RES Historical Rates and Cost Comparison

Historical Rates, System Costs, and Program Data

To assist you in determining if solar is right for you, we recommend comparing multiple estimates from different solar installers and comparing their options, which may include: 

  • Homeowner Purchase – Solar PV systems may be purchased in cash or financed through a loan. Term rates (length of the loan) may range between 10 to 20 years, which may be available at different interest rates. After the payback period, solar owners can see greater benefits from their upfront investment.
  • Solar Lease – With a solar lease, a third-party developer or financing company owns and may, or may not, maintain the solar PV system. Lease terms are typically 20 to 25 years, during which the homeowner pays a series of fixed or escalating payments to the developer. Payments are set ahead of time, so monthly costs are fixed and/or predictable. At the end of the term, the customer can choose to extend the lease, purchase the system at a discount, or have the system removed. 
  • Power Purchase Agreement (PPA) – With a solar PPA, a third-party developer or financing company owns and may, or may not, maintain the solar PV system. PPA terms are typically 20 to 25 years, during which the homeowner purchases the energy produced by the system at a fixed or escalating rate (cost per kilowatt-hour of energy produced). Because a customer's monthly solar costs will vary based on system production, bills are typically higher in the summer and lower in the winter. At the end of the term, the customer can choose to extend the PPA, purchase the system at a discount, or have the system removed.

In addition, you may find it useful to review historic electric rates as well as recent solar installation costs from projects receiving the Residential Renewable Energy Solutions incentives. The tables below provide UI’s recent historic residential electric rates and average installed costs for solar and solar plus energy storage systems installed as part of the Residential Renewable Energy Solutions Program.

For information about the current Incentive Options available for your solar project, visit our Residential Renewable Energy Solar Incentives page.
 

Historical Residential Standard Service Generation and Delivery Rates

View historical rate information in the linked document.

Residential Rates RT & R

UI offers two rates for residential customers: Rate RT and Rate R.

  • Rate R - Summary Non time-of-use.
  • Rate RT - Peak & Off-Peak time-of-use.

Time-of-use rates are charged to UI residential customers taking service under Rate RT.
Peak rates are charged from noon to 8 p.m. on weekdays or about 24% of the total weekly hours.
Off-Peak rates are charged from 8 p.m. to noon on weekdays and all weekend hours, or about 76% of the total weekly hours. Any residential customer can request service under the time-of-use rate.

Historical System Costs-Residential Renewable Energy Solutions Projects

View historical information in the linked document.

Historical Renewable Energy Solutions Program Data

Residential and Non-Residential Renewable Energy Solutions Program Data beginning January 1, 2022 is available in a downloadable format using the links below. For residential projects, these workbooks provide aggregated and averaged system, electricity (kWh) production, tariff and ownership data. For non-residential projects this workbook provides selection status, tariff type with beneficiary name when applicable as well as the bidder, customer, project ownership and location information. Lastly, this workbook contains project specific information including the project's rate class when applicable, technology type and system size followed by the project’s estimated production and value.

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