Renewable Energy FAQs

What is the difference between DG and a wind farm?

The main difference is that DG is small, customer-owned equipment that provides power to the customer in parallel with OEC’s system. A wind farm is a collection of very big wind generators connected to the transmission system. OEC does not own any transmission line (it only distributes power) and, therefore, is not directly involved in wind farms.

How do I get involved in a wind farm?

Unfortunately, OEC’s service territory is not where power suppliers are currently looking to place wind farms. OEC’s power supplier, Western Farmers Electric Cooperative, owns several wind farms throughout Oklahoma. WFEC, as well as other power suppliers, carefully select wind farm locations based upon a number of factors and only then do they contact landowners in order to get the generators built.

How much does a DG system typically cost?

Both initial capital costs and operations and maintenance costs can vary significantly depending on the project size. A residential DG system designed to supply 100% of one’s power requirements is rarely an economically sound investment.

Are there any tax breaks or incentives for installing renewable DG systems?

OEC does not closely monitor state and federal DG tax policy. However, the Database of State Incentives for Renewable & Efficiency (DSIRE) contains a wealth of information:www.dsireusa.org(link is external).

Will OEC buy power from a DG system?

Yes. OEC buys power in two ways: Net Metering and Power Export. Net Metering is offered for systems 25 kW and smaller. Power Export is offered for systems 25 kW to 3 MW systems. Power Export is where OEC will install a separate meter and buy back power at the wholesale rate.

What is Net Metering?

Net metering allows an electric meter to turn – or, if digital, count – backwards when an on-site generator produces more energy than is being used. For example, if a DG system produces 1,000 kWh and a residence uses 1,800 kWh in a given month, the meter will only show 800 kWh used. Therefore, the bill will be for only 800 kWh. If the DG system produced the full usage of 1800 kWh, OEC will bill only the service availability charge. In short, Net Metering means OEC essentially buys back power at the retail rate as long as the DG system doesn’t produce more power than is used during the billing period.

What happens if I produce more than I use in a month?

Should your DG system generate more electricity than you use during the month, the excess energy simply flows back to the power grid. OEC does not credit your account or reimburse you for the excess generation. Regardless of the DG system’s production, OEC will bill you for the service availability charge.

What about DG systems over 25 kW?

OEC allows interconnection for DG systems up to 3 mW but Net Metering is limited to systems 25 kW or less. For systems over 25 kW, the co-op will install separate facilities to the generator and the power will be delivered directly to our distribution system. The output is metered and OEC pays the owner of the generator for the power output at the wholesale or avoided cost rate (approximately 3.5¢ per kWh). This is called Power Export.

It is important to note that the larger the DG system, the more of an impact it will have on OEC’s distribution system. Consequently, OEC has more requirements for interconnection of DG systems over 25 kW. For more information, please contact OEC’s Engineering Department.

What are OEC’s voltage requirements for Net Metering?

Since OEC’s distribution system and DG systems operate as parallel power sources, the DG system must be the same voltage as OEC’s service. For residential accounts, this is almost always single-phase, 120/240V 60 Hz.

What happens if OEC has a power outage?

If OEC loses power, the DG system should shut down. If the DG system remained in service, it would actually back-feed and energize OEC’s line, a very dangerous and potentially deadly situation for OEC linemen.

What does OEC require of a member who wants to install a DG system of 25 kW or less?

All equipment for DG systems that are Net-Metered are on the member’s side of the meter; therefore, OEC is not directly involved with the installation. OEC does require:

1. Member to submit an application;
2. Member to furnish certification from manufacturer or engineering firm that equipment meets IEEE 1547 and other applicable codes and standards;
3. Member to use an Oklahoma licensed electrician/electrical contractor;
4. Installation of a separate, lockable, OEC-accessible safety disconnect;
5. Execution of a contract between OEC and the member;
6. Final inspection by OEC.

OEC requires the DG system to comply with all applicable laws, ordinances, rules and regulations of any federal, county, state and/or local authority, including, but not limited to: the most recent IEEE Standard 1547 Guide for Distributed Generation Interconnection and applicable ANSI Standards, including ANSI C84.1 Range A, relating to installation, safety, easements, code restrictions, operation and other matters.

Resource Files

OEC’s DG information packet  – includes FAQs, DG Agreement (short form contract) and Application for DG systems of 25kW or less

OEC/WFEC DG Procedures and Guidelines Manual – a procedures and guidelines manual developed by WFEC, OEC’s power supplier, and adopted by OEC.

Additional Resources

American Wind Energy Association – the national trade association for the U.S. wind industry

SolarBuzz – for the latest news, research findings and industry trends

Oklahoma Wind Power Initiative – investigates and promotes wind energy in Oklahoma

U.S. Department of Energy’s Office of Energy Efficiency & Renewable Energy

Database of State Incentives for Renewable & Efficiency (DSIRE) – a comprehensive source of information on incentives and policies that support renewables and energy efficiency in the U.S.

OEC WindWorks Information