First-Time Buyer's Guide: 7 Things to Check Before Installing Rooftop Solar (Gujarat, 2026)

Gujarat is India's leading rooftop solar state. With the central PM Surya Ghar subsidy of up to ₹78,000, collateral-free loans near 6.75%, and a realistic 3–5 year payback, rooftop solar is a strong investment — if you size it to your bill, use ALMM-listed DCR panels, and pick an MNRE-empanelled installer. This guide walks you through the seven checks every first-time buyer should make before signing anything.

Check 1: Roof Suitability & Shading

Check your roof physically before anything else.

• Area: Budget roughly 32 sq. ft. of shadow-free roof per panel (600 Wp / 0.6 kW), which works out to about 54 sq. ft. per kW. A 3 kW system (5 panels) needs about 160 sq. ft. Modern TOPCon 600 Wp panels keep the footprint compact.
• Orientation & tilt: Gujarat is in the Northern Hemisphere, so panels should face true south. For Ahmedabad (latitude ~23°N), optimal tilt is about 20–23°. On flat RCC terraces, installers commonly use 10–15° to balance generation, self-cleaning and wind load. East/west orientation loses roughly 10–18% annually but can be acceptable when the south face is shaded.
• Shading is critical: Even partial shade from a water tank, parapet, wall, chimney, tree, or neighbouring building cuts output disproportionately, because shading one panel drags down a whole string. Insist on a shadow-free area, or use microinverters/optimisers and elevated structures where shading is unavoidable.
• Roof type & condition: RCC flat roofs are ideal. Tin-shed/metal roofs need lightweight aluminium rails; old or weak asbestos roofs need careful load assessment. RCC roofs built after 1990 generally carry the extra ~35–45 kg/sqm dead load comfortably, but pre-1985 construction should be structurally assessed first. Confirm waterproofing — non-penetrating ballasted mounts avoid drilling and protect it.

Check 2: Sizing the System Correctly

Size to your electricity bill, not your roof or your neighbour's system.

• From your bill: Check your monthly units (kWh). In Gujarat a 1 kW system generates about 4–4.5 units/day (~1,400–1,500 units/year). So a 3 kW system produces about 12–15 units/day (~360–450/month, ~4,200–4,800/year).
• The PM Surya Ghar sweet spot: Per MNRE's consumption table — 0–150 units/month suits 1–2 kW; 150–300 units suits 2–3 kW; above 300 units suits 3 kW+. A 3 kW system covering ~300 units/month is the "sweet spot" for a typical home and unlocks the full ₹78,000 subsidy.
• Don't over-size: Gujarat credits surplus exported power at only ₹2.25/unit (first 5 years), far below the ~₹7–8/unit you save by self-consuming. Over-sizing wastes roof and subsidy headroom. Also check your sanctioned load — your system should align with it.

Check 3: Panel & Equipment Quality

• ALMM panels: Panels must be on MNRE's Approved List of Models and Manufacturers (List-I) to qualify for subsidy. Verify the exact model number, not just the brand.
• DCR panels: Subsidised residential systems require Domestic Content Requirement modules (Indian-made cells AND modules). Non-DCR panels disqualify you from the entire ₹78,000 subsidy. As of June 2026, there is no blanket extension of ALMM List-II beyond 1 June 2026 — List-I modules must use domestically-made cells.
• BIS certification: All modules sold in India must carry BIS certification (IS 14086) under the 2022 Quality Control Order.
• TOPCon vs Mono PERC: TOPCon is the newer technology now mainstream in 2026; it has a better temperature coefficient (about –0.29 to –0.31%/°C vs –0.34 to –0.37%/°C for Mono PERC), so it loses less output in Gujarat's heat, at a 5–15% price premium.
• Inverter: A string inverter is standard and cost-effective for clean, unshaded roofs; microinverters cost more but suit shaded or multi-direction roofs and allow panel-level monitoring. The inverter is usually slightly smaller than panel capacity (a DC-to-AC ratio of about 1.15–1.25 is normal and intentional).
• Balance of System (BOS): Don't ignore it. Use a hot-dip galvanised steel structure (RCC roofs) or aluminium (tin sheds), wind-load rated per IS 875 — coastal Gujarat needs higher ratings than inland. Quality DC/AC cables, proper earthing, lightning protection, and ACDB/DCDB boxes are essential for safety and longevity.

Check 4: Warranties & What They Really Mean

• Panels: Expect a product (defect) warranty of 10–12 years on standard panels (premium lines now up to 25 years), plus a separate performance warranty of 25–30 years guaranteeing roughly 80–87% output at year 25.
• Inverter: Typically 5–10 years (string), sometimes extendable; microinverters often 25 years. Budget for one inverter replacement over the system's life.
• Workmanship: Get a written installation/workmanship warranty from the EPC company itself.
• Get it in writing and clarify who honours each warranty — the manufacturer handles panel/inverter defects, the installer handles workmanship. Note that most manufacturer warranties exclude labour/transport cost of replacement.

