Solar Unit Price in India (2026): Per kWh Cost, Grid Tariffs & Savings

#Understanding Solar Unit Price: The True Economics of Rooftop Power in India

When Indian homeowners and commercial business operators evaluate rooftop solar systems, discussions inevitably revolve around capital expenditure: the price of solar panels, inverters, and mounting structures. However, savvy investors and electrical engineers measure energy investments through a far more insightful financial metric: the solar unit price.

In electrical engineering terms, a "unit" represents one kilowatt-hour (1 kWh) of electrical energy—the fundamental billing metric displayed on your monthly DISCOM electricity bill. Across Indian states, retail utility electricity tariffs range from ₹6.50 to ₹11.50 per unit for residential consumers, and escalate up to ₹14.00 per unit for commercial and industrial connections.

What if you could generate your own clean, reliable electricity on your roof at a fixed cost of under ₹2.00 per unit for the next 25 years?

Authored by Er. Dhramveer Joshi, Senior Solar Design Engineer holding an M.Tech in Electrical Power Systems, this authoritative analysis deconstructs the economics of solar unit price in India in 2026. We break down the Levelised Cost of Electricity (LCOE), DISCOM net-metering settlement tariffs, state-specific Generation-Based Incentives (GBI), and the exact generation benchmarks of 1 kW to 10 kW rooftop plants under the PM Surya Ghar scheme.

#Grid Electricity Unit Tariff vs. Solar Unit Price (LCOE)

To understand why rooftop solar is delivering 25% to 32% annual financial returns, compare what you currently pay your utility company against the lifetime cost of producing your own solar power.

What is the Levelised Cost of Electricity (LCOE)?

The Levelised Cost of Electricity measures the total net cost to build, finance, operate, and maintain a power generation asset divided by the total electricity (in kWh units) it will produce over its operational lifetime (25 years):

$$\text{LCOE (Solar Unit Price)} = \frac{\text{Net Turnkey Capex} + \text{Lifetime Maintenance (O\&M)}}{\text{Total Lifetime Generation (Units)}}$$

Here is a realistic financial calculation for a standard 3 kW residential rooftop solar plant in India under 2026 subsidy norms:

┌─────────────────────────────────────────────────────────────┐ │ 3 kW SOLAR UNIT PRICE (LCOE) CALCULATION │ ├─────────────────────────────────────────────────────────────┤ │ Gross Turnkey Plant Cost (3 kW Tier-1 DCR): ₹1,95,000 │ │ Less: PM Surya Ghar Central Subsidy Grant: -₹78,000 │ │ ─────────────────────────────────────────────────────────── │ │ Net Consumer Capital Outlay: ₹1,17,000 │ │ Add: 25-Year Inverter Replacement / O&M: ₹42,000 │ │ ─────────────────────────────────────────────────────────── │ │ Total 25-Year Lifetime Expenditure: ₹1,59,000 │ │ │ │ Total Units Generated over 25 Years: 1,08,500 kWh │ │ (Factoring 0.5% annual module degradation) │ ├─────────────────────────────────────────────────────────────┤ │ EFFECTIVE SOLAR UNIT PRICE OVER 25 YEARS: ₹1.46 / UNIT │ └─────────────────────────────────────────────────────────────┘

Even if you install a non-subsidised commercial system or include higher conservative maintenance costs, the solar unit price rarely exceeds ₹2.10 to ₹2.40 per unit. Compared to utility grid tariffs that rise every single year due to coal fuel surcharges and transmission infrastructure expansion, your rooftop solar plant freezes your cost of power at under ₹2.00 for a quarter of a century!

#State-Wise Grid Unit Tariff vs. Solar Unit Generation Economics

Electricity tariffs in India vary substantially by state, consumer category, and consumption slab. The table below illustrates the stark comparison between DISCOM residential grid tariffs and self-generated solar unit prices across leading Indian solar states:

Key Takeaway: In high-tariff states like Maharashtra, Delhi NCR, and Karnataka, every single solar unit generated saves between ₹6.00 and ₹10.00. This is why residential rooftop systems achieve full capital payback in just 2.4 to 3.1 years.

#Solar Unit Generation Matrix: How Many Units Will Your Roof Produce?

A frequent query among consumers is: "How many solar units can my roof generate every day and every month?"

In solar electrical engineering, generation is governed by the regional solar insolation index (measured in $kWh/m^2/day$), orientation tilt angle, inverter conversion efficiency, and temperature coefficient. On average across India, each 1 kWp of Tier-1 solar panels generates 4.0 to 4.5 units per day.

The matrix below provides engineering generation projections for standard rooftop plant sizes:

┌───────────────┬─────────────────┬──────────────────┬───────────────────┐ │ Plant Size │ Daily Units │ Monthly Units │ Annual Generation │ ├───────────────┼─────────────────┼──────────────────┼───────────────────┤ │ 1 kW Plant │ 4 – 4.5 Units │ 120 – 135 Units │ 1,450 – 1,600 kWh │ │ 2 kW Plant │ 8 – 9.0 Units │ 240 – 270 Units │ 2,900 – 3,250 kWh │ │ 3 kW Plant │ 12 – 13.5 Units │ 360 – 410 Units │ 4,350 – 4,900 kWh │ │ 4 kW Plant │ 16 – 18.0 Units │ 480 – 540 Units │ 5,800 – 6,500 kWh │ │ 5 kW Plant │ 20 – 22.5 Units │ 600 – 680 Units │ 7,250 – 8,100 kWh │ │ 8 kW Plant │ 32 – 36.0 Units │ 960 – 1,080 Units│ 11,600 – 13,000kWh│ │ 10 kW Plant │ 40 – 45.0 Units │ 1,200 – 1,350 U │ 14,500 – 16,200kWh│ └───────────────┴─────────────────┴──────────────────┴───────────────────┘

The PM Surya Ghar 300 Free Units Rule

The Central Government designed the PM Surya Ghar Muft Bijli Yojana around the objective of delivering 300 units of free power to every household. As demonstrated in the table above:

• A 2 kW system produces 240 to 270 units per month, covering roughly 80% to 90% of a 300-unit household consumption.
• A 3 kW system produces 360 to 410 units per month, comfortably providing 100% of the 300 free units target with buffer generation for hot summer months when air conditioning usage surges.

