In short: in Thiruvananthapuram, 1 kW of solar makes about 120 units a month. Divide your monthly units by 120 to get the system size in kW.
Step 1: find your monthly units
KSEB bills domestic consumers every two months. Take the units consumed on your bill and divide by 2. For a better estimate, average the last six bills, because usage rises in the hot months.
Step 2: divide by 120
A well-installed system here averages about 4 units per kW per day, or roughly 120 units per kW per month across the year.
| Bimonthly units on bill | Monthly units | Suggested size | Roof space |
|---|---|---|---|
| 240 | 120 | 1 kW | ~90 sq ft |
| 480 | 240 | 2 kW | ~180 sq ft |
| 720 | 360 | 3 kW | ~270 sq ft |
| 1,200 | 600 | 5 kW | ~450 sq ft |
Step 3: check your roof and plans
Shade from trees, water tanks or nearby buildings reduces output, so the roof survey matters. If you plan to add an AC, induction cooking or an EV, size up now. Adding panels later costs more.
Want a quick number? Try the savings calculator on our home page, then book a free site survey for an exact design.