Solar Generation Per kWp by Indian State 2026

Solar generation in India is not one number. The same 1 kWp (kilowatt-peak) of panels installed in Jaisalmer produces nearly 50% more electricity per year than the same panels mounted in Guwahati. Across the country, annual generation per kWp ranges from 1,100 kWh in the cloudy north-east to 1,800 kWh in dry western Rajasthan, with a national residential rooftop average of about 1,500 kWh/kWp/year. The drivers are well understood — peak sun hours (PSH), ambient temperature, dust load, monsoon length, and panel technology — and they explain almost every gap between a vendor’s sales-deck promise and the actual meter reading on a customer’s roof.

This guide collects the per-state generation numbers we use during site design at Heaven Green Energy, traces them back to the MNRE Solar Atlas and NREL India resource data, and gives you a 5-factor calculator to set realistic expectations before signing any contract.

Direct answer. Annual solar generation per kWp installed in India ranges from about 1,100 kWh in the north-east and 1,200 kWh in coastal Kerala to 1,800 kWh in western Rajasthan. The national residential rooftop average is 1,500 kWh/kWp/year, equivalent to a Capacity Utilisation Factor (CUF) of about 17%. State variation is driven by peak sun hours (3.8–6.5/day), temperature derating, monsoon length, dust, and panel technology choice.

If you’ve been quoted a fixed “4 units per kW per day” generation figure regardless of your state, that’s a sales shortcut, not a number you can plan against. The next sections give you the state-specific numbers your installer should be modelling on, and the seasonal swings that hide inside every annual average.

Why Solar Generation Varies Across India

Solar panels are rated under Standard Test Conditions (STC) — 1,000 W/m² irradiance, 25°C cell temperature, 1.5 air mass. Real rooftops in India never meet STC for more than a few minutes a year. What you actually get depends on how many hours of usable sunshine your latitude sees, how hot the panel runs, how much dust settles between cleanings, how many weeks the monsoon covers your sky, and which generation of cell technology you bought.

A 1 kWp system in Bikaner sees 6.3 PSH/day on average, runs at 55–65°C cell temperature in May, gets dust-cleaned by occasional desert winds, and loses about three weeks to active monsoon. The same 1 kWp in Kochi sees 4.6 PSH/day, runs cooler at 45–55°C, stays cleaner thanks to monsoon rain washing, but loses 12–14 weeks to heavy cloud cover from June to September. The Bikaner system delivers 1,750 kWh/year. The Kochi system delivers 1,300 kWh/year. Both are well-designed; the geography sets the ceiling.

The National Renewable Energy Laboratory (NREL) maintains long-term irradiance datasets for India through its International Programs division, and ISRO Bhuvan publishes the Solar Atlas tiles that DISCOMs and EPCs reference for feasibility studies. Together these give us roughly 25 years of validated state-level resource data.

The 5-Factor State Solar Generation Calculator

Across hundreds of installations from Jaisalmer to Visakhapatnam, we use a five-factor framework to estimate annual generation for any site in any Indian state. It’s the same model you should ask your installer to walk you through before you sign — if they can’t break the number down across these five inputs, the quoted generation is a guess.

Factor 1: Peak Sun Hours (PSH)

PSH is the number of hours per day where solar irradiance averages 1,000 W/m² — effectively the conversion factor between installed kWp and daily kWh. Rajasthan’s western belt sees 5.5–6.5 PSH/day. Kerala sees 4.5–4.8 PSH. The all-India residential average is 4.8–5.2 PSH. PSH is the single biggest determinant of annual generation and is the only factor you cannot change after picking your site.

Factor 2: Ambient Temperature and Cell Derating

Silicon solar cells lose about 0.35–0.45% of output for every 1°C above 25°C. Indian rooftop cell temperatures routinely reach 55–70°C in summer, meaning a 12–20% real-time output drop versus the STC rating. Rajasthan summers push derating harder than coastal Karnataka summers, even though Rajasthan has more PSH overall. The Nominal Operating Cell Temperature (NOCT) rating on your panel datasheet is the closer-to-reality number you should plan against.

