The Energy Cooperative (TEC) recognizes that Members may be interested in purchasing and operating small renewable powered generating systems to provide electricity to their home or business. However, there are formal rules for interconnections between small customer-owned generators and electric utility providers. TEC’s primary concern is that these systems be interconnected safely in accordance with all applicable codes and regulations, without adversely affecting TEC’s electrical utility system. Interconnection requirements for systems up to 25 kW are covered by the Technical Requirements for PURPA Interconnections are available online by clicking here or by calling 800-255-6815, extension 1294.
Renewable generation (RG) systems include wind turbine generators, solar photovoltaic panels, biomass from animal waste, fuel cell, or other qualifying renewable energy generating systems as defined by PURPA.
Wind systems utilize a wind turbine collects kinetic energy from the wind, and converts it to electricity that is compatible with a home’s electrical system. Wind Map
A photovoltaic (PV) system uses solar cells to convert light into electricity. The electricity generated by a multitude of these cells can be channeled into an inverter for conversion into a usable power source that is compatible with a home’s electrical system. Solar Guide or Solar Water Heating Guide
For small RG systems, the member will be credited for the power that is generated back to the grid by a “net metering” process. The meter on the facility is changed to an electronic meter that records the power the member draws off the grid and the amount of power the member generates back on to the grid. The two readings are used to determine the billing.
The Cooperative shall bill the Member for the excess of energy supplied by the Cooperative over and above the energy supplied by the Member during each billing period according to the Cooperative’s applicable retail rate schedule. When the energy supplied by the Member exceeds the energy supplied by the Cooperative during a billing period, the monthly charge and/or minimum bill of the retail rate schedule shall be billed by the Cooperative. If the energy place on to the grid is greater than the amount drawn from the grid, the excess energy shall be credited at an avoided cost rate.
TEC requires that the following procedures be followed for interconnection of RG generating systems:
Application for Interconnection*
As part of the application, a plan must be submitted by TEC that contains the electric design, interconnection requirements, capacity of the system and operating characteristics. This is to review the interconnection requirements.Generators that are interconnected with the electric grid can possibly energize TEC electric equipment during an outage. To prevent this from occurring, the RG system shall be complaint with IEEE Std. 1547. The Member is required to install a utility interactive grid-tied inverter system that is UL 1741 certified and IEEE Std 1547 compliant. Attach a copy of the Certificate of Compliance from UL, Underwriters Laboratories, Inc and a statement of compliance with IEEE Std 157 from the manufacturer, to the application.Approval from TEC for parallel operation with TEC electric distribution system must be obtained prior to operation to assure that the RG system will not adversely affect the safety, reliability, or quality of local electric service.
*Facilities less than 25 kW of capacity shall not be required to provide additional liability insurance coverage.
Cooperative Agreement for Interconnection and Parallel Operation of Distributed Generation*
After the application has been approved, the Member will send the Member two original copies of the Agreement for Electric Service for Net Metering and Interconnection and Parallel Operation Agreement for up to 25 kW QFs for signature, and submit payment for facilities charges if required.
Inspection of facilities prior to interconnection
After construction of the RG system is complete, and after it has received the final electrical inspection from the local building codes authority, the Member will need to contact TEC for an interconnection approval inspection. The purpose of TEC’s inspection will be:
• To verify that the facility has been constructed as it is represented in the application and in the Interconnection Agreement.
• To verify the RG system isolation device is in compliance with TEC’s requirements.
• To install permanent warning signs on the meter enclosure and utility disconnect switch.
.• Installation of the Net Meter.
After the interconnection has passed TEC’s inspection and all requirements have been satisfied, TEC will provide written authorization for the Member to commence interconnected operations. TEC will return one of the fully executed Agreement for Electric Service for Net Metering and Interconnection and Parallel Operation Agreement for up to 25 kW QFs forms to the Member. Operation of the wind or photovoltaic generation system will be subject to compliance with TEC policies and procedures located in the Technical Requirements for PURPA Interconnections
*The “Application for Interconnection” form, Agreement for Electric Service for Net Metering and Interconnection and Parallel Operation Agreement for up to 25 kW QFs contracts are also available at our Energy Cooperative Office locations.
• The Member must meet all the Cooperative’s membership and service requirements in addition to the requirements in the Technical Requirements for PURPA Interconnections.
