Your electricity bill is high. Load shedding hits at the worst time. You want to go solar but have no idea how many panels, what inverter size, or how many batteries you actually need. Enter your appliances below and get a complete equipment list with verified 2026 market prices in your local currency.
✓Verified: NREL PVWatts — IEC 62109 — 2026 Market Data — May 2026
Peak load if all appliances run at once. The calculator applies realistic daily usage hours per appliance type to get accurate system size.
Step 3 — System Preferences
Reduces required battery size significantly
How this calculator sizes your system: System kW = Daily kWh ÷ Peak Sun Hours ÷ 0.80. The 0.80 efficiency derate covers real-world losses: inverter efficiency (96%), wiring resistance (97%), temperature derating (92%), and dust/soiling (95%). Inverter is sized to running load × 1.25. Battery uses actual DoD: 50% for tubular, 90% for lithium. These are the verified engineering formulas per NREL PVWatts and IEC 62109.
Recommended System Size
0 kW
Based on your appliances, daily usage hours and local peak sun
Installation & Labour
Panel fixing, inverter wiring, commissioning
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Transport & Miscellaneous (5%)
Delivery, contingency, small accessories
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💰 Total Estimated Cost
All-in installed price estimate
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Daily Usage Scenarios — Three System Sizes Compared
Oversize Scenario — 8 Hours Flat for Everything
Every appliance multiplied by 8 hours. Iron for 8hrs. Pump for 8hrs. This is what cheap online calculators give you. It produces an oversized system and inflated cost.
System
0 kW
Panels
0
Daily kWh
0
Est. Cost
0
Do not use this number. A pump running 8 hours means the tank fills 3x over. An iron running 8 hours means 16 shirts pressed. These are not realistic. The result above is shown only for comparison.
AC 8hrs. Fans 10hrs. Lights 5hrs. Fridge 24hrs at 35% duty. Pump 1.7hrs (5 starts x 20min). Iron 0.5hrs. Oven 2hrs. Router 24hrs. Based on IEA residential consumption data and Pakistan load studies.
System
0 kW
Panels
0
Daily kWh
0
Est. Cost
0
This is what the equipment report above is based on. Recommended for most households planning a complete home solar system.
Optimised Scenario — Energy-Smart Usage
AC 6hrs (supplement with fans). Washing machine in peak solar hours. Iron 20 minutes. No oven on battery. This is achievable with minor habit changes and gives you 15 to 20% smaller system for the same result.
System
0 kW
Panels
0
Daily kWh
0
Est. Cost
0
If you can shift heavy loads (washing, iron, oven) to 10am to 4pm solar peak hours and use fans alongside AC, this is your minimum viable system. Saves Rs.100,000 to Rs.200,000 on average.
Monthly Bill Saving
0
on electricity bill
Payback Period
-
estimated ROI
25-Year Net Saving
0
after system cost
⚠ Disclaimer: Equipment costs are estimates based on verified 2026 market research. Actual prices depend on your installer, equipment availability, local taxes, and roof complexity. Always get minimum 3 quotes from certified installers. Panel and inverter prices fluctuate with PKR/USD exchange rate. Last updated May 2026.
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Sources & Methodology
✓
Engineering formulas per NREL PVWatts and IEC 62109. Daily usage hours from IEA Residential Consumption Survey 2024. Equipment pricing from Pakistan solar market research, May 2026. Battery DoD values per LiFePO4 manufacturer datasheets and tubular battery lab tests.
Authoritative source for peak sun hours by location and the 80% system efficiency derate used in all calculations. System Size = Daily kWh / Sun Hours / 0.80 follows NREL's PVWatts methodology exactly.
IEA residential appliance usage hours data used to calibrate daily usage multipliers. AC 8hrs, fans 10hrs, lights 5hrs, fridge 24hrs at 35% duty, pump 1.67hrs daily average. These are not assumptions — they are published consumption averages.
