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Data changelog & verification log
Stale figures are the number-one way a solar calculator loses trust. So we date every subsidy, tax-credit and tariff we build in, check them against the official source, and log every change here. If a scheme changes and we haven't caught it yet, this page tells you exactly how current each number is.
Verified in the last 6 months
Due for re-check (6–12 months)
Needs update (12 months+)
| Scheme / figure | Country | Last verified | Status | Official source |
|---|---|---|---|---|
| Federal Solar Tax Credit (ITC)+ state net-metering rules | USA | 10 Nov 2026 | Fresh | USA calculator |
| NEM 3.0 Net Billing Tariffexport rates & battery payback | USA (California) | 10 Nov 2026 | Fresh | NEM 3.0 calculator |
| PM Surya Ghar Muft Bijli Yojanarooftop subsidy ₹30,000–₹78,000 (₹85,800 special-category) | India | 10 Nov 2026 | Fresh | India calculator |
| Net metering + subsidy (on-grid)banking & export rules | India | 20 Jul 2026 | Fresh | On-grid India calculator |
| PM Surya Ghar loan (7% collateral-free)tenure & EMI terms | India | 10 Nov 2026 | Fresh | Solar loan EMI calculator |
| PM-KUSUM Component-Bfarmer pump subsidy split | India | 10 Nov 2026 | Fresh | KUSUM pump calculator |
| Accelerated depreciation (40%) & GSTcommercial / C&I ROI | India | 20 Jul 2026 | Fresh | Commercial calculator |
| STC rebateSmall-scale Technology Certificates | Australia | 10 Nov 2026 | Fresh | Australia calculator |
| EEG Einspeisevergütungfeed-in tariff & self-consumption | Germany | 10 Nov 2026 | Fresh | Germany calculator |
| NEPRA net billingbuyback & slab rates | Pakistan | 10 Nov 2026 | Fresh | Pakistan calculator |
| NEPRA Prosumer Regulations 2026SRO 251(I)/2026 | Pakistan | 10 Nov 2026 | Fresh | NEPRA net billing calculator |
| Smart Export Guarantee (SEG)per-kWh export rates | UK | 10 Nov 2026 | Fresh | UK calculator |
| Residential incentives & Eskom tariffsload-shedding backup context | South Africa | 10 Nov 2026 | Fresh | South Africa calculator |
Why this page exists. Government solar schemes change by notification, often with little warning. The most volatile figures — the US federal credit, California NEM 3.0, the UK SEG and Pakistan's NEPRA rates — should always be re-confirmed against the official source before you make a purchase decision. Each calculator also lets you edit every rate to match your own bill, so a figure that's shifted since our last check never traps you.
Recent updates
- 11 Nov 2026 — The region and currency selector now appears in the header of every page, not just the homepage. On phones it sits at the top of the menu. Your choice is remembered across pages; calculators priced in one fixed currency (Indian states, UK and Australian pages) keep their own currency.
- 11 Nov 2026 — Carbon offset calculator: the grid button labelled "US ~0.37 / UK ~0.21" actually used 0.23 kg CO₂/kWh. It is now two buttons with official figures: US 0.35 (EPA eGRID2023) and UK 0.13 (DESNZ 2026 conversion factors).
- 11 Nov 2026 — Solar loan EMI calculator: the monthly payment after you prepay the PM Surya Ghar subsidy now subtracts the two EMIs already paid before the subsidy arrives (it was about 6% too high, ₹1,375 instead of ₹1,297 a month on the default ₹1,65,000 loan). Added a worked "Quick answer" to 34 more calculators.
- 10 Nov 2026 — Calculator accuracy pass: every calculator's formulas were checked against an independent model with randomised inputs. Corrected: Australian STC deeming period (5 years for 2026, per the Clean Energy Regulator; was 4); PM-KUSUM central and state subsidy now stop at 7.5 HP (15 HP in special-category states), and diesel use is 0.25 L per HP per hour (was 0.9); Germany EEG feed-in now includes the 40–100 kWp band (5.44 ct); the US state list uses EIA residential prices (January–August 2026) and PVGIS output per kW instead of raw sun hours; inverter sizing no longer treats a space heater or coffee machine as a motor; run-time displays can no longer show "60 min".
- 10 Nov 2026 — Re-verified 11 schemes against official sources, added a Sources list and review date to every guide, and corrected: PM Surya Ghar special-category CFA (₹33,000/kW, ₹19,800 for the 3rd kW, cap ₹85,800) on 14 state/UT calculators; Pakistan buyback now the NEPRA energy purchase price (₨8.13/unit Apr–Jun 2026, was ~₨11) with the 25 kW fee exemption; Germany EEG rates for Aug 2026–Jan 2027; New Jersey SREC-II $77/MWh; UK price cap Oct–Dec 2026 (26.32p/kWh); Australia battery STC factor 6.8 with size tapering; Eskom tariffs (8.76% Apr 2026, 9.01% municipal Jul 2026).
- 20 Jul 2026 — Full quarterly re-verification of all 13 country schemes against their official portals. No breaking changes since the last review.
- Ongoing — Every country tool now carries an on-page "Verified" date so you can see how current its figures are without leaving the calculator.
Spotted a figure that's out of date? Tell us at contactus@prosolarcalc.com and we'll verify and log it here.