How many units does a 1.5 ton AC use per hour?

As an engineering estimate, roughly 1.2 to 1.8 units an hour while the compressor runs at full load, and less once an inverter model has cooled the room. Over an eight-hour night that is about 6 to 10 units; over a month, 180 to 300 units. The rated power input on the nameplate is the exact figure for your unit.

How much electricity does a 1 ton AC use per hour?

Roughly 0.8 to 1.2 units an hour at full load as a rule of thumb, and a 2 ton unit roughly 1.7 to 2.4. For a monthly estimate, multiply the nameplate input in kW by the hours a day it runs, by about two-thirds for compressor cycling, and by the days in the month.

Why is my electricity bill so high in summer in Delhi?

Delhi's domestic slabs are telescopic: ₹3.00 per unit up to 200 units, ₹4.50 for 201–400, ₹6.50 for 401–800, ₹7.00 for 801–1,200 and ₹8.00 above that (DERC FY 2021-22 schedule, the last published order). Air conditioners push the month into the higher slabs, and an 8% regulatory asset surcharge plus a monthly PPAC of 17.94% (BSES Rajdhani, June 2026) are charged on top. A home going from 300 to 800 units sees its bill rise about 3.4 times, not 2.7.

What are the per unit electricity charges in Delhi?

For domestic connections, ₹3.00 (0–200 units), ₹4.50 (201–400), ₹6.50 (401–800), ₹7.00 (801–1,200) and ₹8.00 (above 1,200) per unit, from DERC's FY 2021-22 schedule, the last tariff order published. Add a fixed charge of ₹20 to ₹250 per kW of sanctioned load a month, an 8% regulatory asset surcharge and the monthly PPAC, which was 17.43% to 18.50% across the three boards in June 2026.

What is the per unit electricity rate in Noida?

Uttar Pradesh urban domestic slabs for FY 2026-27 are ₹5.50 (0–150 units), ₹6.00 (151–300), ₹6.50 (301–500) and ₹7.00 above 500 per unit, plus a fixed charge of ₹110 per kW of sanctioned load a month. These come from secondary summaries of the UPERC order; the order itself was not fetched.

What size solar system do I need to run 2 ACs?

Usually 3 to 5 kW. On the published planning yield a 3 kW system generates about 326 units a month in Delhi and 338 in Noida; 5 kW about 544 and 563. Two 1.5 ton air conditioners run through the night use an estimated 360 to 600 units a month, so 5 kW covers them and 3 kW covers one plus the base load. Size on the twelve-month average, not on June.

Cut your summer AC bill in Delhi and Noida

Q: Does solar cut only the summer bill, or the whole year's?

The whole year. Net metering credits the units you export: in Delhi credits roll over month to month and any surplus at the end of the financial year is paid at the DISCOM's average power purchase cost; in Uttar Pradesh residential users may choose net or gross metering under the 2019 UPERC regulations. Fixed charges stay on every bill.

A summer bill in Delhi or Noida rises faster than the units do. Two or three air conditioners push the month past the slab boundaries at 200, 400 and 800 units in Delhi, or 150, 300 and 500 in Uttar Pradesh, so every extra unit is billed at the dearest rate, and in Delhi an 8% regulatory asset surcharge and a monthly fuel surcharge, 17.94% for BSES Rajdhani in June 2026, are charged on top. A 3 kW rooftop system generates about 326 units a month in Delhi and a 5 kW system about 544 units a month, which is roughly what two air conditioners use in a hot month on the estimate below.

Not yet official. Revised every month; this is the June 2026 figure as reported.

Where the summer units come from

The figures below are engineering rules of thumb for split air conditioners, not measurements of your unit: the nameplate input and the star label are the real numbers.

Two such units add roughly 360 to 600 units to the month; three add 540 to 900. On top sits the base load the winter bill already shows: the refrigerator, lighting, the water pump. A home that reads 250 units in February and 800 in June has not changed its habits; it has switched on the cooling.

To check your own figure, multiply the nameplate input in kW by the hours a day each unit runs, by about two-thirds for compressor cycling, and by the days in the month. The star label's yearly units figure, divided by twelve, is a second rough check.

Why the Delhi bill rises faster than the units

Delhi's domestic energy charges are telescopic: each unit is billed at the rate of the slab it falls in, and the last schedule DERC published, for FY 2021-22, is ₹3.00 (0–200 units), ₹4.50 (201–400), ₹6.50 (401–800), ₹7.00 (801–1,200) and ₹8.00 (above 1,200) per unit. The top rate is more than two and a half times the bottom one. On the energy charge sits a fixed charge by sanctioned load, ₹20 (up to 2 kW), ₹50 (2–5 kW), ₹100 (5–15 kW), ₹200 (15–25 kW) and ₹250 (above 25 kW) per kW per month, then the 8% regulatory asset surcharge on the two together, then the power purchase adjustment charge (PPAC), the fuel surcharge DERC now lets the electricity boards revise every month. In June 2026 it was 17.94% for BSES Rajdhani, 17.43% for BSES Yamuna and 18.50% for Tata Power-DDL. Together the two surcharges add roughly a quarter to the energy and fixed charges.

Not yet official. Revised every month; this is the June 2026 figure as reported.

The calculator makes the effect visible. Take a BSES Rajdhani home with a 5 kW sanctioned load. At 800 units its consumption is 2.7 times a 300-unit month, but its bill is about 3.4 times, because the extra 400 units all land in the 401 to 800 slab and both surcharges are then applied to the larger total. Slabs are why "my bill doubled but my usage did not" is a true sentence in Delhi every June.