Appliance wattage (2026 inverter appliances): Modern 1.5T inverter AC = 900–1,200W running (NOT 1,600W — that was the old non-inverter figure). Inverter fridge = 80–120W (duty cycle). Inverter fan = 28W BLDC, 75W standard.
⏱ Last reviewed: May 8, 2026
How Solar Panel System Size is Calculated — The Right Way
What Every Solar Salesman Tells You (And Why it Costs You Money)
Your electricity bill reaches Rs.25,000. A salesman visits. He adds up your appliances, multiplies everything by 8 hours, and quotes you a 12kW system for Rs.1.4 million. You get a second quote: also 12kW. A third: 10kW. They all seem similar so you go with the cheapest. What none of them told you: a properly calculated system for your actual usage is likely 6 to 8kW — and the difference is Rs.250,000 to Rs.400,000 in components you don't need.
The mistake is applying 8 hours to every appliance. Your water pump runs five times a day, 20 minutes each — 1 hour 40 minutes total, not 8. Your iron runs 30 minutes. Your oven, 2 hours maximum. Applying 8 hours to those three alone adds 8.4 kWh of fake daily consumption to your bill. At 5 peak sun hours that forces a 2.1kW addition to your system size. Multiply across all appliances and the inflation is 40 to 60% above what you actually need.
Worked Example First: Lahore Home, 2x 1.5T Inverter AC + 6 Fans + 10 LEDs + Fridge + TV
Step 1 — Calculate daily energy:
2x AC (1,050W each) x 8hrs = 16.8 kWh
6x fans (75W) x 10hrs = 4.5 kWh
10x LED (9W) x 5hrs = 0.45 kWh
1x fridge (100W) x 24hrs x 35% duty = 0.84 kWh
1x TV (80W) x 4hrs = 0.32 kWh
1x router (15W) x 24hrs = 0.36 kWh Daily total: 23.3 kWh
Step 2 — System size:
23.3 kWh ÷ 5.2 sun hrs ÷ 0.80 = 5.6 kW → round to 6 kW
Step 3 — Panel count:
6,000W ÷ 585W per panel = 10.3 → 11 panels of 585W
The Formula: System Size (kW) = Daily kWh ÷ Peak Sun Hours ÷ 0.80
The 0.80 efficiency factor is not a safety margin — it is the measured real-world output difference between rated panel power and actual AC electricity delivered to your appliances. It accounts for: inverter DC-to-AC conversion losses (~4%), DC cable resistance (~3%), temperature derating at 65°C panel surface (~8%), and dust/soiling losses (~5%). Skipping this factor means your system underperforms by 20% from day one and you never understand why.
Why Modern Inverter ACs Require Far Fewer Panels Than Older Calculations Show
The 1.5-ton AC wattage figure you find on most solar calculators — 1,600W to 1,800W — is the power draw of a non-inverter AC from 2015. A 2026 inverter AC compressor adjusts speed to maintain temperature. At 28°C ambient, a 1.5-ton inverter AC draws 900W to 1,200W running. In mild weather it runs at 600W. Only at peak summer load does it approach 1,300W. Using 1,600W overcalculates your panel requirement by 25 to 60%.
AC Size
Old Non-Inverter
2026 Inverter AC (actual)
Overestimate Using Old Figure
1 Ton
1,400W
700–900W
+55%
1.5 Ton
1,800W
900–1,200W
+50%
2 Ton
2,400W
1,300–1,700W
+41%
3 Ton
3,500W
2,000–2,600W
+35%
This single correction drops the recommended system size for a typical Pakistani home with two 1.5T ACs from 10kW (using old figures) to 6 to 7kW (using actual inverter AC wattage). That's Rs.300,000 to Rs.400,000 in panels and inverter capacity you don't need.
Peak Sun Hours in Your Country — Why the Same System Produces Different Energy
A 6kW system in Karachi with 6 peak sun hours generates 36 kWh per day. The same 6kW system in London with 3 peak sun hours generates 18 kWh per day. This is why a "correctly sized" system for one country produces half the expected output in another — and why any solar calculator that doesn't ask your location is guessing.
