shapes capital allocation for the next two decades. Getting it wrong is expensive both ways: overbuild and ratepayers overpay; underbuild and the utility imports power at spot prices or sheds load.

This guide explains what an IRP is, who has to file one, the six components, the steps to build one, the supporting software, and how CIS and billing data feed the load forecast. Electric utilities running CIS, billing, and AMI on a modern cloud platform should look at SMART360 for electric utility management, which produces hourly load shapes by customer class that any credible IRP forecast depends on.

Who has to file an integrated resource plan

IRP filing requirements vary by utility type, state, and wholesale relationship. The pattern across the United States:

  • Investor-owned electric utilities (IOUs) are required by state law in most states to file every two to five years. The IRP is reviewed in a contested proceeding with intervenors and is binding on major capital decisions.
  • Electric cooperatives that take wholesale power from a G&T cooperative often have their IRP obligations met at the G&T level. Distribution co-ops that self-supply file their own.
  • Municipal electric utilities generally are not required by state PUCs but often file voluntarily or under federal supplier requirements. Public power agencies in California, Washington, and Oregon file under state mandate.
  • Federal power marketers (BPA, WAPA, TVA) follow federal planning requirements that parallel IRP but are not state-PUC processes.

FERC does not set IRP requirements; state PUCs do. NERC sets resource adequacy standards that any credible IRP must meet. For utilities navigating overlapping state and federal compliance, electric utility compliance software centralizes the evidence and reporting that supports both IRP and parallel filings.

The six components of an integrated resource plan

Every credible IRP, regardless of state, addresses six components. The IRP's analysis layer integrates them into a single least-cost portfolio under multiple future scenarios.

ComponentWhat it answersPrimary data source
Load forecastHow much electricity will customers consume each hour over the planning horizon?CIS billing history, AMI hourly reads, economic forecasts, electrification trajectories
Supply-side resourcesWhich generating units (existing, new, contracted) are available to meet load?Existing fleet data, capacity expansion model outputs, market price forecasts
Demand-side resourcesHow much load can energy efficiency, demand response, and distributed energy reduce or shift?DSM program data, DR enrollment, DER interconnection queue
Transmission and distributionWhat transmission upgrades or distribution investments are required to deliver the planned resources?RTO interconnection studies, GIS asset data, ISO planning models
Fuel and riskWhat are the fuel-price, carbon-price, and policy risks under different futures?EIA forecasts, futures markets, state and federal policy filings
Portfolio integrationWhich combined portfolio meets reliability and policy constraints at lowest expected cost?Production cost model output, capacity expansion model output, stochastic scenarios

The load forecast is the foundation. A 1% error in the 20-year forecast propagates into hundreds of millions of dollars of supply-side decisions. Utilities that historically forecast from monthly billing aggregates now use AMI hourly data to build class-specific load shapes.

How clean is your historical consumption data?

The IRP load forecast is only as credible as the consumption history feeding it. Utilities running on three or four billing systems over fifteen years often have gaps, format breaks, and rate-class definition changes. The forecast modeler ends up reconciling exports from systems no one fully understands anymore. The fix is rarely a forecasting tool. It is a clean, queryable, hourly-class CIS extract the forecast team can trust.

How to build an integrated resource plan

A full IRP cycle from data gathering to PUC filing typically runs 12 to 18 months at an IOU and 6 to 12 months at an electric cooperative. The path is consistent across utility types.

  1. Gather and clean the load history. Extract hourly or monthly consumption by rate class for the last 5 to 10 years. Reconcile billing system changes, rate-class re-mappings, and meter exchanges. This is the slowest step and the most consequential.
  2. Develop the load forecast. Run econometric models, end-use models, or hybrid approaches across multiple scenarios: high growth, low growth, high electrification, high DER adoption. Each scenario produces an hourly load shape for the planning horizon.
  3. Inventory existing supply-side resources. Document every generating unit, contract, and market position, with retirement dates, heat rates, fuel exposure, and operating constraints. Include the planned retirement of any unit reaching end-of-life within the horizon.
  4. Model demand-side and DER potential. Estimate energy efficiency potential, demand response capacity, behind-the-meter solar, electric vehicle load, and battery storage. These resources compete with new generation on a least-cost basis.
  5. Run capacity expansion and production cost models. The capacity expansion model picks the optimal portfolio of new resources. The production cost model dispatches the resulting fleet hour by hour over the horizon to test reliability and economics.
  6. Stress-test the portfolio against scenarios. Run the chosen portfolio through high-fuel-price, low-load, high-carbon-price, and reliability-event scenarios. A resilient portfolio performs reasonably across all scenarios, not optimally in one.
  7. Draft, review, and file the IRP. Compile the narrative, modeling appendices, and rate-impact analysis. Internal review by finance, operations, and legal. Stakeholder consultation. File with the PUC and respond to intervenor data requests.

The IRP cycle rarely runs cleanly the first time. Most utilities iterate steps 4 through 6 as portfolios fail reliability tests or fuel-price scenarios shift. Steps 1 through 3 drive the cost of every iteration. A bad load history makes every iteration partially wrong.

What software supports each IRP step

No single IRP platform covers every step. Most utilities run three to five tools plus their CIS, billing, and AMI systems as data sources.

  • CIS and billing platform. Source of historical consumption by rate class. Must export clean, queryable hourly-class load data.
  • AMI and meter data management. Hourly interval reads aggregated to class-level load shapes. Critical for end-use modeling and DER analysis.
  • Load forecasting tools. Itron MetrixIDR, Itron Forecast Manager, Siemens Spectrum, or in-house models. Produce hourly load shapes by scenario.
  • Capacity expansion models. Energy Exemplar PLEXOS, EnCompass, EPIS AURORA. Pick the least-cost portfolio of new resources.
  • Production cost models. PLEXOS, GE MAPS, PROMOD, ABB GridView. Dispatch the fleet hour by hour to test reliability.
  • DSM and DER tools. EnergyPRO, DNV GL EE Potential, in-house DER adoption models. Quantify demand-side competition.
  • Regulatory submission and document management. SharePoint, Hyland, or specialized regulatory platforms for the filing package and intervenor data requests.

