Trinity Substation

The proposed Trinity Substation and associated peaking facility will provide reliable generation capacity needed by CORE and the surrounding Douglas County communities. More specifically, the peaking facility will provide a source of dispatchable power CORE can call on when base renewable generation is not available. The peaking facility will also help CORE meet peak demand needs and provide a local, reliable power source for CORE members during periods of high demand. The peaking facility will help balance load on the power system grid by producing energy when demands are high, reducing the load on congested transmission systems and deferring expensive upgrades such as additional transmission lines to meet systemwide peak loads.

The peaking facility will be available for rapid start to power the local grid in times of high local electricity demand, power line interruptions, or both. Unlike intermittent resources, weather conditions, including normal winter weather, will not curtail operation of the peaking facility. CORE expects the facility will run less than 20% of annual hours. This new substation is needed because CORE’s next closest substation, Bayou, does not have sufficient room to expand to accommodate the equipment necessary to handle the energy generated by the peaking facility. Trinity Substation will be able to handle future load growth, as well as the load currently served by the existing Bayou Substation, which will eventually be decommissioned and converted to an underground distribution switching yard.

CORE evaluated several potential sites for the new substation and associated peaking facility. The selected site — the eastern half of an existing 34.55-acre parcel in Franktown, owned by Trinity Lutheran Church and zoned for large rural residential (LRR) — was the strongest candidate across nearly all siting criteria. It offers direct access to current transmission lines, adequate acreage, proximity to natural gas infrastructure, minimal environmental constraints, suitable zoning, strong utility availability, reasons access and site development pathways, and a willing seller.

Construction of Trinity Substation and the peaking facility is planned to begin in XXXX 2026 and be completed by XXXX 2026.

The proposed site is within a 34.55-acre parcel currently owned by Trinity Lutheran Church and zoned for large rural residential (LLR). A replat of the parcel will keep 19.76 acres under Trinity Lutheran Church’s ownership and give CORE ownership of the other 14.79 acres, on which the new substation and peaking facility will be located.

The substation and its yard will have a footprint of approximately 265 feet by 375 feet. The peaking facility will be approximately 440 feet by 640 feet.

The project’s design will leverage the selected site’s natural topography as a buffer. Additional visual screening of the substation and peaking facility will include a 10-foot-high wooden fence along the western side of the site and a row of 26 ponderosa pine trees, each between 15 and 20 feet in height. The trees will be planted on property owned by the Trinity Lutheran Church, on the west side of CORE’s existing overhead transmission line. In addition, a 7-foot chain-link fence with 1 foot of barbed wire on top will encompass the substation and the peaking facility equipment. The chain-link fence will be installed with tan vinyl slats to provide 75% screening.

The peaking facility will consist of a series of containerized linear generators and pad-mounted inverters similar in appearance to a utility-scale battery energy storage facility. It does not require tall stacks or other equipment that exceed the height of a typical one-story residence.

Outdoor lights within the substation will only be used as necessary for emergency and routine maintenance critical for worker safety. All lighting will be cast downward toward the interior of the substation yard. In the power generation area, the lights will be equipped with specified zero uplight, and on motion sensors, so as to operate only when there is work or occupants in proximity.

Trinity Substation will not generate fumes, odors or particulates. Substations emit low-frequency EMF radiation, which is non-ionizing. EMF levels decrease rapidly as it gets further from the source, mainly the transformers, and normally you will find that the EMF outside of a substation is no greater than what is inside a typical residence. Modern substations are also designed to emit lower levels of EMF and follow strict safety standards.

The peaking facility’s linear generators, when operating, implement a unique control system that monitors and adjusts the reaction of fuel and air to significantly reduce the small amounts of nitrous oxide (NOx) they emit. Each generator is also equipped with generating cores that use oxidation catalysts to reduce carbon monoxide emissions.

Air dispersion modeling of emissions from the site has been performed and reviewed by the Colorado Department of Public Health and Environment (CDPHE), which has agreed the impacts on air quality will comply with applicable ambient air quality standards.

Additional resources

• National Institute of Environmental Health Sciences | Electric & Magnetic Fields
• World Health Organization | Radiation: Electromagnetic fields

CORE anticipates just 20 vehicles will enter and exit the project site daily during the nine-month construction period, with an eight-week period in which additional workers and trucks will visit the site.

During normal operations, just two full-time workers will access the site daily. Supplies will be delivered via truck several times per week, and propane will be delivered only a few times per year.