Peak sun hours are not daylight hours. They are the equivalent number of hours at full 1,000 W/m² irradiance. Lahore gets 14 hours of daylight in June but only 5 to 5.5 peak sun hours because morning and evening light is too weak for full panel output. Always design with winter values (15 to 20% lower than summer) to ensure adequate power year-round.
Country / City
Peak Sun Hrs (summer)
Peak Sun Hrs (design safe)
6kW Daily Output (safe)
Pakistan — Karachi
6.0–6.5
5.5
33 kWh
Pakistan — Lahore/Islamabad
5.5–6.0
5.0
30 kWh
Pakistan — Quetta/DGK
6.5–7.0
6.0
36 kWh
India — Central/Rajasthan
6.0–6.5
5.5
33 kWh
UAE / Gulf States
6.5–7.5
6.0
36 kWh
United Kingdom
3.5–4.5
2.8
17 kWh
Germany / Netherlands
4.0–5.0
3.2
19 kWh
Australia — Queensland
5.5–7.0
5.5
33 kWh
Solar System Sizes, Real Costs, and What Each System Actually Runs
Standard System Sizes in Pakistan — 2026 Installed Costs
These prices are for complete installed systems: Tier-1 panels (Longi or Jinko), hybrid inverter (Growatt or Solis), L2 mounting structure, DC/AC wiring with proper protection, and labor. Battery is not included. Prices from May 2026 wholesale market data.
System Size
Panels (585W)
Inverter
Daily Output (Lahore)
Installed Cost (PKR)
3 kW
6
3kW hybrid
~18 kWh
Rs.380,000–450,000
5 kW
9
5kW hybrid
~30 kWh
Rs.620,000–750,000
6 kW
11
6kW hybrid
~36 kWh
Rs.720,000–870,000
8 kW
14
8kW hybrid
~48 kWh
Rs.900,000–1,100,000
10 kW
18
10kW hybrid
~60 kWh
Rs.1,100,000–1,350,000
The 5kW system at 9 panels of 585W is the most popular residential choice in Pakistan in 2026. It covers a 5-marla home with one 1.5T AC, ceiling fans, lights, fridge and TV with enough headroom for guest loads. Moving to 6kW adds Rs.100,000 to Rs.150,000 but gives comfortable margin for a second small AC or water pump.
Tubular vs Lithium Battery — What the Numbers Actually Say
Most installers still push tubular because the Rs.40,000 to Rs.50,000 per unit price is easier to sell than Rs.140,000 to Rs.210,000 per lithium unit. But the math tells a different story once you factor in usable capacity and replacement cycles.
Parameter
Tubular Lead-Acid (200Ah)
Lithium LiFePO4 (100Ah)
Price per unit (PK, 2026)
Rs.40,000–50,000
Rs.140,000–210,000
Usable capacity (DoD)
50% — 100Ah effective
90% — 90Ah effective
Cycle life
400–600 cycles (2–3 years)
6,000+ cycles (10–15 years)
Maintenance
Monthly distilled water top-up
Zero maintenance
Weight per unit
~60 kg
~12–15 kg
10-year total spend (4 units)
Rs.600,000–800,000 (3 replacements)
Rs.560,000–840,000 (no replacements)
The break-even point is years 5 to 7 depending on how many load-shedding cycles you run per day. If you use the battery daily (Pakistan's typical 6 to 12 hours load shedding), lithium wins clearly on 10-year cost. If load shedding is rare in your area, tubular remains cheaper.
Battery sizing note: Tubular batteries are specified at 50% DoD because discharging below 50% accelerates sulfation and kills the battery in 6 to 12 months instead of 2 to 3 years. Lithium LiFePO4 can safely discharge to 90 to 95% capacity — which means a 100Ah lithium unit provides effectively 90Ah of usable storage vs only 100Ah usable from a 200Ah tubular unit. Two 100Ah lithium batteries replace three 200Ah tubular batteries in most real-world applications.
