Transparent by design

Official Sources and Methodology

Battery Calculator uses utility and program sources to build decision ranges. This page shows the sources behind the first three calculators and the assumptions that still need user-specific data.

Policy status

Last reviewed August 3, 2026

Program rules can change. Check the official source before signing a contract, especially when your result depends on a deadline, income qualification, or VPP enrollment.

Rhode Island Energy Battery Program

Rhode Island Energy

Rhode Island EnergyCurrent sourceBattery Program$225 per average kW performed, $6,875 seasonal cap, event timing and standalone battery rules.Rhode Island Office of Energy ResourcesCurrent sourceConnectedSolutions storage overviewState-level program context and seasonal incentive information.

Historical and superseded sources

Older policy pages stay visible for auditability. They are not automatically used as current calculation rules.

Rhode Island EnergyHistorical reference2024–2026 Battery Energy Storage Program GuideHistorical program guide retained because it contains an illustrative $400/kW example and says the program is subject to regulatory change.Effective from: 2024. Validity: 2026 guide; subject to regulatory change. Checked: 2026-08-03.Retained for version comparison; the current calculator uses the current program page for the published rate.Replaced in this site by: Battery Program

Renewable Battery Connect

Xcel Energy Colorado

Xcel EnergyNeeds reviewRenewable Energy Plans & ReportsCurrent planning and regulatory context; it does not by itself confirm live Renewable Battery Connect enrollment terms.Checked: 2026-08-03.Used to track current program direction while operational enrollment terms remain unconfirmed.Xcel EnergyCurrent sourceColorado residential time-of-use rateCurrent peak-period context for the energy-value estimate.

Historical and superseded sources

Older policy pages stay visible for auditability. They are not automatically used as current calculation rules.

Xcel EnergySupersededRenewable Battery Connect information sheet (2025 reference)Historical reference with the published $500/$800 per-kW figures and equipment limits; the sheet says through 2025 or until funds are exhausted.Validity: Through 2025 or until incentive funds are exhausted. Checked: 2026-08-03.Not used in the current incentive result until Xcel publishes or confirms current enrollment terms.Replaced in this site by: Renewable Energy Plans & Reports

SMUD Home Battery Storage Program

SMUD

SMUDCurrent sourceHome battery storage$500/kWh less 20% holdback, $10,000 household cap, nameplate basis, PTO window and VPP participation.SMUDCurrent sourceSolar and Storage RateExport compensation and rate-plan context.SMUDCurrent sourceSolar and Storage compensation updateRecent compensation update and program context.

How estimates work

What the first version includes

Program incentives and published participation payments.
An estimated battery energy value shown as a conservative-to-optimistic range.
Net cost after the modeled incentive and a maximum quote for a 10-year payback.
Warnings when an input or program condition can materially reduce the result.

Backup power value is not assigned a guaranteed dollar amount. Actual savings depend on your load shape, rate plan, battery dispatch, outage needs, installer quote, financing, and future policy changes.