Rooftop Solar Cost in Nepal: System Size, Panels & Payback
Size a rooftop solar system in Nepal from monthly units and sun hours, then estimate panels, roof area, system cost, battery and simple payback.
GharNaksa Team
Construction tracking for Nepal
Rooftop solar in Nepal is sold as freedom from the bill and the inverter-hum of load-shedding. The honest starting point is still the monthly units on your NEA bill, the sun hours on your roof, and whether you need storage. Panel count is an output, not a shopping list.
Use the rooftop solar cost calculator to size kW from units and sun hours, then read panel count, roof area, system cost, optional battery and simple payback. Coordinate the roof with rainwater harvesting and waterproofing. The electrical side belongs with house wiring cost.
Size from the bill
- 1Read average monthly kWh (units) for a normal season, not the festival spike alone.
- 2Divide by days, then by peak sun hours for your location (often ~4–5.5 h as a planning band).
- 3Uplift for inverter and dirt losses (a simple 1.2–1.3 factor is common in planning tools).
- 4That kW is the array target. Panels = kW ÷ panel wattage.
- 5Roof area ≈ panel area plus walkway and setback from the parapet.
On-grid, hybrid and the battery question
- On-grid / net metering — cheapest per kW; savings depend on export rules and daytime use.
- Hybrid with battery — covers evening and outages; check usable kWh, not nameplate.
- Structure — rails, waterproof penetrations, wind on a valley ridge. Poor mounts leak.
- Inverter location — ventilation, shade, and a DB with spare ways.
- Warranty split — panels, inverter and installation are three different promises.
Simple payback = installed cost ÷ annual kWh saved × tariff. It ignores degradation, tariff hikes and cleaning. Treat it as a conversation starter with the installer, then put the quoted kW, brand and roof photos in GharNaksa so a future waterproofing contractor knows where not to drill.
Do this before the salesman arrives
- Twelve months of bills, or at least three seasons.
- A roof plan with tanks, dishes, and stair bulkhead marked.
- Whether the house wiring and earthing can take the inverter—see electrical wiring.
- A written split of supply, install, net-metering paperwork and after-sales.
Frequently asked questions
Quick answers
How many solar panels does a Nepal house need?
Divide the kW you need by the wattage of one panel. A 3 kW system using 550 W panels is about 6 panels and roughly 15–20 m² of roof including spacing. Size kW from monthly units and sun hours first; do not start from a round panel count.
What is a typical rooftop solar cost in Nepal?
On-grid systems are priced per kW installed (panels, inverter, structure, wiring, installation). Batteries can double the cheque for the same array. Use current installer quotes in the calculator—module and inverter prices move. Simple payback is system cost divided by annual bill savings, before any tariff change.
Do I need batteries if I have net metering?
Not for bill reduction if net metering is actually available and the house uses power while the sun is up—or can export. Batteries are for load-shedding, evening peaks, or sites with no export. Do not buy a lithium bank “just in case” without pricing the extra.
