CORE Electric Cooperative (IREA) Solar: 1:1 Net Metering, 10 kW Cap and QF Rules

If you are a CORE Electric Cooperative member weighing solar, the headline is good: CORE gives full retail one to one net metering for residential systems up to 10 kW, and you can size up to 200% of your usage. Go above 10 kW and the rules change, because your system becomes a Qualifying Facility credited at the lower avoided-cost rate, roughly $0.04616 per kWh as of May 2026. There is also a three-part residential rate to plan around, including a $1.50 per kW on-peak demand charge during the 4 to 8 PM window. Get those three pieces right and CORE Electric Cooperative solar pencils out well for most Douglas County and Elbert County homes.

CORE Electric Cooperative, formerly known as the Intermountain Rural Electric Association, or IREA, is a member owned co-op serving Parker, Castle Rock and much of Douglas and Elbert counties, along with surrounding areas south and east of the Denver metro. Because it is a cooperative rather than an investor owned utility, its board sets the local rules, fees and credit structure. That means CORE solar follows its own playbook, and the details differ from what a neighbor on Xcel or a different co-op may have experienced.

How CORE Electric Cooperative solar net metering works

Net metering is the billing arrangement that credits you for the solar energy your system sends back to the grid. When your panels produce more than your home is using, the surplus flows out to CORE's lines and your meter records that export. At night or on cloudy days, you pull from the grid as usual. At the end of the billing period you are billed for net consumption, which is what you used minus what you sent back.

For CORE members with a system at or under 10 kW, that export is credited at the full retail rate, a true one to one arrangement. That is the most favorable form of net metering, because every exported kilowatt hour is worth the same as one you would have purchased. If you are new to the concept, our overview of how net metering works walks through the mechanics in detail. The practical takeaway for CORE: as long as you stay at or below 10 kW, your solar credits and your retail charges move dollar for dollar.

The 10 kW cap and the 200% sizing allowance

Two numbers shape how big your system can be in CORE territory, and they interact in an important way:

• The 10 kW threshold for one to one net metering. Residential systems up to 10 kW receive full retail net metering. This is the sweet spot, and it covers the large majority of homes. Most Colorado houses land somewhere between 6 kW and 12 kW, so many homeowners can stay under the cap with a well designed system.
• The 200% of usage allowance. CORE permits sizing up to 200% of your historical consumption, which is more generous than the 120% rule many Colorado utilities use. That headroom is helpful if you are planning to electrify, but it does not override the 10 kW one to one ceiling.

Here is the nuance that trips people up. The 200% sizing allowance and the 10 kW one to one cap are two separate limits. You can design a system up to 200% of your usage, but any portion of a system above 10 kW is treated differently for crediting, as we explain next. For most homes the two limits never collide, because a system that offsets 100% of a typical bill comes in under 10 kW. The collision only happens on larger all electric homes.

Going above 10 kW: the Qualifying Facility and avoided cost

If your system exceeds 10 kW, CORE classifies it as a Qualifying Facility, or QF, and the economics shift. Instead of full retail one to one credit, exported energy from a QF is credited at CORE's avoided-cost rate, which was approximately $0.04616 per kWh as of May 2026. That is a small fraction of the retail rate, so every kilowatt hour you export above the threshold is worth far less than one you consume on site.

What this means in plain terms: a 14 kW system does not earn you 40% more value than a 10 kW system. The energy you use in real time still offsets retail charges, but the surplus you push back to the grid from that larger system is paid at the low avoided-cost rate. For most CORE members, the smart move is to size at or near 10 kW and maximize self consumption rather than oversizing into avoided-cost territory.

Avoided-cost crediting is common across Colorado co-ops once you exceed the net metering cap. For comparison, members in southwest Colorado run into a similar structure with La Plata Electric Association, which trues up excess at avoided cost. Because these rates are set by the co-op and updated periodically, treat the $0.04616 figure as current guidance and confirm the rate that applies to your project directly with CORE before you finalize a design.

The three-part rate and the 4 to 8 PM demand charge

CORE places residential members on a three-part rate, which means your bill has more than just an energy charge. The component that matters most for solar is a demand charge of $1.50 per kW applied to your on-peak demand during the 4 to 8 PM window.

A demand charge is based on your single highest spike of usage during the peak window, measured in kilowatts, not on the total energy you consume. Solar alone does not erase it, because by late afternoon and early evening your panels are tapering off right as the 4 to 8 PM window begins. If you cook, run the AC and charge an EV all at once at 6 PM, you can set a high demand peak even on a sunny day. If demand charges are new to you, our explainer on how demand charges work breaks down the concept that increasingly applies to residential co-op members too.

Why a battery changes the CORE math

Because the demand charge lands in the 4 to 8 PM window and CORE credits surplus solar at the low avoided-cost rate, battery storage is an especially strong companion in CORE territory. A battery lets you store midday production and discharge it during the 4 to 8 PM peak, which does two things at once: it shaves your demand spike and it keeps your solar energy on site at full retail value rather than exporting it for pennies. We cover the fundamentals in our home battery storage guide, and we walk through the dollars and cents of discharging into expensive peak windows in our piece on time of use arbitrage with batteries.

For an all electric CORE home with an EV, the combination of a right sized solar array near the 10 kW threshold plus a battery often beats a single oversized array that pushes surplus into avoided-cost crediting. The battery captures value the larger array would give away.

Why work with ProGreen Solar in CORE territory

ProGreen Solar is a Colorado company serving the Front Range and the Western Slope. We are a licensed electrical contractor, EC.0101788, NABCEP certified, with an A plus rating from the BBB. With a co-op like CORE Electric Cooperative, the difference between a smooth project and a stalled one usually comes down to knowing the local rules: the 10 kW one to one cap, the Qualifying Facility avoided-cost trigger, the 200% sizing allowance and the 4 to 8 PM demand charge. We design to those specifics rather than a generic template, and we model whether a battery improves your particular bill before you spend a dollar.

Getting started

Solar with CORE Electric Cooperative is a strong fit once you account for the 10 kW one to one cap, the avoided-cost rules above that threshold, the 200% sizing allowance and the 4 to 8 PM demand charge. The smartest first step is a usage review so we can size your system to your home, confirm the current CORE rate terms together, and show you whether storage makes sense for your peak. When you are ready, visit our residential solar page or reach out for a no pressure assessment of your Parker, Castle Rock or Douglas County home.

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