Understand the roof, the land and the numbers before making a commitment.
Photovoltaic cells in panels produce DC electricity. An inverter turns it into the AC electricity your home uses. Solar supplies daytime demand first; the grid supplies any shortfall. An approved meter records imports and surplus exports.
A normal grid-connected system shuts down during a power cut to protect workers. Backup requires suitable equipment and usually a battery, which this estimate does not include.
kW describes rated system power. kWh, also called a unit, measures energy. A 2 kW system operating at full output for one hour produces 2 units.
The calculator starts with 5 equivalent full-sun hours × 80% performance: about 4 units per kW per day. A six-hour assumption gives 4.8 units after those losses—not six guaranteed units. Equivalent full-sun hours are not the number of daylight hours. Weather, heat, orientation and season change output.
Allow roughly 70–100 sq ft per kW; our planning rule uses 100. A 3 kW example therefore needs about 300 sq ft, including sensible access and spacing. Exclude tanks, shaded areas and obstructed walkways.
Have the installer assess structural loading, waterproofing, wind anchoring, earthing, lightning protection and safe maintenance access. Check ownership/RWA permissions, sanctioned electrical load and DISCOM requirements.
Running appliances during sunny hours can replace electricity bought at your retail tariff. Night-time demand still comes from the grid unless there is storage. Direct-use share is an estimate of how your daytime demand matches solar output.
Exported units follow your DISCOM’s net-metering or other settlement rules. They may offset later imports, earn a different rate, or have limits. We default export value to zero until you enter a confirmed rate. Fixed charges can remain even when unit purchases fall.
For a simple 1–5 kW home installation, the calculator uses an indicative ₹65,000/kW before subsidy: approximately ₹65,000 for 1 kW, ₹1.30 lakh for 2 kW, ₹1.95 lakh for 3 kW or ₹3.25 lakh for 5 kW.
These are planning estimates, not a national price list. Compare itemised quotes covering panels, inverter, mounting, wiring, protection, metering and approvals. Batteries, unusual roof work and connection upgrades can add cost.
Arrange safe cleaning based on local dust and inspect wiring, supports and inverter performance. Never walk on panels or work on live electrical equipment. Ask what cleaning and maintenance the vendor contract includes.
Eligible programme vendors provide five-year comprehensive maintenance; clarify exclusions. Our editable 1% annual allowance is a budgeting assumption. Simple payback ignores loan interest, degradation and future inverter replacement, so it is not a guaranteed return.
Planning reference: BSES rooftop guidance. Local tariffs and settlement rules must come from your DISCOM.
Choose a household example, then adjust it to your bill and usable roof. Every amount is an estimate.
Planning defaults: 100 sq ft/kW, 5 equivalent full-sun hours × 80% performance, 50% direct use, ₹65,000/kW installed and 1% annual maintenance allowance. The tariff and usage are examples, not your city’s tariff. No battery is included.
Two different decisions: produce electricity on land, or use solar to power irrigation. Their costs, approvals and support are not interchangeable.
Ground-mounted panels connect through inverters, transformers and an evacuation line to a permitted grid connection. You can develop a project and sell electricity under a power purchase agreement (PPA), or lease suitable land to a developer.
A land lease can provide rent without owning the plant, but check payment security, escalation, access rights, taxes, restoration and the lease term. Ownership brings construction, financing and operating risks.
A planning allowance is about 4–5 acres per MW; terrain and panel layout can change this. Confirm clear title or a long-term lease, permitted land use, drainage, flood risk, road access, cleaning water and security.
Ask the DISCOM about available substation capacity and connection distance before buying equipment. Transformer, line, right-of-way and grid-upgrade costs can make an otherwise suitable site uneconomic.
Use ₹3.5–4.5 crore per MW only as an early budget assumption, excluding land and major connection upgrades; obtain current EPC quotes. The ₹3.5 crore/MW scheme benchmark is not a guaranteed market price.
At an assumed 18% capacity factor, 1 MW generates about 15.77 lakh units/year (1,000 × 8,760 × 18%). At an illustrative ₹3/unit contracted tariff, gross revenue is about ₹47.30 lakh/year. The actual PPA tariff may be different.
Deduct maintenance, security, insurance, lease rent, cleaning, grid losses, curtailment, interest and taxes. Check payment delays, degradation, replacement reserves and contract obligations. Do not borrow on the basis of the gross-revenue example.
For electricity used on-site, savings depend on avoided tariffs and applicable open-access or network charges. Obtain a site-specific engineering and financial study before signing a PPA or finance agreement.
Size the pump for water demand, seasonal water level, total pumping head and pipe losses—not horsepower alone. Standalone solar pumps mainly operate in sunshine; water storage can help schedule irrigation. Grid-connected solarisation is a different design.
As a rough budgeting example, a 3–5 HP solar pumping installation may require several lakh rupees; use the state tender’s approved model and cost, not a generic per-kW home-rooftop quote. Check borewell condition, pump/controller compatibility, dry-run protection, warranty and local service.
Cheap pumping does not make groundwater unlimited: use irrigation scheduling and water-saving practices.
Sources: SECI land-planning guidance · MNRE PM-KUSUM overview. Farm costs, yield and tariff above are explicit planning assumptions.
Standard central assistance is ₹30,000/kW for the first 2 kW plus ₹18,000 for the next kW: maximum ₹78,000. Fractional capacity is prorated. Special-category central rates are ₹33,000 and ₹19,800, capped at ₹85,800; confirm whether your state/UT qualifies.
This is for eligible residential grid-connected systems, with compliant Indian-made cells and modules, a registered vendor, DISCOM approval and commissioning. Commercial rooftops and ground-mounted farm plants are not covered by this residential grant. Prior subsidised installations have specific expansion rules. Programme implementation runs to 31 March 2027.
Paying a vendor does not guarantee grant approval. Verify state top-ups separately.
Official application portal ↗The national scheme closed on 31 March 2026. The 28 September 2026 clarification allows qualifying previously sanctioned projects to finish by 31 March 2027. This is not a blanket reopening for new applications.
Component A historically covered 500 kW–2 MW decentralised plants selling under a DISCOM PPA. It did not give every landowner the pump subsidy. Landowners could develop a project or lease to a developer.
Components B and C supported standalone pumps and solarisation of existing pumps. Under qualifying sanctioned projects, the usual pattern was central 30% plus state 30% assistance, with different special-area provisions and state contributions. These percentages are not an offer of fresh support today.
New applicants should contact the state nodal agency/DISCOM for an active tender, allocation or successor programme. Existing applicants should verify their sanction, vendor, contribution and completion deadline. Pay only through officially specified channels.
Official PM-KUSUM information ↗Renew India provides independent education. It is not a government application portal, installer or guarantee of financial returns.