Rooftop solar planner
Roof 40 m² and sanctioned load 5.00 kW allow up to 4 kWp. Net metering with banking, 0.040 yearly tariff escalation. Change assumptions
Recommended size4 kWphighest 25-year NPV within limits
Payback2.8 yearsafter subsidy of Rs 78,000
IRR38.4%25 years
NPVRs 852,921at 8% discount rate
Size options
| kWp | Capex (Rs) | Subsidy (Rs) | Year-1 saving (Rs) | Payback | IRR | 25-yr NPV (Rs) | |
|---|---|---|---|---|---|---|---|
| 1 | 70,000 | 30,000 | 26,746 | 1.5 yr | 68.7% | 342,768 | view |
| 2 | 140,000 | 60,000 | 49,076 | 1.7 yr | 63.3% | 626,147 | view |
| 3 | 210,000 | 78,000 | 63,983 | 2.1 yr | 50.7% | 797,197 | view |
| 4 | 280,000 | 78,000 | 72,512 | 2.8 yr | 38.4% | 852,921 | view |
NPV by system size (Rs)
Cumulative cash flow, 4 kWp (Rs, by year)
4 kWp: monthly consumption vs generation (units)
ConsumptionGeneration
Generates 6356 units in year 1, of which 33% is used directly and the rest exported. Year-1 bill saving Rs 72,512.
| Month | Consumption | Generation | Used directly | Exported | Billed units | Bill without (Rs) | Bill with (Rs) |
|---|---|---|---|---|---|---|---|
| Jan | 377 | 570 | 151 | 420 | 0 | 4766 | 156 |
| Feb | 346 | 560 | 138 | 422 | 0 | 4401 | 141 |
| Mar | 486 | 657 | 194 | 463 | 0 | 6704 | 156 |
| Apr | 563 | 636 | 225 | 411 | 0 | 8261 | 151 |
| May | 576 | 620 | 230 | 390 | 0 | 8431 | 156 |
| Jun | 488 | 432 | 195 | 237 | 0 | 6791 | 151 |
| Jul | 413 | 384 | 165 | 219 | 0 | 5403 | 156 |
| Aug | 497 | 409 | 199 | 211 | 53 | 6889 | 532 |
| Sep | 404 | 480 | 161 | 319 | 0 | 5305 | 151 |
| Oct | 384 | 546 | 153 | 392 | 0 | 4890 | 156 |
| Nov | 355 | 528 | 142 | 386 | 0 | 4447 | 151 |
| Dec | 392 | 533 | 157 | 376 | 0 | 5040 | 156 |