SUMMIT Energy Solutions

Castle Rock city reference

Solar in Castle Rock, checked against utility math.

A city-level guide for Douglas County homeowners comparing quotes, system size, incentive timing, and CORE Electric Cooperative billing assumptions.

Reference ZIP
80104
Utility
CORE
Focus
Net metering + Solar*Rewards

Castle Rock is a Douglas County community between Denver and Colorado Springs with a population of about 74,000, served by CORE Electric Cooperative. Owner-occupants hold roughly 78.5 percent of its homes, and the median home value is about $577,500 with a median construction year of 2005. A 7 kW south-facing array in Castle Rock is modeled to produce about 1,606 kWh per kW installed, or roughly 11,244 kWh per year. Because CORE is a member-owned cooperative rather than Xcel Energy, its rate and program terms should be confirmed directly with the cooperative.

Local numbers

The Castle Rock baseline

A 7 kW south-facing system in Castle Rock produces about 11,250 kWh/year per NREL PVWatts. Pre-incentive install cost runs $18,900 to $21,000, with cash payback around 10 to 11 years before financing markup.

11,250 kWh/year

Annual production

PVWatts v8, 7 kW south-facing.

~$18,900 to $21,000

Net cash cost

After incentives, before financing.

10 to 11 years

Cash payback

No dealer-fee markup.

15 to 19 years

Financed payback

With typical dealer fees.

Utility context

The bill rules are local.

Most of Castle Rock is served by CORE Electric Cooperative. Net metering, rate trajectory, and program timing differ by utility; the Colorado state hub covers the cross-utility picture.

CORE Douglas County Verified 2026-05-29