Off-grid solar for a farm house
Lights, fans, a TV and a fridge in a farm house away from the line. Panels, battery bank and inverter, with the sun hours for your state.
- 3.57 kWh a day
- Sun hours from NASA POWER
- One day of battery for cloudy weather
In Chennai, Tamil Nadu (5.2 sun hours)
The daily load
Typical ratings and hours. The fridge is the BEE star-label figure for a 250 L 3-star frost-free model, about 0.67 kWh a day.
| Appliance | How many | Watts | Hours a day | Wh a day |
|---|---|---|---|---|
| LED bulb | 6 | 9 W | 6 | 324 |
| Ceiling fan | 3 | 75 W | 10 | 2250 |
| Television | 1 | 80 W | 4 | 320 |
| Refrigerator (250 L, 3 star) | 1 | 150 W | 4.5 | 675 |
| Total | 3569 Wh |
Size by state
Sun hours for one district in each state. Lithium needs fewer panels because it loses less energy charging and discharging.
| State | Sun hours | Panels (tubular) | Tubular bank | Panels (lithium) | Lithium bank |
|---|---|---|---|---|---|
| Andaman & Nicobar IslandsNorth And Middle Andaman | 5 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| Andhra PradeshKrishna | 5.1 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| Arunachal PradeshTawang | 3.8 | 2.2 kW (4 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| AssamKamrup Metro | 4.4 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| BiharPatna | 4.8 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| ChandigarhChandigarh | 5.2 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| ChhattisgarhRaipur | 5.2 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| Dadra & Nagar Haveli and Daman & DiuDaman | 5.3 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| DelhiNew Delhi | 4.9 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| GoaNorth Goa | 5.3 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| GujaratAhmadabad | 5.5 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| HaryanaGurugram | 4.9 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| Himachal PradeshShimla | 4.7 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| Jammu & KashmirSrinagar | 4.7 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| JharkhandRanchi | 4.7 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| KarnatakaBengaluru Urban | 5.5 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| KeralaThiruvananthapuram | 5.4 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| LadakhLeh Ladakh | 5.1 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| LakshadweepLakshadweep District | 5.3 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| Madhya PradeshBhopal | 5.2 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| MaharashtraMumbai | 5.3 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| ManipurChurachandpur | 4.6 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| MeghalayaSouth West Garo Hills | 4.3 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| MizoramMamit | 4.7 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| NagalandPhek | 4.3 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| OdishaKhordha | 4.8 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| PuducherryKaraikal | 5.4 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| PunjabLudhiana | 5 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| RajasthanJaipur | 5.4 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| SikkimSouth District | 4.1 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| Tamil NaduChennai | 5.2 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| TelanganaHyderabad | 5.4 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.1 kW (2 × 550 W) | 2 × 51.2 V 100 Ah |
| TripuraKhowai | 4.7 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| Uttar PradeshLucknow | 4.9 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| UttarakhandDehradun | 5 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
| West BengalKolkata | 4.6 | 1.65 kW (3 × 550 W) | 8 × 12 V 150 Ah | 1.65 kW (3 × 550 W) | 2 × 51.2 V 100 Ah |
Sized with the solarbatterybankcalc.com engine: panels at a 75% performance ratio (PM Surya Ghar guidelines), raised so the array refills the battery with a margin (1.25× for lead-acid, 1.10× for lithium); battery for one day of autonomy at 50% depth of discharge for tubular and 80% for lithium. Off-grid systems are not eligible for the PM Surya Ghar subsidy.
Off-grid questions
Can I get the PM Surya Ghar subsidy for off-grid solar?
No. The scheme’s guidelines limit the subsidy to grid-connected rooftop systems.
Why is the off-grid array bigger than for the same units on the grid?
Off-grid panels must run the load and refill the battery every day, through battery losses, with a margin so the battery reaches full charge. On the grid, net metering banks any shortfall.
What does one day of autonomy mean?
The battery is big enough to run one full day with no sun, only using its safe depth of discharge. For places with long monsoon spells, plan two days, or keep a generator or grid backup.