Factor 3: Dust and Soiling Load

Dust accumulation cuts output by 8–15% in arid states between cleanings. Rajasthan, Gujarat’s Kutch belt, Haryana, and Punjab carry the heaviest dust load — biweekly cleaning is the practical minimum. South humid states and the west coast self-clean through monsoon, so soiling losses are 3–6% on annual average. Our Rajasthan dust and heat field guide walks through the cleaning schedules that hold annual generation within 4% of the modelled figure.

Factor 4: Monsoon Weeks

The number of weeks where heavy cloud cover suppresses irradiance below 200 W/m² for most daylight hours. Western Rajasthan loses 2–3 weeks. Mumbai and the Konkan coast lose 10–12. Kerala loses 12–14. Assam and West Bengal lose 14–16. Each lost week reduces annual generation by 1.5–2% of the theoretical maximum.

Factor 5: Panel Technology (TOPCon vs Mono-PERC)

Cell technology shifts annual yield by 2–5%. TOPCon panels (Tunnel Oxide Passivated Contact) have lower temperature coefficients than Mono-PERC, which means they hold output better through Indian summers. Across a 25-year life that 3% compounds to an extra 1,100–1,400 kWh per kWp, often worth the small price premium. We compared the technologies in detail in our TOPCon vs Mono-PERC India heat analysis.

State Solar Generation Rankings 2026

Below is the per-state generation table we use during pre-sales site design. Figures are typical residential rooftop annual generation per kWp installed, assuming a tier-1 panel, properly tilted south-facing array, performance ratio of 0.75–0.80, and standard fortnightly cleaning. These are averages — individual sites swing ±5% depending on shading, tilt, and inverter sizing.

State / Region	Annual Generation (kWh/kWp)	PSH (hours/day)	Notes
Rajasthan (western)	1,700–1,800	5.5–6.5	Highest in India; dust offsets some gain
Gujarat	1,550–1,650	5.4–5.8	Kutch matches Rajasthan; coast lower
Madhya Pradesh	1,500–1,600	5.1–5.5	Central plateau, low cloud cover
Maharashtra	1,500–1,600	5.0–5.5	Interior higher than Konkan coast
Karnataka	1,500–1,600	5.2–5.5	Bangalore plateau cooler — good performance
Tamil Nadu	1,500–1,600	5.4–5.6	Coimbatore and inland strongest
Andhra Pradesh	1,500–1,600	5.2–5.5	Rayalaseema region near-Rajasthan-grade
Telangana	1,500–1,600	5.2–5.5	Hyderabad belt very consistent
Punjab / Haryana	1,500–1,600	5.0–5.4	Dusty winters reduce November–January output
Uttar Pradesh	1,400–1,550	4.8–5.2	Winter fog suppresses December–January
Bihar	1,300–1,450	4.5–4.9	Monsoon and winter haze both hit
Jharkhand	1,300–1,450	4.6–5.0	Hill terrain creates micro-variation
Odisha	1,300–1,450	4.6–5.0	Cyclone weeks reduce coastal output
West Bengal	1,200–1,350	4.0–4.5	Long monsoon plus winter cloud
Kerala	1,200–1,400	4.5–4.8	Longest monsoon; humid but clean
Goa	1,300–1,450	4.6–4.9	Konkan monsoon, otherwise strong
North-East	1,100–1,300	3.8–4.4	Highest cloud cover in India
India average	1,500	4.8–5.2	Residential rooftop, weighted by installs

Source: composite of MNRE Solar Atlas (2024), NREL India irradiance dataset, and Heaven Green Energy field measurements across 320+ commissioned residential systems through 2024–25.

North India: Rajasthan, Gujarat, Punjab, Haryana, UP

The north Indian belt covers the highest-generation region in the country (Rajasthan) and one of the most challenging (eastern UP). What unifies the belt is dry winters with crisp skies, hot summers with hard derating, and dust as a permanent operations concern.

