Solar Savings Calculator India 2026

1. System size and peak sun hours

Generation depends on your system's kW capacity and how many peak sun hours your region gets — typically 4.5-5.8 hours/day across India, higher in Rajasthan and Gujarat, lower in the Northeast and coastal Kerala.

2. System efficiency and losses

Real-world output is lower than the theoretical maximum due to inverter conversion losses, wiring losses, dust, and panel temperature effects — typically modeled at around 75-80% overall system efficiency.

3. Self-consumption vs export

Savings are capped by how much of your generation you actually use or can export under net metering — a system oversized relative to your usage generates less proportional savings unless your state offers a good export rate.

4. Subsidy and net cost

Payback period is calculated on your net cost after the PM Surya Ghar subsidy is applied, not the sticker price — this is why applying for the subsidy correctly matters as much as choosing the right installer.

Net meter and DISCOM charges

Bi-directional net meter installation and DISCOM processing fees typically add ₹3,000-₹8,000 depending on your state and system size, on top of the panel and inverter cost.

Structural and roof work

Older roofs may need reinforcement or waterproofing before panel mounting — an inspection cost worth doing upfront rather than discovering mid-installation.

Annual cleaning and inspection

A basic cleaning and inspection contract costs ₹2,000-₹4,000/year. Dusty panels can lose 15-25% output in Indian conditions, so skipping this quietly reduces your savings.

Inverter replacement

String inverters typically need replacement once in the panel's 25-year lifespan, at roughly ₹15,000-₹40,000 depending on system size — worth factoring into long-term ROI calculations.

Bank & NBFC Solar Loans

Several public and private banks, along with NBFCs, offer dedicated rooftop solar loans, often at rates comparable to or lower than personal loans, since the asset itself secures part of the risk. Tenures commonly range from 3–10 years.

EMI That's Lower Than Your Bill Savings

A well-structured loan on a rightsized system often has an EMI close to or below your monthly bill savings — meaning your cash flow can improve from month one, even before the loan is paid off, rather than waiting years for a lump-sum payback.

PM Surya Ghar Collateral-Free Loan Scheme

Under the PM Surya Ghar Muft Bijli Yojana, the scheme framework includes provision for low-interest, collateral-free loans for residential rooftop systems up to a defined capacity, on top of the direct capital subsidy — check current bank empanelment and rates on the official portal.

Zero-Down / RESCO Model

Some installers offer a Renewable Energy Service Company (RESCO) model where a third party owns and maintains the system on your roof, and you simply pay a lower per-unit rate than your DISCOM tariff — no upfront cost, but you don't own the system or capture the full long-term savings.

A typical EV commuting 40–50 km a day needs roughly 6–8 kWh, well within what a mid-sized rooftop system generates during daylight hours. Scheduling your EV to charge between 10am and 3pm — when solar output peaks — lets you consume your own generation directly instead of exporting it at a lower rate and buying grid power back at night.

Compared to charging entirely off the grid at ₹7–₹8/unit, self-consumed solar charging has a marginal cost close to zero once the system is paid off, effectively stacking your EV's already-low running cost on top of a second layer of near-free electricity.

If you're planning both a solar install and an EV purchase, it's worth sizing your solar system 1–2 kW larger than your current household needs alone would suggest, so the extra capacity is ready for EV charging from day one rather than needing a costly system expansion later.

Panel Performance Warranty (typically 25 years)

Guarantees a minimum output level over time — commonly around 80–85% of rated output by year 25 — not that the panel will fail before then. This is a degradation guarantee, separate from a manufacturing defect warranty.

Panel Product/Defect Warranty (typically 10–12 years)

Covers manufacturing defects specifically — a different, usually shorter, window than the performance warranty above. Always ask installers to clarify which number they're quoting.

Inverter Warranty (typically 5–10 years)

Inverters have moving/electronic components with a shorter lifespan than panels — many buyers extend this via a paid extended warranty, since a replacement inverter mid-life is one of the larger unplanned costs in solar ownership.

Installation & Workmanship Warranty

Separate from equipment warranties, this covers the installer's own work (mounting, wiring, waterproofing) — get this in writing since it's the most commonly disputed warranty type.

India's grid electricity still comes substantially from coal, and each unit (kWh) drawn from that mix carries an associated CO₂ footprint. A 3 kW rooftop solar system generating roughly 4,300–5,400 kWh per year displaces that much grid electricity, avoiding approximately 2.5 tonnes of CO₂ emissions annually — a figure commonly compared to the annual carbon absorption of over 100 mature trees.

Over a 25-year system life, that adds up to roughly 60+ tonnes of avoided CO₂ for a single mid-sized home — for perspective, that's in the same range as taking a petrol car off the road for several years of typical driving.

As India's grid itself adds more renewable capacity over time, the marginal emissions avoided by displacing grid power will gradually shift too — but for the foreseeable future, rooftop solar remains one of the most direct, measurable ways an individual household can cut its carbon footprint.

Wind & Cyclone Resistance

Quality mounting structures are engineered to withstand wind speeds well above typical regional norms; coastal and cyclone-prone areas should specifically confirm the mounting structure's rated wind-load tolerance with the installer.

Hail Impact

Most certified panels are tested to withstand moderate hail impact as part of standard international certification — severe hailstorms can still cause damage, which is where panel insurance (where available) becomes relevant.

Monsoon & Waterproofing

Panels themselves are weatherproof by design, but poor-quality roof penetration during mounting is the more common source of monsoon leaks — proper installation with appropriate sealing prevents this.

Should You Insure Your System?

Some insurers offer specific solar asset insurance covering fire, theft, and weather damage — worth considering for larger systems or in regions with a history of severe storms, though it adds a small ongoing cost.

Standard net metering credits solar generation against usage at a single connection. Group or virtual net metering, where implemented by a state's regulations, allows a single solar installation's generation to be allocated across multiple electricity connections — such as several flats in one housing society, or a farmer's separate agricultural and household connections.

This matters most for apartment residents without individual roof access, letting the society install one shared system on the common terrace and credit the generation proportionally across participating flat owners' bills.

Availability and exact rules differ by state and DISCOM, and not every state has implemented this mechanism yet — check with your local electricity regulator or DISCOM before assuming it's available for your building.

PM-KUSUM (Pradhan Mantri Kisan Urja Suraksha evam Utthaan Mahabhiyan) supports farmers through three components: standalone solar irrigation pumps (Component B), solarising existing grid-connected agricultural pumps (Component C), and small decentralised solar power plants on farmers' land that can sell surplus power to DISCOMs (Component A).

For standalone solar pumps, farmers typically receive combined central and state subsidy support that can cover a substantial share of the cost, with the farmer contributing the balance — often partly through bank financing rather than entirely out of pocket. Land-owning farmers can also lease unused or marginal land for ground-mounted solar plants under Component A and earn a steady rental-style income.

Scheme timelines, subsidy percentages, and state-specific implementation details are revised periodically by the Ministry of New and Renewable Energy — farmers should check current guidelines on the official MNRE or their state nodal agency's portal before applying, since eligibility and windows can change.