HomeWattCost

United Illuminating (UI) rates

UI has 2 residential plans modeled here. For a typical Connecticut home using 699 kWh a month, the cheapest plan open to any household is Rate RT, at about $187 a month.

Investor-owned 312,291 residential customers (EIA-861, 2024) Tariffs checked September 28, 2026

Typical all-in priceRate RT

26.7¢/kWh
Rate R$199/mo
Rate RT$187/mo

Prices assume UI Standard Service supply (the default if you have not chosen a third-party supplier), set July 1 - December 31, 2026.

Residential plans

PlanTypeFixed/moJuly pricesJanuary pricesJuly weekday windows
Rate R
Residential Rate R (Standard Service supply)
Flat $13.02 26.5¢ all hours 26.5¢ all hours None
Rate RT
Residential Time-of-Use Rate RT (Standard Service supply)
Time-of-use $13.02 Off-peak 21.5¢ · Peak 33.4¢ Off-peak 21.5¢ · Peak 33.4¢ Peak noon–8 pm

Rate RT: price by hour

July weekday. Same pricing all year.

Off-peakPeak
21.5¢33.4¢21.5¢12a3a6a9a12p3p6p9p12a

UI peak hours and cheapest times

What are UI’s peak hours?

It depends on the plan. Rate RT: Peak noon–8 pm, on weekdays, all year; weekends: off-peak all day. Hours are local clock time.

When is electricity cheapest on UI?

On summer weekdays the lowest price is Rate RT: 8 pm–noon next day at 21.5¢/kWh, against 33.4¢ at the peak. Rate R charges the same price at every hour.

Which UI plan is cheapest?

For a typical Connecticut home using 699 kWh a month, Rate RT at about $187 a month (26.7¢/kWh all-in, before taxes). With an EV charged at its cheapest hour, Rate RT gives the lowest total.

Charging an EV on UI

1,000 miles a month in a Tesla Model Y Long Range AWD (275 kWh from the wall, EPA 27.5 kWh/100 mi) at 7.2 kW, added to a typical Connecticut home’s use, on each plan’s cheapest start hour versus plugging in at 6 pm. Averaged over the year.

PlanBest startCharging, best startCharging from 6 pmWhole bill with EV
Rate RAny$73/mo$73/mo$272/mo
Rate RT12 am$59/mo$82/mo$246/mo

With an EV charged at its best hour, the cheapest plan overall is Rate RT. Compare plans on your own usage.

Cost to charge each EV on UI Rate RT

1,000 miles a month at 7.2 kW, starting at 12 am, the plan’s cheapest hour, added to a typical Connecticut home’s bill. Full charge: the EPA range, at the plan’s lowest price (21.5¢/kWh). EPA efficiency, from the wall.

ModelkWh/100 mi1,000 mi a monthFull charge
Lucid Air Pure (2027)23.1$50/mo$20.83
Tesla Model Y Standard RWD (2026)24.3$52/mo$16.74
Tesla Model 3 Standard RWD (2026)24.3$52/mo$16.74
Tesla Model 3 Premium RWD (2026)24.6$53/mo$19.17
Toyota bZ (2027)25.5$55/mo$17.19
Hyundai Ioniq 6 RWD (2025)26$56/mo$19.09
Tesla Model S (2026)27.1$58/mo$23.85
Tesla Model Y Long Range AWD (2026)27.5$59/mo$19.30
Nissan Leaf 75 kWh (2026)27.8$60/mo$18.08
Chevrolet Bolt (2027)28.2$61/mo$15.86
BMW i4 eDrive40 (2026)28.5$61/mo$20.37
Kia EV3 Long Range FWD (2027)29$62/mo$19.98
Volvo EX30 Single Motor (2026)29.2$63/mo$16.36
Kia EV6 Long Range RWD (2026)29.6$64/mo$20.27
Volkswagen ID.4 (2026)29.8$64/mo$18.61
Hyundai Ioniq 5 RWD (2027)30$64/mo$20.48
Ford Mustang Mach-E RWD Extended Range (2026)30.7$66/mo$21.09
Chevrolet Equinox EV FWD (2027)31.1$67/mo$21.30
Tesla Model X (2026)32.2$69/mo$24.33
Chevrolet Blazer EV FWD (2027)32.3$69/mo$21.63
Honda Prologue FWD (2026)32.5$70/mo$21.49
Nissan Ariya FWD 87 kWh (2026)34.4$74/mo$21.34
Cadillac Lyriq RWD (2027)36.8$79/mo$25.75
Hyundai Ioniq 9 AWD (2027)38$82/mo$26.10
Kia EV9 Long Range RWD (2026)38$82/mo$24.88
Tesla Cybertruck AWD (2026)42.9$92/mo$29.93
Rivian R1S Premium (2027)42.9$92/mo$27.63
Rivian R1T Premium (2027)42.9$92/mo$27.63
Chevrolet Silverado EV Extended Range WT (2026)47.8$103/mo$43.50
Ford F-150 Lightning Extended Range (2025)47.9$103/mo$32.90

How UI’s plans work

Rate R (Residential Rate R (Standard Service supply)). One price per kWh at every hour, all year: 26.5¢. Shifting use to other hours changes nothing on this plan; using less is the only lever. Fixed charge: $13.02 a month.

Rate RT (Residential Time-of-Use Rate RT (Standard Service supply)). Peak noon–8 pm on July weekdays; 8 of 24 hours carry the top price of 33.4¢. The cheapest July weekday hour costs 21.5¢, so moving 1 kWh out of the top hours saves 11.9¢. January weekdays range from 21.5¢ to 33.4¢. Weekends differ: off-peak all day. Fixed charge: $13.02 a month.

Prices on this page are all-in per kWh, before taxes: base rates, supply and every per-kWh rider in the utility’s current tariff sheets. Your bill shows them as separate lines, and riders can change between tariff revisions.

As a cross-check, UI billed its residential customers an average of 34.04¢ per kWh in 2024 (revenue ÷ sales, EIA-861). A plan taken from URDB is shown only if its all-in price is consistent with that figure, adjusted for Connecticut’s price change since.

Sources for each plan

Plans marked “Checked” were transcribed from the utility’s current tariff and rider sheets, all charges included, and are re-checked on the date shown in each file. Other plans come from the OpenEI U.S. Utility Rate Database (CC BY 4.0) and have not yet been checked line by line against the utility’s tariff. Always confirm the current rates on your utility’s website before switching plans.

Compare two UI plans

Run the numbers on UI