Rajasthan is the benchmark — 1,700–1,800 kWh/kWp/year across Jaisalmer, Bikaner, Barmer, and the Jodhpur belt; Jaipur and the eastern districts run closer to 1,650 kWh. Summer cell temperatures touch 70°C, which is why TOPCon (with its better temperature coefficient) outperforms Mono-PERC by 4–5% over a Rajasthan year.

Gujarat mirrors Rajasthan in Kutch and Saurashtra (1,600–1,650 kWh) but drops to 1,500–1,550 kWh along the coast and in south Gujarat as humidity rises.

Punjab and Haryana sit at 1,500–1,600 kWh — strong summer generation, but winter fog from late November through January knocks December output down 25–30% versus October. Plan your annual budget around this dip; it’s the single biggest mistake we see in north Indian quotes.

Uttar Pradesh is the most variable. Western UP (Meerut, Agra) runs 1,500–1,550 kWh. Eastern UP (Lucknow, Varanasi, Gorakhpur) drops to 1,400–1,450 kWh due to higher winter fog incidence. Bundelkhand runs higher again at 1,500 kWh.

Mid-CTA — see your state’s number on your actual bill. Our solar calculator takes your PIN code and your monthly consumption, then runs the 5-factor model against MNRE Solar Atlas data for your district. Free, two minutes. Try the solar calculator →

Central India: MP, Maharashtra, Chhattisgarh

Central India is the most stable belt in terms of annual generation — fewer monsoon weeks than the east, less dust than the north-west, and high enough latitude to keep cell temperatures from sustained extremes.

Madhya Pradesh runs 1,500–1,600 kWh/kWp/year across the Malwa plateau, Indore-Bhopal corridor, and the Narmada belt. Gwalior and the north-MP districts touch 1,600 kWh. The state’s own subsidy is small, but the irradiance is among the best for the latitude band.

Maharashtra splits sharply. Interior Maharashtra (Pune, Nashik, Aurangabad, Vidarbha) delivers 1,550–1,600 kWh — Vidarbha is functionally a Rajasthan-adjacent generation zone. The Konkan coast (Mumbai, Thane, Raigad, Ratnagiri) drops to 1,400–1,500 kWh as monsoon cover extends from June through mid-September. Mumbai itself rarely exceeds 1,450 kWh.

Chhattisgarh runs 1,450–1,550 kWh, with Raipur and Bilaspur on the higher end. The state’s central position keeps cyclone exposure low and monsoon weeks moderate.

South India: Karnataka, Tamil Nadu, AP, Telangana

The southern belt has the most predictable irradiance in India — modest peaks, modest troughs, and a long usable solar year across both monsoons.

Karnataka generates 1,500–1,600 kWh/kWp/year. Bangalore’s plateau altitude (920m) keeps cell temperatures 5–8°C lower than the southern Tamil Nadu plains, which means lower derating and stronger summer output. Coastal Karnataka (Mangalore, Udupi) drops to 1,350–1,450 kWh due to south-west monsoon exposure.

Tamil Nadu delivers 1,500–1,600 kWh inland (Coimbatore, Salem, Tiruchi) but only 1,400–1,500 kWh on the coast (Chennai, Cuvery delta) thanks to north-east monsoon weeks from October to December. The state has the second-highest installed rooftop solar base in India and the most mature net-metering framework in the south.

Andhra Pradesh runs 1,500–1,600 kWh, with Rayalaseema (Anantapur, Kurnool, Kadapa) at the upper end — these districts have irradiance close to Rajasthan-grade with cooler temperatures.

Telangana is consistent at 1,500–1,600 kWh across Hyderabad and the northern districts. Low cyclone exposure and moderate monsoon make Telangana one of the most predictable generation zones in India.

East India: West Bengal, Odisha, Jharkhand, Bihar

The eastern belt is where vendor promises diverge most sharply from real generation. A “5 kWh/kW/day” claim is normal in sales decks; the meter says 3.5–3.8 kWh on the annual average.

Bihar generates 1,300–1,450 kWh/kWp/year. Patna and the central districts top the range; north Bihar (Darbhanga, Madhubani) sits lower because of winter fog. Sanctioned-load constraints often limit system sizing — see our 3 kW vs 5 kW vs 10 kW sizing guide before quoting.