• It is the Member’s responsibility to ensure that the RG system complies with all applicable city, state, and federal codes, laws, and regulations, and to obtain all necessary permits.
• The Member shall pay in advance, prior to installation of the RG system, the full cost of the construction of any utility facilities, or other operation and maintenance expense which, at the sole discretion of the Cooperation and/or its power supplier, is required to serve the Member’s facility.
• RG systems such as Wind and PV systems must automatically disconnect from TEC’s system when there is a TEC power outage. During a power outage, a RG system has the ability to back-feed TEC’s power line, creating a hazardous condition. To prevent this from occurring, the RG system shall be complaint with IEEE Std. 1547.
• Installation of a visible break disconnect switch is required at the Member’s expense. The switch must be lockable and located within three (3) feet from the Cooperative’s meter, and be properly labeled as “Utility Disconnect Switch”. TEC shall have the right to lock the switch in the open position if it is necessary to maintain safe electrical and/or maintenance conditions that adversely affect the cooperative system, or if there is a system emergency or other abnormal operating condition warranting disconnection.
• To avoid unnecessary cost and delay, it is recommended that TEC’s approval of the final interconnection design be obtained prior to purchasing material or equipment for the project.
As determined at the sole discretion of the Cooperative on a non-discriminatory case-by-case basis to recover any additional operation and maintenance expense caused by the interconnection of the RG facility.
Questions to Ask Before Investing in Small Wind:
Interested in buying a wind turbine? Make sure to ask these questions first:
- How reliable is the rated energy output? How did you calculate the output? What wind speeds did you use?
Experts advise ignoring peak output and power curves provided by vendors. Rather, look for the monthly or annual energy output – in kilowatt-hours – for the turbine, estimated for the average wind speed that you expect or have measured at your site.
- Is the inverter UL listed?
If the inverter (required to convert direct current power from the turbine to alternating current power of the grid) is not Underwriters Laboratories, Inc. (UL), listed, find another vendor. Most electric co-ops require that an inverter carry a UL 1741 certification for interconnection with the grid.
- What is the estimated total installed cost? What does the turbine cost? What does the tower cost? How much is installation estimated to cost? How much will interconnection cost?
Budget for labor expenses as well as the cost of equipment rental, concrete and rebar, electrical components, shipping and sales tax. It adds up fast.
How long is the warranty? What does it cover – parts? Labor? Can it be extended? If so, what will it cost? How much maintenance will be required and what will it cost?
What periodic maintenance is required and the cost?
Warranties range from one to five years. The longer the warranty, the better. Make sure the warranty covers labor as well as parts. Ask owners of wind systems purchased from the same vendor about performance and reliability before making a decision on an extended warranty, if available. If you live in an area prone to lightning strikes, you should strongly consider the option of lightning protection.
How long has the vendor been in business? How many turbines have they sold? Have their turbines been certified? Can they perform maintenance, or is there another licensed repair technician in the area?
Look for vendors that have been in business for at least five years or have acquired the product line of another vendor. In addition, ask the vendor for the names of at least two people who have installed a similar model wind turbine. Check with the references to ensure they are happy. Ask them if there was anything they wish they had known before investing in a turbine.
The Small Wind Certification Council has been conducting a small wind certification process in the U.S. (www.smallwindcertification.org). Small wind turbines can be certified using the International Electrotechnical Commission (IEC) standard, IEC 61400-2, for testing wind turbine power performance. This standard is increasingly used by U.S. manufacturers.
What are your electric co-op’s interconnection policies? What will the co-op pay for any excess energy you may produce?
Electric cooperatives must provide all of their members with safe, reliable, affordable electric service. Most co-ops have interconnection policies designed to permit interested members to own their own generation without impacting the quality or cost of service received by other members. Knowing what those policies are before purchasing a wind turbine will help you better evaluate the full cost and benefits of the investment.
What local zoning laws, electrical codes, homeowners’ association requirements or other local laws and standards apply to wind turbines?
Some local zoning ordinances and homeowners’ association policies restrict the height of wind turbines or require that they be set back a specified distance from the property line. Those restrictions may prevent you from taking advantage of the best wind resources or may require extra time to pursue a waiver or exception. Local electrical or building codes may also impose additional time or expense.