L2, L3 and Elevated Mounting — Which One Do You Actually Need
Standard quotes in Pakistan include L2 (flush/flat) mounting. You only pay extra for elevated when your roof physically requires it — but knowing in advance prevents the invoice shock.
L2 Standard: Panels mounted flush to rooftop at 10–15° tilt. Included in all standard quotes. Cost: Rs.2,500–3,500 per panel for structure and rails.
L3 Tilted Fixed: Panels set at 20–30° tilt for better winter performance. Adds Rs.1,500–2,500 per panel. Worth it in Lahore/Islamabad where winter sun angle is lower. Not needed in Karachi.
Elevated H-Beam: Steel H-beam columns raise panels 3–5 feet above roof. Required when water tanks, parapet walls, or satellite dishes cause shade on flat-mounted panels. Adds Rs.5,000–8,000 per panel. On a 10-panel system: Rs.50,000–80,000 extra that almost never appears in the initial quote.
⚠ Hidden costs that regularly appear on final invoices but not initial quotes: Elevated mounting (Rs.5,000–8,000/panel when tank or parapet blocks flat mount). Long DC cable runs — Rs.300–500 per metre for 6mm² cable if inverter is far from roof. DB box with AC/DC breakers and surge arrester: Rs.15,000–25,000. Earthing system: Rs.5,000–15,000. Net metering application fee: Rs.5,000–20,000 depending on utility. Always ask your installer to itemize all components before signing.
How to Choose the Right Solar System — What Your Result Means
Reading Your Calculator Result: What to Do Next
The system size this calculator gives you is an engineering estimate based on your real appliance load and local sun hours. It is accurate within 10 to 15% for most homes. The next step is comparing it to what installers quote. If an installer quotes you 30% more panels than this calculator recommends, you have three options: ask them to justify the extra capacity with a load calculation showing their numbers, accept the extra capacity as a future-proofing buffer for appliances you plan to add, or get a second quote.
If an installer quotes less than this calculator suggests, ask specifically which appliances they excluded from the calculation. Common exclusions: water pump (high wattage, inflates the quote), washing machine (intermittent), geyser (high wattage). These may or may not run on solar depending on your system design.
On-Grid vs Off-Grid vs Hybrid — The Choice That Determines Your Battery Requirement
System Type
What It Includes
Works During Load Shedding?
Best For
On-Grid
Panels + string inverter only
No
Areas with no load shedding, net metering available
Hybrid
Panels + hybrid inverter + optional battery
Yes (with battery)
Pakistan, India, Africa: standard choice for load shedding areas
Off-Grid
Panels + inverter + large battery bank
Yes (battery sized for full night)
Remote areas with no grid, farms, villages
When the Solar Sizing Formula Does Not Apply — Three Edge Cases
The formulas this calculator uses work accurately for most residential setups. Three situations require professional adjustment. First: significant roof shade from trees, water tanks, or adjacent buildings covering more than 20% of panel area reduces effective output by 15 to 30%. Add that percentage more panels to compensate, or install micro-inverters (which handle shade per-panel instead of at the string level). Second: in extreme heat zones like Multan and Karachi in July, panel surface temperature reaches 70 to 75°C, increasing temperature derating to 12 to 15%. The 0.80 efficiency factor used here includes a standard 8% temperature estimate. In extreme-heat locations use 0.75 instead. Third: three-phase commercial loads above 15kW require different inverter topology and must be sized by a certified solar engineer. This calculator is designed for single-phase residential systems up to 20kW.
Is Your Inverter Really Sized Correctly? The 1.25x Rule
The correct formula for inverter sizing is: Inverter kW = Peak simultaneous running load × 1.25. This 1.25 factor covers motor starting inrush current (not the full 3x surge — hybrid inverters have built-in surge protection rated to 2 to 3x nominal output) and gives a comfortable operating margin. A Growatt 5kW SPH inverter running at 4kW continuous load runs cooler, lasts longer, and handles occasional startup spikes without tripping.
What you should NOT do: size your inverter to the sum of every appliance's startup surge simultaneously. You won't start every AC, every pump, and the washing machine at the exact same second. The 1.25x running load formula is what certified solar engineers use in IEC 62109-compliant system design.
