Castle Rock electricity and gas rates
Who supplies power and gas to Castle Rock houses and what a typical house uses: about 863.6 kWh of electricity and 91 therms of gas a month.
Electricity: CORE Electric Cooperative
CORE's 2026 residential rate is a $20.00 basic service charge, $0.1155 per kWh and an on-peak demand charge of $5.47 per kW. In the Colorado Association of Municipal Utilities' July 2026 survey, 700 kWh on CORE's residential rate cost $124.92. CORE's rates list a 3% franchise charge for Castle Rock (2% for services over $10,000).
| Charge | Price |
|---|---|
| Fixed charge | $20.60 a month |
| Per kWh | 15.44¢ |
Gas: Black Hills Energy (Black Hills Colorado Gas)
Black Hills Energy supplies natural gas in Castle Rock (Base Rate Area 3, Eastern GCA region). Residential rate effective October 1, 2026: $12.00 customer charge plus $1.96 of monthly riders, and $0.61614 per therm including the $0.35 gas cost adjustment.
| Charge | Price |
|---|---|
| Fixed charge | $13.96 a month |
| Per therm | 61.61¢ |
Pay or manage it
Sources
- CORE Electric Cooperative rates and regulations (2026)
- CORE Electric Cooperative: rate comparisons
- EIA: 2024 residential electricity sales by utility (Table 6)
- Black Hills Colorado Gas tariff (Colo. PUC No. 1), rates effective October 1, 2026
- Black Hills Colorado Gas: quarterly GCA customer notice (2024), average residential usage
Checked October 21, 2026. Every number here comes from the public sources listed, matched by our checker.
Rates change every year; this page shows when it was last checked. Nothing here is legal, tax or insurance advice.