What affects solar panel generation?

Key factors: 1) Sunshine hours (location) — Rajasthan gets 6.5 hrs/day, northeast gets 4 hrs/day. 2) Panel tilt angle — optimal is latitude ±15°. 3) Shading from trees/buildings — even partial shade reduces output significantly. 4) Panel temperature — efficiency drops ~0.4%/°C above 25°C. 5) Dust and soiling — dirty panels lose 5–15% output. 6) System losses (inverter, wiring) — typically 15–20%.

How do I calculate my solar system generation?

Formula: Daily generation (kWh) = System size (kW) × Peak Sunshine Hours × Performance Ratio (0.8). Example: 5 kW system in Delhi (5.5 sunshine hours) = 5 × 5.5 × 0.8 = 22 kWh/day = 660 kWh/month.

Solar Generation Calculator India 2026

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Solar Unit Generation by System Size (India Average)

At the national average of about 5 peak sun hours and an 82% performance ratio, each 1 kW of rooftop solar produces about 4.1 units (kWh) per day. Sunny Rajasthan and Gujarat produce up to about 5.3 units per kW per day; Assam and the North-East about 3.7.

System size	Units per day	Units per month	Units per year
1 kW	4.1	123	1,496
2 kW	8.2	246	2,993
3 kW	12.3	369	4,490
4 kW	16.4	492	5,986
5 kW	20.5	615	7,483
6 kW	24.6	738	8,979
8 kW	32.8	984	11,972
10 kW	41.0	1230	14,965

So a 3 kW solar panel system produces about 12 units a day, or about 370 units a month, enough for most 2BHK homes. Odd sizes scale the same way: a 3.5 kW system makes about 14.3 units a day and a 4.3 kW system about 17.6. Use the calculator above for your state, panel type and shading, or the free solar calculator for cost and payback.

☀️ City-wise Solar Generation Reference (per kW installed)

City / Region	Peak Sun Hours	1 kW/Day	3 kW/Month	5 kW/Year	Radiation
Jodhpur / Bikaner (Rajasthan)	6.5 hrs	5.3 units	480 units	9,727 units	2373 kWh/m²
Ahmedabad / Surat (Gujarat)	6.2 hrs	5.1 units	458 units	9,278 units	2263 kWh/m²
Bhopal / Indore (MP)	5.8 hrs	4.8 units	428 units	8,680 units	2117 kWh/m²
Delhi / NCR	5.5 hrs	4.5 units	406 units	8,231 units	2008 kWh/m²
Hyderabad (Telangana)	5.5 hrs	4.5 units	406 units	8,231 units	2008 kWh/m²
Vijayawada (AP)	5.5 hrs	4.5 units	406 units	8,231 units	2008 kWh/m²
Pune / Nagpur (Maharashtra)	5.5 hrs	4.5 units	406 units	8,231 units	2008 kWh/m²
Bangalore (Karnataka)	5.3 hrs	4.3 units	391 units	7,931 units	1935 kWh/m²
Mumbai (Maharashtra)	5.3 hrs	4.3 units	391 units	7,931 units	1935 kWh/m²
Lucknow / Agra (UP)	5.2 hrs	4.3 units	384 units	7,782 units	1898 kWh/m²
Chennai (Tamil Nadu)	5.0 hrs	4.1 units	369 units	7,483 units	1825 kWh/m²
Kochi (Kerala)	5.0 hrs	4.1 units	369 units	7,483 units	1825 kWh/m²
Kolkata (West Bengal)	4.8 hrs	3.9 units	354 units	7,183 units	1752 kWh/m²
Patna (Bihar)	4.8 hrs	3.9 units	354 units	7,183 units	1752 kWh/m²
Guwahati (Assam)	4.5 hrs	3.7 units	332 units	6,734 units	1643 kWh/m²

Frequently Asked Questions

How many units does a 1 kW solar panel generate per day?

A 1 kW solar system generates about 3.7 to 5.3 units (kWh) per day in India depending on location and season. Rajasthan and Gujarat get about 5 units/kW/day due to high irradiance; Assam and the North-East about 3.7. The national average is about 4.1 units/kW/day (about 123 units a month).

How many units does a 3 kW solar panel produce per day?

A 3 kW solar panel system produces about 11–16 units per day in India, about 12 units on average. It is less in the monsoon and more in summer.

How many units does a 10 kW solar system generate per day?

A 10 kW solar system generates about 37–53 units per day in India, about 41 units on average, or roughly 1,230 units a month.

How many units does a 3 kW solar system generate per month?

A 3 kW solar system generates about 330–480 units per month in India: about 480 in Rajasthan, about 390 in Mumbai and about 370 at the national average. Calculated as 3 kW × 5 peak sun hours × 0.82 performance ratio × 30 days ≈ 369 units.

What is peak sunshine hours and why does it matter?

Peak Sunshine Hours (PSH) is the number of hours per day when solar irradiance equals 1,000 W/m² (peak sun). India ranges from 4.5 PSH (northeast) to 6.5 PSH (Rajasthan). PSH directly multiplies your system output — a 3 kW system in Jodhpur (6.5 PSH) generates 40% more than the same system in Guwahati (4.5 PSH).

Does a solar system generate on cloudy or rainy days?

Yes — solar panels generate even on cloudy days, but at reduced output (20–40% of normal). During monsoon season (June–September), generation drops 30–50% compared to summer months. This is already factored into the annual estimates using monthly irradiance averages.

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