Connecticut Natural Gas Corporation Rate Selection Guide
Connecticut Natural Gas Corporation (CNG), an AVANGRID local distribution company, serves roughly 215,000 gas customers across Greater Hartford, New Britain, and Greenwich. CNG offers billing portal access, an Energy Analyzer tool with hourly consumption exports in CSV/XML, and ENERGY STAR Portfolio Manager integration, but does not yet support Green Button or a developer API.
Connecticut Natural Gas Corporation Rate Schedule Comparison
| Schedule | Type | Rate | Best For |
|---|---|---|---|
| SGS | Commercial | ~$1.09/CCF all-in (EIA commercial benchmark) | Small commercial gas loads |
| MGS | Commercial | Declining-block distribution + PGA (tariff) | Mid-size C&I (5,000-30,000 CCF/yr) |
| LGS | Industrial | ~$0.87/CCF all-in (EIA industrial benchmark) | Large C&I (30,000+ CCF/yr) |
| TS / Interruptible | Industrial | Delivery-only / curtailable pricing | Customers shopping commodity or with dual-fuel flexibility |
Market Overview
CNG is a PURA-regulated local distribution company. Connecticut permits competitive retail gas supply, so C&I customers can shop the commodity portion of their bill from licensed suppliers while CNG provides regulated delivery.
Need to pull your actual usage data to compare rates? See the Connecticut Natural Gas Corporation Data Access Guide →
Current Rate Schedules
CNG rates combine a fixed customer charge, a per-CCF distribution (delivery) charge that increases for larger general-service classes, and a Purchased Gas Adjustment passing through the commodity cost. Exact per-CCF delivery charges are set in CNG's PURA-approved tariff (2026 schedules effective 05/01/2026). EIA reports Connecticut delivered gas prices for January 2026 of roughly $10.87/Mcf commercial and $8.65/Mcf industrial (about $1.09 and $0.87 per CCF), useful as an all-in benchmark.
Effective: May 1, 2026 · Full Tariff Book →
| Schedule | Type | Applicability | Structure | Rate |
|---|---|---|---|---|
| Small General Service (SGS) | commercial | Small commercial customers below the MGS consumption threshold. | Fixed monthly customer charge plus per-CCF distribution charge; Purchased Gas Adjustment passed through. See PURA tariff for exact charges. | ~$1.09/CCF all-in commercial benchmark (EIA Jan 2026) |
| Medium General Service (MGS) | commercial | Commercial/industrial customers using roughly 5,000-30,000 CCF annually. | Fixed customer charge plus declining-block per-CCF distribution charge; daily-demand metering and a Daily Demand Metering Charge may apply; PGA passed through. | Per-CCF distribution charge per PURA tariff (figures not published online) |
| Large General Service (LGS) | industrial | Large commercial/industrial customers using 30,000+ CCF annually. | Fixed customer charge plus per-CCF distribution charge with daily-demand metering; PGA passed through. Lowest per-unit delivery rates of the firm classes. | ~$0.87/CCF all-in industrial benchmark (EIA Jan 2026) |
| Transportation Service (TS) | industrial | Large customers who purchase the gas commodity from a third-party supplier and pay CNG only for delivery. | Distribution-only charges (no CNG commodity); customer arranges supply with a licensed marketer. See Rate TS tariff sheet. | Delivery-only per PURA tariff |
| Interruptible Service | industrial | Large dual-fuel customers willing to be curtailed during peak demand in exchange for lower rates. | Interruptible commodity/delivery pricing; PURA publishes monthly interruptible gas rates. Subject to curtailment. | Monthly interruptible rate per PURA filing |
Rate Recommendations by Use Case
Mid-size commercial facility (office, retail, multi-tenant)
Match the account to Medium General Service and use Energy Analyzer to manage seasonal heating peaks.
MGS covers ~5,000-30,000 CCF/yr with declining-block delivery charges; daily-demand metering enables peak management.
- Export hourly usage from Energy Analyzer in CSV to spot heating peaks
- Verify you are not over/under the MGS threshold
- Consider shopping the commodity to hedge the PGA
Large industrial / high-volume manufacturer
Use Large General Service with daily-demand metering and evaluate Transportation or Interruptible service.
LGS offers the lowest per-unit firm delivery rates; TS lets you buy commodity competitively and interruptible cuts cost for dual-fuel sites.
- Compare PGA against marketer offers before choosing TS
- Use daily-demand interval data to manage maximum-day contract requirements
- Model curtailment risk before electing interruptible
Multi-site commercial or municipal portfolio
Automate consumption data into ENERGY STAR Portfolio Manager via SmartBuildings CT for benchmarking and procurement.
Portfolio-wide benchmarking surfaces efficiency and procurement opportunities; SmartBuildings CT provides the automated data transfer for free.
