Distributed generation (DG) is the generation of electric power from a small energy source and is an alternative to the large scale traditional electric power generating plants. The use of a wind turbine or solar panels to generate energy on site at the member’s premises is an example of DG. Members generally use this energy to meet their electric power needs, but excess power may be sold back to Medina EC at the avoided cost rate. Members who do sell back excess power will see it on their bill as a Distributed Generation Credit, and the rate per kWh for that month will appear to the side of it. If you have a general question about DG systems, email us at Info@MedinaEC.org.

Distributed Generation Interconnection Process

Members interested in interconnecting DG to Medina EC’s system should:

  • Consult with a qualified DG developer, installer or electrical consultant to determine technical requirements and potential costs.
  • Call 1-866-MEC-ELEC (632-3532) or email us at Info@MedinaEC.org and let us know you are considering a DG system.
  • Read and understand the DG portion of the tariff to ensure that all provisions will be followed. Please make note of the insurance requirements. Medina EC does require the owner of any DG system on our lines to show proof of liability insurance of at least $300,000 per occurrence. This can extend from your homeowner’s policy or be covered under an umbrella policy, depending on what your agent says. The cooperative will accept a declarations page or certificate of insurance stating the amount of coverage.
  • Complete the DG Application and return it to Medina EC with the application fee and a system design document created by an acceptable commercial software.
  • Schedule a time for a Medina EC representative to visit the proposed DG facility.
  • Complete the DG Interconnection Agreement and return it to Medina EC along with any necessary insurance documents.
  • Give Medina EC the opportunity to witness or verify the testing of the DG facility.
  • If system testing is approved and all conditions of the interconnection agreement are satisfied, the DG facility is eligible to operate in parallel with the electric distribution facility of Medina EC.


Medina EC allows the interconnection of DG facilities to the electric distribution system of Medina EC under certain conditions. The DG Tariff of Medina EC currently allows interconnection of DG facilities up to 10 megawatts (MW) in size. The DG Tariff has a complete list of rules regarding interconnection of a DG system to the Medina EC electric distribution system. Systems above 700 kW also require the review and approval of Medina EC's wholesale power provider, South Texas Electric Cooperative.


If a member’s DG system is interconnected with the facilities of Medina EC, the member is required to disclose to Medina EC the presence of the DG system. Non-disclosure of an interconnection of a DG system could result in harm to Medina EC personnel and discontinuance of service to the member. Once Medina EC is made aware of the distributed generation system, we will have to make changes in our metering and billing systems so that the member gets credit for all power produced by their DG system.

Nonrefundable Application Fee


Systems 10 kW or smaller = $0


Systems 11 kW to 50 kW = $250

Systems 51 kW to 1 MW = $700

Over 1MW to 10MW = $1,000


Possible Additional Charges

If an interconnection study is required, the member will be required to compensate Medina EC for the cost of the study.

If system improvements or lines extensions are required, the member will be required to pay the cost of those.

If the system is larger than 700 kW, South Texas Electric Cooperative will also require a separate application and fee for an interconnection study.


Interconnection is a one-time fee. There is a added monthly service charge for systems larger than 1MW.

Installing your own distributed generation facility is an individual decision for each member. Medina EC’s role is to help educate the member regarding Medina EC’s expectations in this process. The member has the responsibility of determining whether the facility will generate enough electricity to offset the cost of equipment and installation. Medina EC will try to help you obtain information you deem relevant to your decision making process. A few things to consider are the overall cost, realistic estimated production, location, AC wattage output of the system, your overall energy use and your goals with the system.

It depends.

If a member generates more electricity than they consume and their system is 700kW or less, they are credited for each kWh pushed back onto the grid at the avoided wholesale power cost, or the cost Medina EC would have incurred had we been required to purchase the energy from a wholesale power supplier. Members will see that on their monthly bill as a Distributed Generation Credit.

The avoided wholesale power cost is calculated by dividing the prior 12 months’ total wholesale power purchase cost (excluding demand costs, transmission costs, ERCOT and related distribution costs) by the 12 months’ total kWh’s purchased.

If your system is larger than 700 kW, the member will need to contact South Texas Electric Cooperative about purchasing excess energy.

Solar by Medina EC is available to current Medina EC members. We will install a 5kW ground mount system for $15,000 + taxes.

Learn more here.


Production of DG systems will vary.

Medina EC has installed several distributed generation systems in hopes that their production numbers help our members make a decision on if similar options are right for them. These renewables produce energy that goes back in to the buildings, to help offset the electric use.

Medina EC General Office Building
5kW ground-mounted PV system
As sold and installed through Solar by Medina EC

Medina EC Engineering Building
30kW roof-mounted photovoltaic array (PV system)

Medina EC Rio Grande City Office
10kW ground-mounted PV system

Medina EC Dilley Office
45-ft, 2.4 kW wind turbine
1.14 kW ground-mounted PV system

Dilley Solar & Wind