Jharkhand runs 1,300–1,450 kWh, with the Chota Nagpur plateau slightly better than the southern lowlands. Hill shading and forest cover create more site-level variation than any other east Indian state.

Odisha delivers 1,300–1,450 kWh. Coastal Odisha (Puri, Cuttack) is at the lower end because of cyclone-weeks during October–November on top of the south-west monsoon. Western Odisha (Sambalpur, Sundargarh) generates closer to 1,500 kWh — closer to Chhattisgarh-grade.

West Bengal has the longest annual cloud cover in mainland India outside the north-east. Annual generation is 1,200–1,350 kWh. Kolkata typically registers 1,250 kWh. North Bengal hills are lower again. Anyone quoting West Bengal at 1,500 kWh/kWp is using national-average numbers, not state-specific data.

West Coast + Kerala: Goa, Kerala, Coastal Maharashtra

The west coast is the high-humidity, long-monsoon zone of India. Annual generation is below average but seasonal stability through winter is excellent because monsoon weeks don’t extend past September.

Goa generates 1,300–1,450 kWh/kWp/year. South Goa sees a slightly longer monsoon than North Goa. The lack of dust and frequent monsoon rain-washing keep the soiling losses among the lowest in India — 2–3% annual versus 8–10% in Rajasthan.

Kerala is at 1,200–1,400 kWh, the lowest in the southern peninsula. Thiruvananthapuram tops the range; Kochi, Kozhikode, and Wayanad cluster lower. Two monsoons (south-west June–September, north-east October–November) cap usable solar weeks at 36–38 per year against 49–50 in Rajasthan. Despite this, Kerala’s high domestic tariffs (KSEB slab 5 sits at ₹8.10/kWh) keep payback periods inside 5 years.

Coastal Maharashtra (Konkan belt) runs 1,400–1,500 kWh — better than Kerala because the monsoon is shorter, worse than interior Maharashtra because the cloud cover is heavier. Mumbai rooftops should be modelled at 1,400–1,450 kWh, not the 1,550 kWh many quotes assume.

Seasonal Variation — Summer vs Monsoon vs Winter Generation

Annual generation hides huge month-to-month swings. A 1 kWp system in Mumbai might generate 150 kWh in March and 55 kWh in July. The same system in Jaipur generates 180 kWh in March and 105 kWh in July. Sizing your system against annual averages without budgeting for monsoon dips is the most common cause of “my solar isn’t working” complaints in the first year.

Month	Rajasthan (kWh/kWp)	Gujarat	Maharashtra (coast)	Tamil Nadu	Kerala	West Bengal
Jan	130	125	130	135	110	95
Feb	140	135	140	145	120	105
Mar	165	160	155	160	130	120
Apr	175	170	160	155	125	125
May	180	165	145	145	110	120
Jun	150	130	80	130	70	100
Jul	130	105	55	115	60	80
Aug	125	100	60	120	65	85
Sep	140	125	95	130	90	95
Oct	155	145	140	110	95	110
Nov	140	135	135	100	95	105
Dec	125	120	125	110	105	95

Source: Heaven Green Energy 36-month rooftop production telemetry, normalised to 1 kWp installed capacity.

• Summer (March–May) is the peak generation window for most of India, though Tamil Nadu, Kerala, and the deep north-east see flatter curves because their humidity reduces panel surface clarity.
• Monsoon (June–September) is the deepest dip — Mumbai loses 60–65% of peak-month output, Kerala loses 55–60%, Rajasthan only 15–20%. Always plan your annual savings target with these dips priced in.
• Winter (November–February) delivers 10–15% below peak across most states. Cool ambient temperatures help cell efficiency, but the lower solar angle and (in north India) winter fog drag total daily kWh down.

Common Generation Estimation Mistakes

Across the residential and commercial quotes we audit for clients, six estimation errors keep recurring. Each one inflates the projected savings by 8–25%, which means the payback period the customer is shown is shorter than the one they actually experience.