- Enroll eligible buildings in SmartBuildings CT
- Use ESPM EUI to prioritize retrofits
- Aggregate volume to strengthen commodity negotiations
Historical Rate Trends
CNG distribution rates are set in PURA rate cases, while the commodity portion changes monthly through the Purchased Gas Adjustment. The 2026 rate schedules took effect 05/01/2026. Connecticut delivered prices have been volatile month to month; EIA shows the commercial delivered price near $10.87/Mcf in January 2026.
May 1, 2026
2026 rate schedules took effect, including system-expansion variants.
n/a (PURA-approved annual schedule)Overall trend: Distribution rates adjust at PURA rate-case intervals; commodity prices fluctuate monthly via PGA and have been volatile, with winter peaks in the electric-power and citygate prices reported by EIA.
Next expected change: Next annual rate schedule expected to take effect 05/01/2027; PGA updates monthly.
Cost Optimization Strategies
C&I gas customers on CNG can lower costs by matching their rate class to consumption, shopping the competitive commodity, and using interval data to manage peak demand.
Right-size the rate class
For: All C&I gas accounts
Confirm the account is on the correct general-service class (SGS/MGS/LGS) since per-CCF delivery charges decline as the class grows.
Shop the gas commodity
For: C&I customers, especially LGS/TS-eligible
Buy the gas supply from a licensed third-party marketer (or move to Transportation Service) while CNG continues delivery, to lock or beat the Purchased Gas Adjustment.
Use Energy Analyzer interval data
For: MGS/LGS daily-demand accounts
Export hourly/daily consumption to identify peak-driven demand charges and target efficiency or load-shifting.
Interruptible / dual-fuel
For: Large dual-fuel industrial sites
Dual-fuel facilities can take interruptible service for lower rates, accepting curtailment during peaks.
Benchmark via ESPM / SmartBuildings CT
For: Commercial & municipal portfolios
Automate consumption data into ENERGY STAR Portfolio Manager (free via SmartBuildings CT) to find efficiency opportunities across a portfolio.
To implement these strategies, you need your 15-minute interval data. Learn how to download Connecticut Natural Gas Corporation interval data →
Deregulated Market Shopping
Connecticut allows commercial and industrial gas customers to purchase the commodity portion of their bill from licensed third-party suppliers while CNG provides regulated delivery. Large customers can also move to CNG's Transportation Service to fully decouple supply from delivery.
How to Compare Connecticut Natural Gas Corporation Suppliers
- 01Confirm the account is eligible (most C&I accounts are) and gather 12 months of usage
- 02Compare licensed third-party gas suppliers registered with Connecticut PURA
- 03Negotiate a fixed or indexed commodity price and contract term
- 04Enroll with the supplier; CNG continues to bill and deliver, or move to Rate TS for delivery-only billing
Contract Terms for Connecticut Natural Gas Corporation Supply Agreements
- Fixed-price terms (commonly 12-36 months) lock the commodity rate
- Indexed/variable terms float with the market
- Transportation Service (Rate TS) for delivery-only large customers
Common Pitfalls When Shopping Connecticut Natural Gas Corporation Rates
- CNG distribution charges and the Purchased Gas Adjustment still apply on top of supplier pricing
- Watch for early-termination fees and variable-rate roll-overs
- Verify the supplier is PURA-licensed before signing
Frequently Asked Questions
Can a consultant pull our facility's gas consumption data programmatically?▾
Not via a developer API. The practical path is ENERGY STAR Portfolio Manager integration (often set up for free through SmartBuildings CT), which delivers automated monthly billing and consumption data. For ad hoc interval data, the customer can export hourly usage from Energy Analyzer in CSV/XML, or sign a Customer Information Disclosure Authorization letting CNG release data to the consultant.
What rate schedule applies to a large commercial or industrial gas account?▾
Medium General Service (MGS) covers roughly 5,000-30,000 CCF annually and Large General Service (LGS) covers 30,000+ CCF annually. Both can carry daily-demand metering and a Daily Demand Metering Charge. Seasonal (SE) variants and interruptible/transportation options exist for larger or flexible loads.
How far back does CNG data go for C&I accounts?▾
The online portal holds 13 months of billing statements, and Energy Analyzer holds 24+ months of consumption data. Older records can be requested from Customer Care (5-10 business days, possible fee).
Is the gas supply portion of our bill open to competitive shopping?▾
Yes. Connecticut allows commercial and industrial customers to buy the gas commodity from a licensed third-party supplier while CNG continues to deliver it. CNG's distribution (delivery) charges and the Purchased Gas Adjustment still apply regardless of supplier.
Does CNG support EDI for ESCOs or aggregators?▾
Only in a limited form tied to benchmarking compliance (EnergyCAP, ESPM). CNG has no published formal NAESB EDI trading-partner program; ESCOs and aggregators should contact Customer Care to arrange data sharing under the Gas Code of Conduct.
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