Solar panels in Mumbai

Modelled output of a 6 kWp system at 35° facing south (towards the equator), from PVGIS climate data (PVGIS-ERA5, 2005 to 2023).

• Best month: January (970 kWh). Weakest: July (375 kWh), a 2.6x difference.
• January, March, December produce 32.2% of the year; June, July, August produce 15.1%.
• Year-to-year variation: about 203 kWh (2.3%, one standard deviation).
• Sunlight reaching the panels: 2,015 kWh per m² a year.

Rules set by the city or its region, on top of the national scheme. Each one was checked against the official source on the date shown.

• Maharashtra Electricity Regulatory Commission

  MERC net metering: year-end credits bought at generic tariff

  Under MERC's rooftop solar regulations (2019, amended 2023 and 2024), excess exported units carry forward bill to bill, and units still unadjusted at the end of each financial year are bought by the distribution licensee at the MERC-approved generic tariff for that year. The minimum system size is 1 kW.

  Source: Maharashtra Electricity Regulatory Commission, MERC (Grid Interactive Rooftop Renewable Energy Generating Systems) Regulations, 2019 (checked 2026-09-25)

• Maharashtra Electricity Regulatory Commission

  Online agreement replaces physical net metering agreement

  Since 30 June 2026, MERC directs all Maharashtra distribution licensees to accept the online application's digital agreement instead of a separate physical net metering agreement, for PM Surya Ghar and other rooftop solar applications.

  Source: Maharashtra Electricity Regulatory Commission, Practice Direction: Recognition of Digital Agreement for Rooftop Renewable Energy Generating Systems (30 June 2026) (checked 2026-09-25)

• Mumbai

  Tata Power is one of Mumbai's distribution licensees

  Mumbai has more than one electricity distribution licensee, and net metering is arranged with the licensee that supplies the home. Tata Power's Mumbai licence area runs from Colaba to Mira-Bhayander.

  Source: Tata Power Company Ltd., Tata Power Mumbai | Power Distribution Services (checked 2026-09-25)

Mumbai ranks 2 of 3 for yield among the cities we model in India, and 13 of 41 across every country on Solar Figures. Within one country the prices are the same, so a payback gap between these cities comes from sunshine alone.

Closest yield abroad: Naples (1,449 kWh per kWp), Rome (1,429 kWh per kWp), Brisbane (1,469 kWh per kWp).

Power you use yourself is worth the retail price (₹7.00 per kWh); power you export earns ₹7.00. So the share you use at home, by running appliances in daylight or adding a battery, changes the payback. The system cost stays the same in every row (a battery would add to it).

• Net system cost after incentives: ₹282,000 for 6 kWp.
• Incentive modelled: ₹78,000 (PM Surya Ghar (Rs 30,000/kW first 2 kW + Rs 18,000 for 3rd kW, cap Rs 78,000 at >=3 kW)).
• 25-year net savings at our default: ₹1,418,288.

At latitude 19.08°N, PVGIS finds the fixed tilt and direction that maximise yearly output. Our figures use a common 35° roof; the table shows what the optimum adds.

The optimum adds 1.2% a year over the standard roof in Mumbai. Most of a roof's value comes from its direction: a roof facing away from the equator loses far more than a few degrees of tilt.