Check 5: Installer / EPC Vendor Selection

• Empanelment matters: Subsidy is only paid if you use an MNRE-empanelled vendor registered with your DISCOM. Verify the vendor on pmsuryaghar.gov.in before signing or paying.
• Red flags: Quotes far below market; reluctance to put panel models, ALMM/DCR status and warranties in writing; no past project references; no after-sales/O&M support; pushing non-ALMM or non-DCR panels.
• Due diligence: Prefer installers with local Gujarat presence, a track record of completed installations, genuine reviews, and a proper written contract.
• Questions to ask: Are you empanelled with my DISCOM? What is the exact panel make/model and is it in ALMM List-I + DCR? Who handles net-metering paperwork? What is your workmanship warranty and AMC? Can I see two local installations?

Check 6: Subsidy, Net Metering & Approvals

• Central subsidy (verified, current 2026): ₹30,000/kW for the first 2 kW, ₹18,000 for the 3rd kW, capped at ₹78,000 for systems of 3 kW and above. Confirmed on MNRE's National Portal (pmsuryaghar.gov.in, last updated 25 May 2026). Credited via Direct Benefit Transfer to your Aadhaar-linked bank account, normally within 30 days of DISCOM approval.
• Application flow: Register on pmsuryaghar.gov.in → DISCOM feasibility approval → install → net-meter request → inspection & commissioning → subsidy DBT. Apply only via the national portal.
• Net metering (GERC): Required from your DISCOM. A bidirectional meter records import and export; the DISCOM supplies/installs the meter but you bear the cost, and a check meter is mandatory above 20 kW. Per GERC Notification No. 02 of 2022 (Third Amendment), surplus from self-owned systems and SURYA Gujarat consumers is purchased at ₹2.25/unit for the first 5 years from commissioning, then at 75% of the simple average of tariff discovered by GUVNL for non-park based solar.
• Gujarat DISCOMs: UGVCL (North/Ahmedabad rural, Gandhinagar), MGVCL (Central/Vadodara), DGVCL (South/Surat), PGVCL (Saurashtra/Rajkot), and Torrent Power (Ahmedabad, Surat, Gandhinagar city).
• State subsidy: There is no additional Gujarat state cash subsidy on top of the central one in 2026. The official Gujarat Power R&D Cell records that the old SURYA-Gujarat scheme offered "40% [state subsidy] for Solar Rooftop Systems up to 3 kW and 20% beyond 3 kW up to 10 kW," with coverage planned only "up to year 2021–22." Any claim of a ₹10,000–40,000 state top-up on installer blogs is unverified and should be flagged.
• Documents: Latest electricity bill, Aadhaar, Aadhaar-linked bank account (name must match exactly for DBT), property ownership proof, and a passport photo.

Check 7: Cost, Financing & Payback

• Installed cost: Roughly ₹50,000–65,000 per kW for small residential systems before subsidy; per-kW cost falls for larger systems. A 3 kW system runs about ₹1.65–1.96 lakh before subsidy.
• Net cost after central subsidy (typical): 1 kW = ₹25,000–35,000; 2 kW = ₹50,000–60,000; 3 kW = ₹90,000–1,18,000.
• Savings: A 3 kW system generating ~4,200–4,800 units/year saves roughly ₹30,000–40,000/year at typical higher-slab tariffs (effective ~₹7–8/unit all-in), i.e. about ₹2,500–3,300/month.
• Payback: Realistically 3–5 years in Gujarat. After payback, roughly 20 years of largely free power.
• Financing: Under PM Surya Ghar, 12 public-sector banks offer collateral-free loans up to ₹2 lakh for systems up to 3 kW, with interest rates around 6.75–7% per year and tenures up to 10 years. The subsidy is credited against the loan principal once it is received — no pre-payment penalty typically applies.
• Hidden costs to watch: Net-meter charges, elevated/high-raised mounting structures (which can sharply increase structure cost), civil work, longer cable runs, and AMC charges.

After-Sales, O&M & Documentation

Gujarat is dusty, so cleaning matters: clean panels every 15–20 days in dusty conditions (every 30 days minimum), plus after dust storms and post-monsoon. Use only soft cloths. Never use a high-pressure washer. Use the inverter's monitoring app to spot output drops. Consider an Annual Maintenance Contract (AMC) — look for one that includes your commissioning certificate, net-meter proof, warranty cards, and app setup at handover.

Common First-Time Mistakes to Avoid

• Accepting non-DCR/non-ALMM panels — instant disqualification from subsidy.
• Buying on price alone; ignoring shading and roof quality.
• Over-sizing for export; ignoring your sanctioned load.
• Signing without documentation in writing.
• Financing before subsidy approval (you may need to resize).

Figures (subsidy amounts, costs, savings) are indicative and based on verified government sources and publicly available 2026 data. Prices and policy may change — always confirm current status on official MNRE/DISCOM channels. Actual savings depend on your tariff slab, consumption pattern, roof orientation, shading, and maintenance.