#Net-Metering vs. Gross-Metering: How Exported Solar Units Are Valued

When your solar plant generates more electricity during sunny afternoons than your home consumes, the excess solar units are automatically exported to the grid through a bi-directional net meter. How your DISCOM values these exported units directly impacts your financial yield:

1. 1:1 Energy Banking (Net Metering)

Under standard residential net-metering regulations across most Indian states, 1 solar unit exported equals 1 grid unit imported.

• If your home consumes 500 units in a month and your solar plant exports 400 units, your DISCOM bills you only for the net difference: 100 units.
• In this arrangement, your exported solar unit is effectively valued at the full retail tariff (₹7.50 to ₹9.00/unit), maximising consumer economic value.

2. Surplus Unit Banking Settlement (Feed-in Tariff / APPC)

If your system generates more units than you consume over the course of the financial year, the remaining unadjusted credit balance is paid out by the DISCOM at the Average Power Purchase Cost (APPC) or a benchmark feed-in rate:

• In Haryana (DHBVN/UHBVN), banked solar units are settled at approximately ₹2.60 per unit.
• In Maharashtra (MSEDCL), surplus units are settled at the approved APPC rate (~₹2.85 per unit).
• In Uttar Pradesh, unadjusted energy is compensated at the nodal buyback rate (~₹2.70 per unit).

Engineering Recommendation: Because retail utility tariffs (₹8/unit) are much higher than surplus buyback rates (₹2.70/unit), you should always size your solar plant to offset your actual annual kilowatt-hour demand rather than sizing for massive surplus export.

#The Delhi Solar Policy Bonus: Getting ₹3.00 Extra per Solar Unit (GBI)

A prime example of state-level solar unit incentivisation is the Delhi Solar Policy (2024–2027), enacted by the Government of NCT of Delhi.

Under this pioneering policy, residential rooftop owners in Delhi receive a Generation-Based Incentive (GBI):

• ₹3.00 per unit generated for residential rooftop systems up to 3 kW capacity.
• ₹2.00 per unit generated for residential systems between 3 kW and 10 kW.
• Paid monthly directly into the homeowner's bank account for five consecutive years!

The Compounding Benefit for a Delhi Homeowner:

1. Utility Bill Savings: 1 unit generated offsets ₹7.50 to ₹8.00 in grid electricity charges.
2. Direct GBI Cash Transfer: 1 unit generated earns ₹3.00 in direct government cash payouts.
3. Total Economic Value: ₹10.50 to ₹11.00 per solar unit!

For a 3 kW solar plant generating 4,200 units annually in Delhi, the GBI payout alone provides ₹12,600 in pure cash income each year, reducing the system payback time to an astonishing 2.1 years!

#4 Engineering Factors That Maximise Solar Unit Generation

To extract the lowest possible solar unit price over the life of your installation, ensure your contractor strictly adheres to these four technical standards:

1. True South Orientation & Optimal Tilt Angle:

In India, solar panels must face True South (azimuth angle 180°). The optimum tilt angle should match your city's latitude (e.g., 28° in Delhi/Gurugram, 19° in Mumbai, 13° in Bengaluru). A 10-degree deviation can degrade your annual solar unit yield by 4% to 7%.

1. N-Type TOPCon Cells with Low Temperature Coefficient:

Standard panels lose significant power when surface temperatures cross 45°C. Selecting modern N-Type TOPCon panels with a superior temperature coefficient of -0.30%/°C ensures higher generation during hot summer afternoons when air conditioners draw peak current.

1. Bi-Weekly Cleaning Protocol:

In dusty Indian urban corridors (the Indo-Gangetic plain), dust and particulate matter can reduce solar unit output by 1% to 2% per week. Implementing a simple bi-weekly morning hose rinse maintains peak generation without scratching the anti-reflective glass coating.

1. Independent Chemical Earthing (IS 3043):

Voltage fluctuations and lightning surges damage inverter sensitive semiconductor switches. Ensuring three independent chemical earth pits maintaining resistance strictly below 5 Ohms guarantees uninterrupted inverter uptime and uninterrupted unit generation.

#Conclusion: Lock In Your Solar Unit Price Today

With commercial and residential grid electricity tariffs scheduled to increase across DISCOMs to cover grid modernisations and fuel adjustments, continuing to purchase 100% of your power from the utility is an ever-increasing financial liability.

By installing a subsidised rooftop solar system under the PM Surya Ghar scheme, you immediately reduce your household or business solar unit price to under ₹1.60 per kilowatt-hour—locking in clean, abundant, inflation-free electricity for the next 25 years.

Calculate your exact monthly unit generation and PM Surya Ghar central subsidy today using our free PM Surya Ghar Sizing Calculator, or submit your installer proposal to our Quotation Scrutiny Portal to verify component quality and protect your 25-year return on investment!