The 10 kW / 120% rule, worked through
Any home can install up to 10 kW DC. Above that, the system’s annual output can’t exceed 120% of what the home used over the previous 12 months, and applications over the limit are sent back to be resized. If the house has less than a year of history, the Town averages what’s available (at least four months); new construction starts at the default 10 kW cap.
Expanding an existing array uses a formula: the Town adds your self-consumed solar to what you drew from the grid to find total use, multiplies by 120%, and subtracts what your current array already produces. Contact the utility before designing an expansion — they’ll need 12 months of production data.
Buying an EV? Tell the utility
If you bought an EV less than four months ago, the Town will add 3,000 kWh to your consumption history for sizing — with proof of purchase and registration at the service address. After four months, the car’s load is already in your history. It’s one of the few Colorado utilities that spells this out.
Batteries and backup
Adding a battery to existing solar requires a new interconnection agreement with updated plans before it’s installed. A standalone backup battery — no solar — still requires a Back-Up Energy Notification with system drawings before installation. Meter collar adapters are accepted only if they’re on the Town’s approved list.
Permits and licensing
Inside town limits, the building permit comes from the Estes Park Building Division, electrical permits and inspections come from the State, and the contractor needs a Town business license. Outside town limits, the permit comes from Larimer County, and ground mounts in unincorporated Larimer County need zoning approval. The system stays off until the Town signs Exhibit B of the agreement, which serves as permission to operate.
Why your fixed charge matters here
Estes Park puts most of the distribution system’s fixed costs into the monthly customer charge, because many customers are part-year residents or net-metered. Solar can offset the energy portion of your bill, but not the customer charge — so payback depends heavily on how many kWh you actually use year-round.
Rebates & programs
Programs change often. Status shown is what we could confirm on the date listed — always check with the program before you count on it.
Efficiency Works
OpenEstes Park Power customers can get an energy advisor, a home energy audit and efficiency rebates through Efficiency Works; the Town recommends it before sizing solar.
- Estes Park Power and Communications customers are served by Efficiency Works.(source)
FAQ
Questions we hear
How big a solar system can I install in Estes Park?
Up to 10 kW DC for a home, or larger if its output stays within 120% of your last 12 months’ use.
Does a new EV let me install more solar in Estes Park?
Yes. If you bought it less than four months ago, the Town adds 3,000 kWh to your consumption history, with proof of purchase and registration at the address.
Do I need permission for a backup battery without solar in Estes Park?
Yes. Submit a Back-Up Energy Notification form with system drawings before installing.
I bought an Estes Park home that already has solar. What do I need to do?
Submit an Interconnection Agreement for Subsequent Owners within 15 days of taking over the account, or the utility may lock out the system.
Is solar worth it for a second home in Estes Park?
Often less than for a full-time home. Most fixed costs are in the monthly customer charge, which solar doesn’t reduce, and part-year occupancy limits how much usage you offset.