Ames Electric Department - Net Metering

April 15, 2008


In March 2008 the Ames City Council approved a resolution adopting interconnection procedures and a net metering tariff rider for renewable electricity generators smaller than 10 kW.* The tariff and procedures apply equally to all classes of Ames Electric Department customers. Renewable energy is defined to include technologies that rely exclusively on wind, solar, biomass, biomass waste products, landfill gas, hydroelectric, geothermal, wave, and tidal power. It does not include technologies that rely on fossil fuels, fossil fuel waste products, or waste products from inorganic sources. The use of the word "exclusively" in the definition would apparently disqualify mixed resource systems (e.g., coal-biomass co-firing). Under the terms of the interconnection agreement, systems must be in compliance with all applicable provisions of the National Electric Code (NEC); UL Standards 1741 and 1703; IEEE 929; and all local building codes. The rules also contain additional technical requirements, including the installation of a utility accessible external, lockable disconnect switch. The utility may have a representatives present at the initial system test, and may perform additional tests at its own expense within 20 days of the receipt of a Certificate of Completion from the customer-generator. The witnessing provision is waived after 20 days. Any renewable energy credits (RECs) or other environmental attributes produced by customer-sited systems accrue to the utility. Metering is accomplished using a single bi-directional meter at the customer's original place of metering to measure net electricity consumption. Net excess generation (NEG) as calculated for any billing month may be carried over to subsequent months as a credit at the customer's retail rate. Credits may only be banked for 12 months, at which time they are granted to the utility. The minimum enrollment term under the net metering rider is one year, extended automatically unless terminated by either party with 60 days written notice. The customer is responsible for all permitting and interconnection costs associated with system installation and operation. *Iowa was one of the first states in the country to adopt statewide net metering rules (1984), but the statewide rules apply only to investor-owned utilities (IOUs). Municipal and cooperative utilities are free to adopt (or not adopt) net metering rules at their own discretion.

Program Overview

Implementing Sector: Utility
Category: Regulatory Policy
State: Iowa
Incentive Type: Net Metering
Web Site:
Start Date:
Eligible Renewable/Other Technologies:
  • Geothermal Electric
  • Solar Thermal Electric
  • Solar Photovoltaics
  • Wind (All)
  • Biomass
  • Landfill Gas
  • Tidal
  • Wave
  • Wind (Small)
  • Hydroelectric (Small)
  • Anaerobic Digestion
Applicable Utilities: 10 kW
System Capacity Limit: None specified
Aggregate Capacity Limit: Carried month to month at retail rate, granted to utility after 12 months
Ownership of Renewable Energy Credits: Yes


Name: Interconnection Agreement and Net Metering Tariff
Date Enacted: 03/25/2008
Name: City Council Resolution 08-109
Date Enacted: 03/25/2008

This information is sourced from DSIRE; the most comprehensive source of information on incentives and policies that support renewables and energy efficiency in the United States. Established in 1995, DSIRE is operated by the N.C. Clean Energy Technology Center at N.C. State University.