If your solar system trips when the AC starts: The inverter is either undersized (running at near-full load before the AC starts) or the battery is at low state of charge (limiting inverter output). Fix 1: check if other high-load appliances are running at AC start time and sequence the starts. Fix 2: add a soft-start capacitor to the AC compressor (Rs.5,000 to Rs.15,000) — reduces startup current by 60%. Fix 3: if the inverter consistently trips with a correctly calculated load, it may be undersized and needs replacement.
What a Good Solar Price Per Watt Looks Like in 2026
The only fair way to compare quotes is cost per installed watt: divide the total all-in quote by the system size in watts. In Pakistan in 2026, a well-priced Tier-1 hybrid system (Longi or Jinko panels, Growatt or Solis inverter, L2 structure, proper wiring) should cost Rs.95 to Rs.130 per installed watt. Below Rs.90/W means someone has cut corners on panel quality, inverter brand, or wiring protection. Above Rs.145/W means you are paying for brand premium (Huawei, SolarEdge) or the installer's margin is excessive.
Frequently Asked Questions
5 to 6 panels of 585W for a 1.5-ton inverter AC running 8 hours per day. A modern 2026 inverter AC draws 900 to 1,200W running — not the old 1,600W figure from non-inverter models. At 5 peak sun hours: (1,050W × 8hrs) ÷ 0.80 ÷ 5 = 2.1 kW for the AC alone. Add a full home load (fans, lights, fridge, TV) and the realistic total is 9 to 11 panels at 585W for a complete 5 to 6kW system.
9 panels of 585W (9 × 585 = 5,265W). With 540W panels it is 10. With 440W panels it is 12. The 585W panel is the current residential standard in Pakistan in 2026, priced at Rs.28 to Rs.35 per watt for Tier-1 Longi, Jinko, and Canadian Solar. A 5kW system installed (no battery) costs Rs.620,000 to Rs.750,000 in Lahore as of May 2026.
System Size (kW) = Daily Energy (kWh) ÷ Peak Sun Hours ÷ 0.80. The 0.80 efficiency derate covers inverter losses (4%), wiring losses (3%), temperature derating (8%), and soiling (5%). For a Lahore home using 23 kWh/day at 5.2 sun hours: 23 ÷ 5.2 ÷ 0.80 = 5.5 kW, rounded to 6 kW. Panel count: 6,000W ÷ 585W = 11 panels.
Inverter kW = Peak simultaneous running load (W) × 1.25 ÷ 1000. Add up all appliances that run at the same time, multiply by 1.25 for startup tolerance and derating margin. Modern hybrid inverters have built-in surge protection, so the old “size to startup surge” method overcalculates. Example: 2,100W (ACs) + 450W (fans) + 90W (LEDs) + 200W (other) = 2,840W × 1.25 = 3,550W → 5kW inverter (next standard size).
Battery Ah = (Load W × Backup Hours) ÷ (48V × DoD). Tubular DoD = 0.50, lithium = 0.90. Real example: 1,500W essential load (fans, lights, fridge) for 8 hours. Tubular: (1,500 × 8) ÷ (48 × 0.50) = 500Ah. At 200Ah per battery = 3 batteries (Rs.120,000–150,000). Lithium: (1,500 × 8) ÷ (48 × 0.90) = 278Ah. At 100Ah per unit = 3 units (Rs.420,000–630,000). Lithium costs 3x upfront but lasts 10x longer.
As of May 2026: Tier-1 monocrystalline (Longi HiMo 6, Jinko Tiger, Canadian) costs Rs.28 to Rs.35 per watt. N-Type premium (Longi HiMo X10, Jinko Neo) costs Rs.38 to Rs.43 per watt. Budget A-Grade (Astro Energy, RENA) costs Rs.24 to Rs.29 per watt. A popular 585W Tier-1 panel costs approximately Rs.16,500 to Rs.20,500 per unit. Prices fluctuate with the PKR/USD exchange rate by approximately 1 to 3% per week.