1. 1
   Using a national 4–5 kWh/kW/day average. Your installer should use state-specific PSH from the MNRE Solar Atlas, not a generic India figure. A West Bengal site quoted at 4.5 kWh/kW will under-deliver by 18%.
2. 2
   Ignoring temperature derating. A 350 W panel rated at STC delivers 280–300 W on a 60°C rooftop. Honest quotes apply an 80% performance ratio, not a 90% one.
3. 3
   Assuming Standard Test Conditions year-round. STC happens for minutes, not months. Use Nominal Operating Cell Temperature (NOCT) figures from the datasheet for any annual yield model.
4. 4
   Skipping the soiling loss line. Dust-belt states lose 8–15% to soiling between cleanings. If your quote shows zero soiling losses, it is overestimating annual generation by 6–10%.
5. 5
   Modelling at 0% annual degradation. Tier-1 panels degrade 0.4–0.5% per year. Over 25 years, that's a 10–12% drop. Year-25 generation is not year-1 generation.
6. 6
   Ignoring shading audits. A single morning-shadow water tank can cut a string's output 15–25%. A proper site survey uses a shading analyser or drone, not a "looks open from the ground" assumption.

For the financial impact of these estimation errors, work through our solar ROI calculation guide — the worked examples show how a 12% overstatement of generation extends payback by 6–8 months.

North Dry vs South Humid — Trade-Offs

The two big climatic zones for Indian rooftop solar — north dry (Rajasthan, Gujarat, Haryana, west MP) and south humid (Karnataka, Kerala, coastal AP/TN) — each have generation profiles, maintenance demands, and equipment-selection implications that pull in opposite directions.

Verdict. North dry states deliver more kWh per kWp installed. South humid states deliver more kWh per rupee invested, because higher tariffs and lower equipment derating compress payback even with lower generation. Both work financially — the right choice is whatever matches the state you actually live in. Beware any installer who quotes Rajasthan-grade numbers for a Mumbai or Kochi rooftop.

For a state-tariff-adjusted payback comparison, work through our solar payback period guide — it walks through Rajasthan, Maharashtra, Karnataka, and Kerala scenarios side-by-side.

How Heaven Green Energy Estimates Generation Per Site

Generation per kWp is not a sales-deck number. It’s a site engineering output. Our pre-quote site survey runs the following process for every residential and commercial enquiry across the 22 Indian states we service:

• PSH lookup — district-level monthly average from MNRE Solar Atlas, cross-checked against NREL India dataset for the nearest validated station.
• Bhuvan satellite roof check — ISRO Bhuvan tiles for shading, neighbour-building height, and clear sky access.
• On-site irradiance probe — physical pyranometer reading during the site survey, taken between 11 AM and 2 PM on a clear day to calibrate against the dataset.
• Temperature derating model — district summer maxima from IMD data, applied against panel datasheet temperature coefficient (Mono-PERC or TOPCon).
• Soiling profile — fortnightly cleaning factored at 6–12% annual loss for dust-belt states, 2–4% for monsoon-belt states.
• 25-year degradation model — 0.45% year-on-year linear degradation for tier-1 ALMM (Approved List of Models and Manufacturers) panels.
• Output: monthly kWh table — you receive a per-month generation forecast, not an annual lump sum, so you can compare against your bill every billing cycle.

This is the same engineering process that backs our generation guarantees on commercial projects. Explore the services that fit your project:

• Residential Solar — site-specific generation modelling for 1–10 kW rooftop systems, PM Suryaghar subsidy handled end-to-end.
• Commercial Solar — 10–500 kW systems with state-tariff-adjusted ROI, accelerated depreciation, and capex-or-opex finance.
• Solar Calculator — input your PIN code and bill, get a state-specific generation and savings estimate in 60 seconds.
• Contact our team — free site survey across north, central, and south India.

Frequently Asked Questions

What is the average solar generation per kWp in India in 2026?

