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Solar

How to pick a solar vendor without getting scammed

Pakistan has ~1,200 solar installers and only ~180 are AEDB-certified. Here's how to filter them in 15 minutes — brands, BOM, red flags, and the 12 questions that reveal the pros from the pretenders.

The 12 questions that filter out 90% of vendors

  1. Show me your AEDB Category A/B licence and let me verify the number on aedb.org right now.
  2. Which specific panel brand + model + wattage + tier are you quoting? (Answer must include tier-1/2/3 rating.)
  3. Which inverter model, and what's its warranty period in writing?
  4. Is the inverter on the current NEPRA-approved list? Show me the exact page.
  5. What structural mounting are you using — clamps, ballast, or drilled? Who signs the structural certificate?
  6. How many AC and DC isolators are in the BOM? Where are they placed?
  7. Do you install DC + AC surge protection devices (SPDs)?
  8. What's the earthing arrangement? Show me the resistance target (should be < 5 Ω).
  9. What's the written performance guarantee for year-1 output?
  10. What's the workmanship warranty period — 1 year, 5 year, or 10 year?
  11. Who handles the DISCO net-metering submission and how many days after commissioning?
  12. What's included in Annual Maintenance — panel cleaning, inverter firmware, cable inspection? For how many years free?

If a vendor stumbles on any of Q1–Q4, walk away. Q5–Q12 separate professionals from generalists — you want at least 10/12 clean answers in writing before signing.

Bill of materials — what must be there

ComponentMinimum spec
PanelsTier-1 mono PERC or TOPCon, 550–600 W, 25-year linear warranty
InverterOn AEDB approved list, string type for <10 kW, MPPT ≥ 2, IP65
MountingAluminium rail + hot-dip galvanised clamps (never MS angle iron)
DC cabling4 mm² solar-rated, MC4 connectors, no household wire
AC cabling6–10 mm² copper, XLPE insulated, correct polarity marking
DC isolatorBetween array and inverter, IP65, lockable
AC isolatorBetween inverter and main panel, visible and accessible
DC SPD + AC SPDType 2, non-negotiable in Pakistan's monsoon climate
EarthingDedicated earth pit, ≤ 5 Ω resistance, tested and certified
MonitoringWi-Fi dongle + live app (Huawei FusionSolar, Growatt ShinePhone, etc.)

10 red flags

  • Quote missing panel wattage or brand — you'll be shipped whatever's cheapest that week.
  • 'Bifacial free' upsell — bifacial gives < 5% extra unless you have a white roof.
  • Verbal warranty only — if it's not in the invoice, it doesn't exist.
  • Deposits > 30% before delivery — 20–30% is standard, higher is a cashflow scam.
  • No mention of DC/AC isolators or SPDs in the BOM.
  • Refuses to install a Wi-Fi monitoring dongle 'because it needs internet' — that's your only fault-detection tool.
  • Promises to 'take care of' the DISCO officer — you're funding a bribe, not an approval.
  • Full payment demanded before DISCO commissioning — pay ≤ 90% before commissioning, hold 10% for 30 days post-commissioning.
  • Vendor won't put their CNIC + address on the invoice — you'll never trace them for warranty.
  • GST invoice not offered — you're losing tax-adjustment rights and it's likely off-books.

Payment schedule that protects you

  1. 20–30% on signing (locks equipment procurement).
  2. 40–50% on delivery of panels + inverter to site (verify serials before releasing).
  3. 20% on installation completion + earth-pit test passed.
  4. 10% withheld until DISCO commissions the bi-directional meter and system goes live. This is your only leverage.

Get a GST invoice at every stage. Total invoice value should match the quote to the rupee — any "extras" surfaced mid-installation are pure profit-taking, negotiate hard.

Frequently asked questions

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