The expensive tools are PLEXOS, AURORA, and the production cost models. The under-invested layer is almost always the data foundation. Utilities on legacy billing systems often spend more on consulting hours to clean the load history than on the capacity expansion model itself.

Does your CIS export hourly load by class?

Many CIS platforms cannot natively export hourly consumption by rate class with stable definitions across multi-year history. Forecasters end up requesting custom extracts as one-off SQL queries that break when the CIS is upgraded. A modern cloud CIS that treats hourly-class export as a first-class API removes a recurring planning bottleneck. Utilities evaluating CIS or billing platforms for IRP support should look at the electric utility billing platform comparison and ask each vendor to demonstrate the hourly-class export.

How CIS and billing data feeds the IRP

The connection between billing and IRP feels distant: billing is monthly, IRP is decadal. The connection is structural. Every hour of historical consumption informing the load forecast comes from the same database that produced last month's bills. The fidelity of that database, the stability of its rate-class definitions, and the accessibility of its hourly export determine the quality of the IRP forecast.

Three concrete linkages:

  • Class definitions. The IRP forecasts load by rate class. Class definitions that drift over time, from billing migrations or new rate options blurring old boundaries, make multi-year trending unreliable.
  • AMI hourly reads. IRP load forecasting depends on hourly load shapes by class, derived from AMI reads through the MDM. If AMI sits in a separate silo from the CIS, the analyst joins them manually every cycle.
  • Adjustments and rebilling. Adjustments, rebills, and write-offs distort raw billed-kWh history. IRP forecasts need delivered-kWh, not billed-kWh. A CIS that exports both views saves weeks of reconciliation.

Emerging IRP requirements

State PUC requirements for IRP content are expanding:

  • Clean-energy targets. Renewable portfolio standards, clean energy standards, and net-zero commitments are now baseline IRP constraints. The IRP must demonstrate a path to compliance, not a hand-wave.
  • DER and grid-edge resources. Distributed solar, behind-the-meter storage, EV load, and vehicle-to-grid are first-class inputs. AMI data is the only credible source for measuring current DER footprint.
  • Equity and environmental justice. Several state PUCs require IRPs to address rate impacts on low-income and underserved customers with explicit affordability metrics.
  • Climate resilience. Wildfire risk, extreme heat events, and storm hardening are increasingly required as IRP scenarios.

The traditional IRP focused on least-cost generation expansion. The modern IRP tests portfolios against reliability, affordability, decarbonization, and equity. For a broader view, the electric utility industry trends overview covers the policy and technology forces shaping the next IRP cycle.

How SMART360 supports IRP-grade data foundations

SMART360 is not an IRP modeling tool. PLEXOS, AURORA, and the production cost models occupy that layer. SMART360 sits beneath, as the CIS, billing, and AMI foundation that produces the consumption history those IRP models depend on. Hourly-class export is a first-class API. Rate-class definitions are versioned. AMI reads flow into the same data model as billed consumption, so the forecast team can compare delivered-kWh and billed-kWh without manual joins.

Island Water Authority deployed SMART360 in 10 weeks and achieved a 47% operational cost reduction and a 92% reduction in billing errors. The foundation that makes those numbers possible is the same one that makes IRP-grade load forecasting possible. Utilities planning a CIS or billing modernization that will feed downstream planning should also look at the ERP integration automation guide.

Frequently Asked Questions

What is integrated resource planning for electric utilities?

Integrated resource planning is a long-range planning document, typically 15 to 30 years forward, that electric utilities submit to state public utility commissions every two to five years. It combines load forecast, supply-side resources, demand-side resources, transmission, and rate impact into a single least-cost portfolio under multiple future scenarios. The IRP shapes capital allocation, rate cases, and generation decisions for the next two decades.

Which electric utilities are required to file an IRP?

Investor-owned electric utilities are required by state law in most states every two to five years. Electric cooperatives taking wholesale power from a G&T cooperative often have their obligations met at the G&T level. Distribution cooperatives that self-supply file their own. Municipal electric utilities generally are not required by state PUCs but often file voluntarily or under federal power supplier requirements.

What software is used for integrated resource planning?

Most utilities run three to five tools across the cycle. Load forecasting commonly uses Itron MetrixIDR, Itron Forecast Manager, or Siemens Spectrum. Capacity expansion modeling commonly uses Energy Exemplar PLEXOS, EnCompass, or EPIS AURORA. Production cost modeling commonly uses PLEXOS, GE MAPS, PROMOD, or ABB GridView. CIS, billing, and AMI platforms supply the historical consumption data.

How long does it take to complete an IRP cycle?

A full IRP cycle from data gathering to PUC filing typically runs 12 to 18 months at an IOU and 6 to 12 months at an electric cooperative. Data gathering and forecasting account for 4 to 8 months. Capacity expansion and production cost modeling iterate over 3 to 6 months. Drafting, review, stakeholder consultation, and filing take 2 to 4 months.

Why does CIS data quality matter for IRP?

The IRP load forecast is built from historical hourly consumption by rate class. CIS data quality determines whether that history is reliable. Utilities running on multiple billing systems often have gaps, format breaks, and rate-class re-mappings that distort trending. A modern CIS that exports hourly-class load data through a stable API removes the recurring data-cleaning burden.

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