The residential rooftop average across India is approximately 1,500 kWh per kWp per year, or about 4.1 kWh per kW per day. This corresponds to a Capacity Utilisation Factor (CUF) of about 17%. State-specific generation ranges from 1,100 kWh/kWp in the north-east to 1,800 kWh/kWp in western Rajasthan. Always use state or district-level numbers from MNRE Solar Atlas rather than the national average for system sizing — a 20% gap between assumption and reality changes your payback period by 9–12 months.

Which Indian state produces the most solar electricity per kWp installed?

Rajasthan is the highest-generating state in India for residential rooftop solar, with 1,700–1,800 kWh per kWp per year in the western districts (Jaisalmer, Bikaner, Barmer). Peak sun hours reach 5.5–6.5 per day, and the dry climate means low cloud cover. The trade-off is heavy summer derating (cell temperatures reach 65–70°C) and high dust soiling, which together pull 12–18% off the theoretical maximum. Gujarat’s Kutch belt is the next-highest at 1,600–1,650 kWh.

Why does Kerala generate less solar electricity than Rajasthan?

Kerala has fewer peak sun hours (4.5–4.8 per day versus Rajasthan’s 5.5–6.5) and longer monsoon weeks (12–14 weeks versus 2–3). The south-west monsoon from June to September and the north-east monsoon from October to November together cap the usable solar weeks at 36–38 per year, against 49–50 in Rajasthan. The result is annual generation of 1,200–1,400 kWh per kWp, about 25% lower than Rajasthan. Higher Kerala tariffs (₹8.10/kWh at slab 5) partially compensate by speeding payback.

What is CUF and what’s a good CUF for residential rooftop solar in India?

CUF (Capacity Utilisation Factor) is the ratio of actual annual generation to theoretical maximum if the system ran at full nameplate capacity every hour of the year. For India, residential rooftop CUF ranges from 13% (north-east, Kerala) to 20–22% (western Rajasthan), with a national average of about 17%. Commercial open-access ground-mount projects often hit 22–25% CUF because of tracking systems and optimal orientation. For your home rooftop, anything above 16% in central/southern India and above 19% in north-western India is a strong number.

How much does monsoon reduce solar generation each year?

Monsoon reduces month-on-month generation by 30–50% in coastal and heavy-rainfall states (Kerala, coastal Maharashtra, West Bengal, Goa) and by 10–20% in drier states (Rajasthan, Gujarat, Telangana). On an annual basis, monsoon costs the country between 8% and 18% of theoretical maximum generation depending on state. Mumbai’s July output is roughly 55 kWh per kWp versus 155 kWh per kWp in March. Plan your monthly savings target with these dips priced in rather than dividing the annual figure by 12.

Does panel technology (TOPCon vs Mono-PERC) change state-level generation?

Yes. TOPCon panels have a lower temperature coefficient (typically −0.30%/°C versus −0.35%/°C for Mono-PERC), which means they hold output better in hot Indian summers. In Rajasthan, Gujarat, and Vidarbha — where cell temperatures sit at 60–70°C for months — TOPCon delivers 3–5% more annual generation. In Bangalore, Kerala, or hill stations where cells stay cooler, the gap closes to 1–2%. Over a 25-year life, that 3–5% gain translates to 1,100–1,400 extra kWh per kWp.

How can I verify the solar generation number my installer has quoted me?

Three independent cross-checks. First, look up your district on MNRE Solar Atlas or NREL India dataset and compare the PSH against the kWh/kWp/year in your quote. Second, divide the quoted annual generation by 365 and check that the daily figure matches your local PSH × 0.75 (performance ratio). Third, ask the installer for a monthly generation table — anyone who can’t produce monthly numbers is using a national-average shortcut. Heaven Green Energy provides monthly tables for every quote.

Does solar generation degrade over time, and how should I model 25-year output?

Yes. Tier-1 ALMM-listed panels degrade at 0.4–0.5% per year on a linear basis. Year-1 generation is the highest you’ll ever see. By year 25 you’re at roughly 88–90% of year-1 output. For a Rajasthan 1 kWp system, that means 1,750 kWh in year 1 and roughly 1,560 kWh in year 25. Honest ROI models compound this degradation across the projection horizon; quotes that show flat year-on-year generation overstate 25-year savings by 11–13%.