What is kWh
A kilowatt-hour (kWh) is the unit of electrical energy equivalent to one kilowatt (kW) of power used for one hour. It is the standard billing unit for electricity in most of the world, including India. 1 kWh = 1000 watt-hours = 3.6 megajoules.
All retail electricity billing, solar yield measurement, PPA pricing, regulatory energy accounting and consumer-facing energy data is denominated in kWh. The unit bridges power, time and cost into a single intuitive quantity.
For Indian solar, kWh is the unit of generation (annual yield in kWh, monthly export in kWh), the unit of consumption offset (kWh saved against retail bill), and the unit of credit under net metering (kWh exported and credited).
Why kWh matters
Universal billing unit. Every Indian electricity bill is in kWh.
PPA pricing. ₹/kWh is the standard tariff format.
Solar yield. Specific yield in kWh/kWp/year is the standard performance metric, as explained in our solar yield glossary entry.
Customer comparison. Solar saves a specific number of kWh, compared to retail tariff per kWh — a saving customers can estimate with a solar cost and savings calculator.
Net metering. Export and import credited in kWh under net metering, which differs from gross metering in how credits are calculated.
Regulatory benchmarking. CUF derived from kWh against capacity.
How kWh is calculated
For variable loads: kWh = ∫P(t) dt over the period
Technical deep dive
Typical Indian household kWh consumption
| Appliance | Approximate kWh per month |
|---|---|
| 1.5 ton AC, 6 hours/day summer | 360 |
| Fridge, 24 hours | 36 to 60 |
| 5 LED bulbs, 6 hours/day | 6 |
| 2 fans, 12 hours/day | 30 |
| Geyser, 30 min/day | 60 |
| TV, 4 hours/day | 12 |
| Washing machine, 2 cycles/week | 16 |
| Microwave, 30 min/day | 21 |
| Computer, 4 hours/day | 24 |
| Total typical Indian family | 200 to 500 |
Indian retail tariff slabs (illustrative)
| Slab | Approximate tariff (₹/kWh) |
|---|---|
| 0 to 100 kWh | 3.00 to 4.50 |
| 101 to 300 kWh | 5.00 to 7.50 |
| 301 to 500 kWh | 7.00 to 9.00 |
| Above 500 kWh | 8.50 to 12.00 |
State-specific. Always consult the current tariff order.
Solar generation per kW per region (annual kWh)
| Region | Annual generation per kW (kWh) |
|---|---|
| Rajasthan utility tracker | 1,800 to 2,000 |
| Gujarat utility fixed | 1,650 to 1,800 |
| Delhi rooftop residential | 1,350 to 1,500 |
| Mumbai rooftop residential | 1,300 to 1,500 |
| Bengaluru rooftop residential | 1,400 to 1,550 |
| Kolkata rooftop residential | 1,200 to 1,400 |
For a full state-by-state breakdown of these benchmarks, see our guide to solar yield in India.
Multiples and submultiples
| Unit | Value |
|---|---|
| Wh | 1 watt-hour |
| kWh | 1,000 Wh |
| MWh | 1,000 kWh |
| GWh | 1,000 MWh |
| TWh | 1,000 GWh |
Real-world applications
Electricity billing for all customer categories.
PPA tariff pricing, which feeds into generation and revenue financial modeling.
Solar yield reporting.
State-wise generation reporting by CEA.
Energy intensity benchmarking.
Demand response payments.
Common kWh problems
Meter inaccuracy (older meters drift).
Billing slab boundary effects (small variation pushing into higher slab).
Net metering credit miscalculation, often traceable back to unfamiliarity with the net metering application process.
Time-of-day rate confusion.
Tampering allegations on smart meter.
Best practices
Verify smart meter readings against own observations.
Audit first three monthly bills after installation.
Use accurate-class meters (0.5S for C&I, 1.0 for residential).
Track ToD usage where applicable to optimise cost.
Maintain solar generation logs to support net metering claims.
Indian market context
PM Surya Ghar promises up to 300 kWh/month free electricity for participating residential customers.
CEA monthly reports publish state-wise generation in MWh and TWh.
CERC and SERC tariff orders set ₹/kWh slab rates.
Smart meter rollout under RDSS provides 15-minute interval kWh data.
Time-of-day tariff rules notified in 2023 allow differential ₹/kWh pricing across time slots.
Standards and certifications
| Standard | Scope |
|---|---|
| IEC 80000-1 | SI units |
| IS 16444 | Indian smart meter standard |
| IEC 62052-11 | Energy meter requirements |
| IEC 62053-22 | Static meter for active energy |
| CEA Smart Meter Regulations 2023 | Indian metering |
Key takeaways
A kWh is the unit of electrical energy equal to one kilowatt of power used for one hour. It is the universal billing unit for Indian electricity, the standard for solar yield measurement, and the basis for PPA pricing. Customer bills, solar generation, net metering credits and regulatory benchmarking all run on kWh.
Further reading
For how kWh plays out in real projects, these guides go deeper:
- How Much Electricity Does Solar Generate in India?
- Solar Yield in India, kWh-per-kW Benchmarks by State
- Off-Grid Solar Battery Bank Sizing for India
- LCOE of Solar in India: ₹4.8/kWh for a 50 kW C&I Plant
Sources
- IEC 80000-1, SI Units.
- IS 16444, Indian smart meter standard.
- IEC 62052-11, IEC 62053-22, energy meter requirements.
- CEA Smart Meter Regulations 2023.
- State SERC tariff orders.
- PM Surya Ghar Muft Bijli Yojana scheme guidelines.
- CEA Monthly Renewable Energy Reports.
- IEA Energy Statistics.
- Forum of Regulators publications.
Frequently Asked Questions
What is kWh in simple words?
What does kWh stand for?
How is kWh calculated?
Is kWh same as units of electricity?
How many kWh does a 3 kW solar system generate?
What is the difference between kW and kWh?
What is the cost of 1 kWh in India?
Is kWh used in PPAs?
How is kWh measured?
What is MWh?
What is GWh and TWh?
How many kWh does a typical Indian home use?
How is kWh billed?
What is unit metering?
How accurate is kWh measurement?
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Co-founder & CEO driving Qbits Energy's product strategy and growth across India.