Generation Interconnections
If you use solar, wind, biomass, new hydropower, recycled energy or hydrogen fuel cells and your generation capacity is less than 10 kilowatts for your home, or 25 kilowatts for your commercial or industrial business, your generation system may be eligible for CORE’s net metering. Larger systems may also be eligible to interconnect as Qualifying Facilities and be subject to reimbursement from CORE for power generated to the electric grid. Applications for interconnection and system requirements are set forth in the following documents:
Net-metered only
Refer to Level 1 requirements in our Small Generation Interconnection Procedures and Small Generation Interconnection Guidelines.
Qualifying facilities 25 kW or less
Refer to Level 1 requirements in our Small Generation Interconnection Procedures and Small Generation Interconnection Guidelines.
Qualifying systems less than 5 megawatts
Refer to Level 2 requirements in our Small Generation Interconnection Procedures and Small Generation Interconnection Guidelines.
Qualifying facilities larger than 5 megawatts and less than 10 megawatts
Refer to Level 3 requirements in our Small Generation Interconnection Procedures and Small Generation Interconnection Guidelines.
Qualifying facilities larger than 10 megawatts
Refer to the requirements in our Large Generation Interconnection Procedures.
Generators and energy storage for back-up power
Net Metering FAQs
How does net metering work?
The energy your interconnected renewable system generates directly offsets energy that CORE provides you on a kilowatt-hour-to-kilowatt-hour basis. If your system generates more energy than you consume, it is delivered to CORE’s distribution system. If, during a monthly billing period, the energy delivered to CORE exceeds the amount of energy delivered to you from CORE, that energy is credited and carried forward to offset use in future months. An annual “true-up” is performed each year within 60 days of the end of the April billing cycle, at which point CORE provides a bill credit or refund for any remaining excess generation accrued at CORE’s avoided cost of power, as calculated by CORE for the previous calendar year.
What are distributed generation (DG) resources?
DG systems are small-scale, on-site power generating sources located at or near members’ homes or businesses. Some common examples include rooftop solar panels, micro-turbines, small wind and combined heat and power systems. Members with these types of generation systems connect to the local electric grid and use the grid both to buy power from CORE during times when their DG systems are not producing enough to meet their needs and to sell power to CORE when their systems are producing more electricity than is needed.
What is meant by net metering?
Net metering is a billing function that allows members with DG resources to offset their energy usage by their DG output and effectively “sell” any excess electricity generated by their DG systems back to CORE at the retail rate.
What costs are included in CORE’s current net-metering energy rate?
The energy your interconnected renewable system generates directly offsets energy that CORE provides you on a kilowatt-hour-to-kilowatt-hour basis. If your system generates more energy than you consume, it is delivered to CORE’s distribution system. If, during a monthly billing period, the energy delivered to CORE exceeds the amount of energy delivered to you from CORE, that energy is credited and carried forward to offset use in future months. An annual “true-up” is performed each year within 60 days of the end of the April billing cycle, at which point CORE provides a bill credit or refund for any remaining excess generation accrued at CORE’s avoided cost of power, as calculated by CORE for the previous calendar year.
What is meant by avoided cost?
The avoided cost of energy in this context refers to the cost associated with fuel, purchased energy, generated and purchased capacity, and line losses (expressed as a per-kilowatt-hour cost) CORE can avoid by purchasing the energy from a net-metered member. CORE’s avoided cost from May 2023 through April 2024 was $0.05556/kWh per kilowatt-hour. Our avoided cost starting in May 2024 is $0.03778 cents per kilowatt-hour.
For more information on net metering, call (303) 688-3100. If you want more information on renewable energy, consider purchasing Renewable Energy Credits.
Why does the avoided cost change each year?
In previous years, behind-the-meter solar primarily offset purchases CORE would otherwise have made from Xcel Energy, our wholesale power provider. In recent years, however, the growth of solar generation on CORE’s system both utility-scale and distributed means energy that would have otherwise been generated from the Comanche Unit 3 coal-fired power plant (of which CORE is a 25% owner) is mostly offset. Typically, the price of this offset generation is lower than what we pay to purchase energy from Xcel. In addition, to the extent solar reduces wholesale demand charges under our power purchase agreement with Xcel, those savings are included in the avoided cost calculation. These demand charges are based on CORE’s load during the highest single hour of load during the month. Solar generation will typically only contribute to that peak hour during late spring and summer months.
The annual true-up rate is determined based on the prior calendar year’s actual avoided costs for each hour. We don’t receive all information necessary to complete this calculation until mid- or late March, which dictates timing for the true-up.
The higher avoided costs for 2021 and 2022 were due to specific circumstances:
- In 2021, Xcel Energy incurred significant expense to procure natural gas during Winter Storm Uri – approximately $8 million which was passed through to CORE, resulting in a significantly higher than average cost of energy under the Xcel contract for all energy purchased during the month of February 2021. This single event increased the avoided cost for the year by about 11%.
- In 2022, Comanche Unit 3 experienced an extended outage for much of the first half of the year. During this period, all energy produced by local solar generators offset energy purchases under the Xcel power purchase agreement. Historically, the energy price for Xcel purchases is two to 2.5 times the avoidable cost of energy generated from CORE’s share of Comanche Unit 3. In 2022, however, natural gas prices were elevated in the U.S. and throughout the globe due to the events associated with the Russo-Ukrainian War, resulting in energy prices from Xcel that were closer to 3 times what we would have paid for energy generated at Comanche.
- In 2023, our avoided costs returned to more historically normal levels with Comanche 3 operating throughout the year, lower natural gas prices, and the addition of more utility-scale solar plants.
CORE has used this approach to calculate its avoided cost since 2015. Historically, wholesale purchased energy and generation cost vary monthly, based on generator availability, with no pricing variation based on different times of day. As we transition away from our legacy contract with Xcel Energy, we will see different cost structures and we will update our calculation methodology to reflect changed circumstances.