System size is sized to your average monthly consumption. Install cost is a planning estimate based on assumed 2026 market pricing (₹55,000–66,000/kW, declining with system size) — this is a modelled assumption, not a sourced live pricing feed, so treat it as a starting point rather than a quote. PM Surya Ghar central subsidy follows the official slab: ₹30,000/kW up to 2 kW, ₹18,000/kW for the third kW, capped at ₹78,000. State top-ups are modelled to scale proportionally with the same slab — this is our modelling assumption for how a flat state top-up applies to smaller systems, not a stated rule of any state's policy, so treat state top-up figures as indicative. The savings projection assumes any eligible surplus generation (up to 15% above your yearly consumption) offsets your electricity cost at the same rate as consumption you'd otherwise buy — in practice, net-metering settlement for exported units varies by DISCOM and may be lower than retail tariff. The projection also applies 3% annual tariff escalation, 0.6% annual panel degradation, ₹500/kW/year maintenance, and a one-time inverter replacement (₹3,500/kW) in year 12. The monthly bill-reduction figure shown above is before that annual maintenance deduction; the payback and 25-year figures are net of it. All figures are indicative planning estimates — get a site-specific quote from an MNRE-empanelled installer before deciding, and confirm current subsidy terms with your DISCOM.