Solar and home battery calculator

Estimate solar generation, household coverage, energy savings and simple payback, with an optional domestic battery scenario.

Last reviewed: 8 September 2026 · Methodology

Calculate

PV capacity (kWp)0 – 10,000Specific yield (kWh/kWp/year)1 – 3,000Household electricity (kWh/year)1 – 10,00,00,000Direct self-consumption (% of production)0 – 100Export price (per kWh)0 – 1,00,00,00,000Installation cost0 – 1,00,00,00,000Usable battery capacity before cycle losses (kWh)0 – 10,000Equivalent full cycles/year0 – 365Round-trip efficiency (%)1 – 100Additional battery cost0 – 1,00,00,00,000

Electricity price (INR/kWh)0 – 10,000

Country reference price selected.

₹8.00/kWh is an illustrative input, not an India-wide average or an official electricity tariff. Replace it with the applicable rate for your state, DISCOM, consumer category and consumption slab.

Last reviewed: 9 September 2026

Published prices and supplier examples

Each reference applies only to its stated period, area and customer profile. Fixed charges and partial bill components are shown for context; only comparable variable prices can be applied.

Tata Power-DDL · Delhi · 201–400 kWh/month
4.5 INR/kWh · Base schedule from 01 Oct 2021 · FY26 handbook
Domestic energy charge only, reproduced in the official FY26 customer handbook. This band applies within the household's monthly slab calculation, not to an appliance in isolation. Excludes fixed charges, PPAC/FPPAS, regulatory and pension surcharges, electricity tax and subsidies. The base schedule is published from 1 October 2021; verify current adjustments on your bill. This is not an all-India average or the full cost of a kWh.
Tata Power-DDL · Customer handbook FY26, pp. 9–10 · Last reviewed: 10 September 2026
Context only: this is not a complete variable price for estimating savings.
MSEDCL · Maharashtra · 101–300 kWh/month
10.8 INR/kWh · FY 2026–27 · from 01 Apr 2026
Domestic LT-I(B), sanctioned load below 20 kW, energy charge only. The applicable slab depends on the household's total monthly consumption. Wheeling of ₹1.60/kWh, fixed charges of ₹130/month (₹435 for three-phase), FAC, taxes and any subsidy are separate. This example is not a complete bill, supplier ranking or national average.
MSEDCL · Tariff order 25 March 2026, p. 95 · Last reviewed: 10 September 2026
Context only: this is not a complete variable price for estimating savings.

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Your estimate

Estimate — adjust the assumptions to your situation.

Annual saving₹19,600.00

Annual production7,000 kWh

Household demand covered with battery (%)74.44 %

Annual saving with battery₹26,800.00

Simple payback (years)0.41 years

Payback including battery (years)0.41 years

Battery-only payback (years)0.42 years

Battery energy delivered900 kWh

Exported energy3,550 kWh

Annual energy matching size (kWp)3.21 kWp

Illustrative variable rate per kWh. Replace with your bill; fixed charges are excluded.

Enter system size, annual yield per installed kWp, household consumption and a direct self-consumption share. Set your own installation costs, import price and export payment. These inputs describe a scenario; they are not a quotation or a site survey.

Formula

Annual generation = installed kWp × yield in kWh/kWp. Direct use is limited by household demand. Battery delivery is limited by surplus generation, capacity × cycles × round-trip efficiency, and remaining household demand. Savings value avoided imports and remaining exports.

Worked example

A 4 kWp array with an assumed yield of 1,000 kWh/kWp generates 4,000 kWh annually. At 40% direct self-consumption, 1,600 kWh supplies the home before adding a battery, provided demand is sufficient.

What the result means

Coverage is self-consumed energy divided by household consumption. Simple payback divides investment by annual savings. Battery payback uses only the extra savings attributable to storage, after the export income forgone.

Electricity price · India

Electricity duty, fuel or power purchase adjustments, fixed charges and subsidies depend on the applicable state and DISCOM rules. No national tax percentage or subsidy is assumed. Slab thresholds, sanctioned-load charges and time-of-day tariffs are not automatically modelled.

Assumptions and limits

Annual totals cannot model hourly matching, winter shortages, roof shading, degradation, financing or future tariffs. Battery capacity is treated as energy charged per cycle.

Questions answered

Does matching annual generation mean independence from the grid?

No. Production and demand still occur at different times.

Why is payback sometimes unavailable?

There is no finite simple payback when estimated annual savings are zero or negative.

Methodology · Report an error

Data sources

Last reviewed: 2026-09-08