Delhi's free-power concession, as reported, is 0–200 units a month free; 201–400 units at 50% off, capped at ₹800 a month; you must opt in. It is written for months of up to 400 units; what a month of 800 units receives is not in the published terms we hold, so the calculator leaves the concession out and shows the tariff bill. With solar, the concession is worked out on net units, that is import minus export, which is how a rooftop system can bring a summer month back inside the band.

Not yet official. Trade and news reports; no DERC or GNCTD order was cited.

Why the Noida bill rises: the Uttar Pradesh slabs

Noida, Greater Noida and Ghaziabad bill on the Uttar Pradesh urban domestic tariff. The FY 2026-27 slabs, which UPERC left unchanged, are ₹5.50 (0–150 units), ₹6.00 (151–300), ₹6.50 (301–500) and ₹7.00 (above 500) per unit, with a fixed charge of ₹110 per kW per month of sanctioned load. The calculator applies no surcharge in Uttar Pradesh and leaves electricity duty out in both states.

Not yet official. Taken from secondary summaries of the FY 2026-27 UPERC order; the order itself was not fetched.

Not yet official. From a secondary summary of the UPERC order.

The ladder is flatter than Delhi's: the top rate is about a quarter above the bottom one. So the same jump from 300 to 800 units on a 5 kW load raises a Noida bill about 2.5 times, close to the 2.7 times the units rose. The catch is where the ladder starts. The lowest Uttar Pradesh rate is above Delhi's second slab, so a Noida home pays more than a Delhi home for a 300-unit winter month and roughly the same for an 800-unit summer one.

Electricity bill calculatorEnter your units and sanctioned load, pick your electricity board for the PPAC, and see the slab, fixed, surcharge and PPAC lines. Then add a solar size and see the bill after it.Open the tool

The Delhi tariff page and the Noida tariff page walk through one bill line by line.

What size solar covers two or three air conditioners

Rooftop solar does not stop the air conditioners drawing power. It puts units into the grid by day and takes them back at night through net metering, so what matters is monthly generation against monthly use. On the planning yield Verde Solaire publishes, with a 10% derate for dust and heat, a 3 kW system generates about 326 units a month in Delhi and about 338 units a month in Noida; a 5 kW system generates about 544 units a month in Delhi and about 563 units a month in Noida. Against the estimate above, 3 kW covers the base load and one air conditioner run through the night; 5 kW covers two, or three run for fewer hours. The scheme's own sizing guide says the same in units: 0–150 units a month: 1–2 kW · 150–300 units: 2–3 kW · above 300 units: above 3 kW.

Three things decide between the two sizes. First, the twelve-month average, not June: the size calculator works from it, and summer alone will oversize the system. Second, the subsidy: the central subsidy is capped at ₹78,000 from 3 kW upwards, so the fourth and fifth kW are paid for in full; the 3 kW or 5 kW guide sets the two side by side. Third, the sanctioned load, which two or three air conditioners usually push to 5 kW or more and which sets the Delhi fixed charge. In Delhi, no feasibility study is needed up to 10 kW on the same supply type, and the DISCOM handles any load increase or transformer upgrade.

Generation is an annual average: long summer days run above it until monsoon cloud and dust pull output down, as the seasonal generation guide explains. Net metering smooths it out: in Delhi credits roll over month to month, and any surplus left at the end of the financial year is paid at the DISCOM's average power purchase cost, and in Uttar Pradesh under the UPERC rooftop solar regulations of 2019, residential users may choose net or gross metering, and the DISCOM allows capacity within transformer limits. Delhi homes up to 3 kW also earn a generation-based incentive of ₹3 per unit generated, about ₹11,745 a year on 3 kW, for 5 years from commissioning, paid monthly against the bill; any excess to the bank account. Prices after subsidy are on the Delhi and Noida pricing pages.

Savings that cost nothing, or nearly nothing

Solar is the large lever, but the cheap ones come first, because a smaller load means a smaller system.

Thermostat. Every degree below what the room needs costs extra compressor hours. 24 to 26 °C with the ceiling fan on is the standard advice; 18 °C on a hot evening is the most expensive habit in the house.
Servicing. A choked filter and a dirty outdoor coil make the compressor run longer for the same cooling. Clean the filter every few weeks in summer and have the coils serviced before the season.
Seal the room. Gaps under doors, a window that does not close and afternoon sun on the glass all add compressor hours.
Timers and sleep mode. A unit cooling an empty room at three in the afternoon is the commonest waste. Sleep mode raises the set point as the room cools.
Replacing an old unit. A ten-year-old fixed-speed air conditioner is often the largest load in the house. A 5-star inverter model of the same tonnage draws less for the same cooling, and the star label's yearly figure lets you compare two before buying.
Read the bill. Check the sanctioned load, which sets the fixed charge, and in Delhi the PPAC line. If the home stays under 400 units, make sure you have opted in to the free-power concession.

Assumptions and limits

Delhi energy and fixed charges are DERC's FY 2021-22 schedule, the last tariff order the regulator has published; secondary sources say the same rates apply in 2026. PPAC values are the June 2026 figures as reported and change every month.
Uttar Pradesh slabs and the fixed charge come from secondary summaries of the FY 2026-27 UPERC order. Greater Noida (NPCL) bills are not modelled separately.
Air-conditioner draw and duty cycle are engineering estimates; the nameplate and the star label govern.
Generation uses the published planning yield of 1,450 units per kW a year for Delhi and 1,500 for Noida, less a 10% derate, averaged across twelve months.
The free-power concession, electricity duty and taxes are not in the calculator.

Questions people ask

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