Lithium is better for homes with daily load shedding, tight roof space, and who prefer zero maintenance. Tubular is better for tight budgets and areas with occasional load shedding. Lithium LiFePO4 delivers 90% usable capacity vs 50% for tubular — effectively double the backup from similar-rated units. A 48V 100Ah lithium provides the same usable backup as a 48V 200Ah tubular battery, at roughly 2.5x the price per unit but with 10x the cycle life (6,000 cycles vs 500 to 600).
Three causes: (1) The inverter is running near its rated output already, and the AC startup current pushes it over limit. (2) Battery state of charge is low (below 20%), limiting inverter output. (3) Multiple high-load appliances started simultaneously. Fix in order: check if the pump or washing machine was running at AC start time and stagger starts. Add a soft-start capacitor to the AC (Rs.5,000 to Rs.15,000, reduces startup current by 60%). If problem persists, the inverter may be undersized and needs replacing.
Pakistan averages 4.5 to 6.5 peak sun hours depending on location. For conservative safe system design: Lahore and Islamabad: 5.0 to 5.5 hours. Karachi and Multan: 5.5 to 6.0 hours. Quetta and DG Khan: 6.0 to 6.5 hours. Always design using the lower figure, not the average, because winter months in Lahore can drop to 3.5 to 4.0 hours and you need the system to still meet your needs in December and January.
Rs.1,100,000 to Rs.1,350,000 all-in for a complete 10kW hybrid system with Tier-1 panels, hybrid inverter (Growatt 10kW or Solis 10kW), L2 mounting, DC/AC wiring, surge protection, and installation labor. This excludes batteries. Adding 4 × 200Ah tubular batteries for 8-hour essential backup: Rs.160,000 to Rs.200,000 more. A 10kW system generates 50 to 55 kWh per day in Lahore at 5 peak sun hours.
Top Tier-1 brands in Pakistan 2026: Longi Solar (HiMo 6 and HiMo X10), Jinko Solar (Tiger Neo N-Type), Canadian Solar (HiHero), JA Solar (Deep Blue), and Trina Solar. All carry IEC 61215 and TUV certification. Longi and Jinko are the most widely available with strong after-sales service networks. Longi HiMo X10 at Rs.38 to Rs.41/W and Jinko Neo at Rs.40 to Rs.43/W are the premium N-Type options. For Tier-1 value: JA Deep Blue at Rs.29 to Rs.33/W.
5 kW for most 5-marla homes consuming 400 to 600 units/month with one 1.5T AC. With 585W panels that is 9 panels. Installed cost Rs.620,000 to Rs.750,000 without battery. If you have two 1.5T ACs: 7 to 8kW system, 13 to 14 panels, Rs.860,000 to Rs.1,050,000. A simple rule from Pakistani solar engineers: 3 to 5 marla = 5kW, 5 to 8 marla = 8kW, 8 to 12 marla = 10kW. These are guidelines — use this calculator for a precise appliance-based calculation.
Yes, during daylight hours (approximately 8am to 6pm) with a hybrid or on-grid inverter. The inverter draws directly from solar panels with grid as backup when solar is insufficient. At night or during low-sun periods, the grid supplies power automatically. For running AC entirely off-grid overnight you need a battery bank sized to 8 to 12 hours of AC load, which is expensive. Most Pakistani homeowners run ACs from solar during the day and from the grid (or a smaller battery bank for essential loads) at night.
Use cost per installed watt: total quote ÷ system size in watts. Rs.95 to Rs.130/W in Pakistan (2026) is the fair range for a complete Tier-1 hybrid system. Below Rs.90/W: ask what has been cut (B-grade panels? budget inverter? no surge protection?). Above Rs.145/W: you are paying for premium brands (Huawei, SolarEdge) or excessive margin. Get minimum 3 quotes, all specifying the same panel brand and inverter model, so you are comparing like for like. The cheapest quote is not always the best value if it uses B-grade panels that degrade 40% faster.