CORE’s Energy Transformation

The path to a new energy future

Since 1938, CORE’s power supply has continuously adapted to meet the needs of our ever-growing membership. CORE is committed to a clean energy transformation through the development of a diverse portfolio of renewable energy sources, battery storage technology and thermal generation backup.

In response to state and local legislative requirements, CORE submitted a Clean Energy Plan to the Colorado Department of Public Health and Environment in late 2023. The plan outlined our path to an 80% reduction in greenhouse gas emissions by 2030, from a 2005 baseline, in line with House Bill 19-1261. Additionally, CORE retires Renewable Energy Credits equal to 20% of our retail sales each year to comply with the Colorado Renewable Energy Standard.

Since filing the Clean Energy Plan, changes to the energy landscape and market require CORE to adjust timing and near‑term expectations. Although CORE secured contracts for new wind and solar projects early in the process, the transmission system needed to deliver that energy has become increasingly constrained. Along with recent changes in federal renewable tax incentives, those projects are no longer financially workable.

Despite these challenges, progress continues. CORE has added 75 MW of solar and 100 MW of battery storage that connect directly to our system. These projects help us move forward, but local renewable potential is limited, and large‑scale wind additions require transmission access currently outside CORE’s control.

While the timelines may look different, CORE remains committed to reducing greenhouse gas emissions while providing reliable, affordable service to members. We will continue advocating for improved transmission access, regional market solutions and balanced energy strategies.

View CORE's Clean Energy Plan

View CORE's Clean Energy Plan Update

Wind

Future wind projects will harness this abundant Colorado resource.

Solar

Current and future solar facilities, along with members’ rooftop solar panels, power the grid.

Hydro

Learn more about our Western Area Power Administration (WAPA) hydropower resources.

Comanche Coal Plant

Comanche Unit 3 will continue to supply energy and capacity through its planned closure.

Grid-scale battery energy storage. A large battery energy storage system (BESS) in a desert environment, likely used to store energy from renewable sources like solar power.

Battery Storage

Battery storage plays a key role in maintaining a reliable grid.

Natural Gas

Future natural gas backup resources will ensure reliability.

Comanche Unit 3 coal plant

CORE opted to purchase a minority share of 25.33% in the coal plant proposed by Public Service Company of Colorado (PSCo) in 2006. Another Colorado cooperative, Holy Cross Energy, purchased a matching minority share. PSCo is the majority owner and serves as operator for the plant. The plant began operation in 2010 and entitles CORE to approximately 190 of the generator’s 750 megawatts. Historically, Comanche Unit 3 supplied CORE with 1,150,000 megawatt-hours of energy each year between 2011 and 2023. PSCo has proposed early closure of the plant, currently expected to be no later than Jan. 1, 2031. The Colorado Public Utilities Commission, which regulates PSCO’s resource planning, has approved this early closure and a gradual reduction in generation at the plant between 2025 and 2030. CORE expects to continue to use energy and capacity from Comanche Unit 3 to meet its members’ electrical needs through its closure.

Arapahoe Combined Cycle Natural Gas Plant

CORE will purchase energy and capacity from the Arapahoe Combined Cycle Plant beginning in 2026. This 120-megawatt plant was built in 2000 and consists of two gas turbines: a heat recovery steam generator and a steam turbine. After the plant’s existing power purchase agreement expires in 2025, CORE will use it to meet its members’ energy needs. The plant has historically met or exceeded its reliability targets and will support deliveries from weather-dependent resources like wind and solar. Over time, CORE expects to dispatch this plant less as more of CORE’s contracted renewable plants begin operation.

Spindle Hill Combustion Turbine Plant

The Spindle Hill combustion turbine project, operated by a subsidiary of Invenergy, is a 300-megawatt natural gas peaking plant that began operation in 2007. CORE will dispatch the plant to meet peak load needs and support renewables beginning in Spring 2027, after its existing power purchase agreement expires.

Victory Solar

CORE entered into a power purchase agreement on a 12.8-megawatt solar facility, Victory Solar, that went online in late 2015. The plant is located north of Bennett, in Adams County, and includes nearly 48,000 panels that follow with the sun each day on a single-axis tracking system to maximize energy production of about 28,000 megawatt-hours each year.

Pioneer Solar

Pioneer Solar, CORE’s second utility-scale solar facility, began operation in late 2020 near Bennett, in Adams County, with a rated capacity of 80-megawatts across two large parcels. It uses a single-axis tracking system that allows its 340,000 photovoltaic modules to follow the sun each day and maximize energy production and generate nearly 200,000 megawatt-hours annually.

Hunter Solar

CORE’s third utility-scale solar facility began operation in late 2023. Hunter Solar is in Arapahoe County, south of Bennett, and is rated to produce a peak output of 75 megawatts. CORE purchases 60% of Hunter’s output under a long-term contract; Hunter sells the other 40% to another Colorado cooperative, Holy Cross Energy. The facility’s 220,000 solar panels are expected to produce about 180,000 megawatt-hours each year – about 110,000 of which CORE expects to purchase.

Distributed Generation

CORE’s members are also active participants in the power supply transition. As of August 2024, 9,600-plus members have installed nearly 60 megawatts of renewable generation at their homes and businesses. This generation is mostly solar panels, with a slowly increasing share paired with batteries. In 2024, CORE has energized an average of 580 additional kilowatts of renewable distributed generation each month.

CORE’s Energy Transformation

The path to a new energy future

Wind

Solar

Hydro

Comanche Coal Plant

Battery Storage

Natural Gas

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