Electricity Bill + Solar Savings Calculator (Nepal)
Estimate your monthly NEA electricity bill from a list of household appliances, see which appliances cost the most to run, and estimate how much rooftop solar would save.
Appliance schedule
Tariff & meter
Rooftop solar (optional)
Biggest drain: Refrigerator — 32.14% of your monthly units. A suggested 2.93 kWp solar array would offset roughly all of it.
Per-appliance running cost
| Appliance | Watts | Qty | Hrs/day | Units/mo | Rs/mo | Share % |
|---|---|---|---|---|---|---|
| Refrigerator | 150 | 1 | 24 | 108 | 1174 | 32.1 |
| Induction cooktop | 1800 | 1 | 1.5 | 81 | 880 | 24.1 |
| Electric geyser | 2000 | 1 | 1 | 60 | 652 | 17.9 |
| Ceiling fan | 60 | 3 | 8 | 43.2 | 469 | 12.9 |
| Rice cooker | 700 | 1 | 1 | 21 | 228 | 6.2 |
| LED TV | 80 | 1 | 5 | 12 | 130 | 3.6 |
| LED bulb | 9 | 8 | 5 | 10.8 | 117 | 3.2 |
Estimate only. NEA domestic single-phase schedule (widely-published estimate); ERC revises rates each fiscal year and low-usage VAT concessions vary — verify the slabs, service charge, and VAT against your latest NEA bill and override where they differ.
How this works
Each appliance's monthly units are its wattage × quantity × hours per day × 30 days, divided by 1000. The NEA energy charge is billed telescopically — each consumption slab is charged at its own rate and summed — then the fixed meter service charge and VAT are added.
monthlyUnits = Σ (W × qty × hrs/day × 30) / 1000
energy = Σ over slabs (units in slab × slab rate)
bill = energy + serviceCharge + VAT
netUnits = max(0, monthlyUnits − solarUnits)
savings = bill(monthlyUnits) − bill(netUnits)
suggestedPV = (units/30) / peakSunHours / 0.85Set a custom rate per unit to bypass the slabs with a flat rate, or edit the VAT % and meter capacity to reproduce the exact figures on your bill.
Worked example
A home using 229.5 units/month on a 15 A single-phase meter (service charge Rs 50), 13% VAT:
- Energy (telescopic) =
20×3 + 10×6.5 + 20×8 + 50×9.5 + 50×9.5 + 79.5×10 = Rs 2,030 - + Service
Rs 50= Rs 2,080 - + VAT 13%
Rs 270.40= Rs 2,350 total - Blended rate ≈ Rs 10.24 / unit
Sources
- NEA domestic single-phase schedule (widely-published estimate); ERC revises rates each fiscal year and low-usage VAT concessions vary — verify the slabs, service charge, and VAT against your latest NEA bill and override where they differ.
FAQ
How is the NEA electricity bill calculated?
NEA bills domestic consumers on a telescopic slab system: the units you use are split across consumption bands (0–20, 21–30, 31–50, 51–100, and so on), and each band is charged at its own rate — not the whole month at a single rate. The energy charge is the sum across bands. On top of that you pay a fixed monthly service (demand) charge set by your meter's sanctioned ampere capacity, and VAT. This tool sums wattage × quantity × hours-per-day × 30 for every appliance to get your monthly units, then applies exactly that slab-plus-service-plus-VAT structure.
Are the tariff rates in this tool official and current?
Treat them as a well-published estimate, not an official figure. NEA's retail tariff is set by the Electricity Regulatory Commission (ERC) and revised roughly every fiscal year, and secondary sources disagree on some mid-band rates and on how VAT is applied to low-usage months. That is why every rate here is overridable — pick the meter capacity that matches your connection, edit the VAT percentage, or enter a flat custom rate per unit to reproduce the exact figures printed on your own NEA bill. Always verify against a recent bill before relying on the number.
Which appliances use the most electricity?
Heating appliances dominate: an electric geyser (2000–3000 W), induction cooktop (1800–2200 W), electric heater, and immersion rod each pull more in one hour than a fridge does in most of a day. The per-appliance table ranks your list by monthly units so the biggest drains are obvious. Because the top NEA slabs are the most expensive, trimming an hour off the geyser or shifting to a solar water heater often saves more than any lighting change — the calculator's blended effective rate shows what each extra unit truly costs you.
How does the solar savings estimate work?
Enter the monthly units your rooftop solar generates (or plans to) in the solar offset field. The tool subtracts that from your consumption, re-runs the full slab-plus-service-plus-VAT bill on the remaining units, and reports the difference as your monthly and annual saving. Because it removes units from the most expensive top slabs first, the saving per solar unit is usually higher than your average rate. Enter the system's installed cost to get a simple payback period, and see the suggested kWp array size that would offset roughly all your usage.
What meter capacity should I choose?
Most Nepali homes have a single-phase 5 A or 15 A connection; larger homes with heavy loads use 30 A, 60 A, or a three-phase supply. The ampere rating only changes the fixed monthly service charge here, not the per-unit energy rate — but the service charge is also your effective monthly minimum, so it matters most in low-usage months. If you are unsure, the sanctioned capacity is printed on your NEA bill and on the meter itself.
Does Nepal allow net metering to sell solar back to NEA?
NEA operates a net-metering scheme for grid-tied rooftop solar where eligible consumers can export surplus generation and offset it against imported units, subject to system-size limits and NEA approval. This calculator models the simpler and more common case — solar reducing the units you draw from the grid — which captures the bulk of the saving for most homes. If you are on a net-metering agreement, enter your net monthly import as the consumption and treat exports separately, since NEA's settlement terms and any buy-back rate vary by agreement.
Why is the estimate slightly different from my actual bill?
A few reasons: real appliances rarely run at their nameplate wattage for exactly the hours you enter (a fridge cycles on and off, a geyser's thermostat cuts in and out), billing months are 28–31 days rather than a flat 30, meter-reading dates shift, and NEA occasionally applies rebates or dues adjustments. Use rated wattages and honest average hours for the best estimate, then fine-tune the VAT percentage or set a custom rate per unit until the headline figure matches your latest bill.