In the financial year that ended in March 2026 (FY2025-26), India’s renewables, including large hydro dams, kept about 320 million tonnes (Mt) of carbon dioxide (CO2) out of the air, by our estimate. That is the headline figure on our tracker. Without large hydro, solar, wind, small hydro and bio power account for about 207.6 Mt.
For scale, the Central Electricity Authority (CEA), which publishes India’s official power statistics, puts total CO2 from grid electricity that year at 1,189 Mt (Central Electricity Authority, CO2 Baseline Database version 22). Here is every step, so anyone can check it.
Step 1: add up the clean electricity
We start with grid-connected generation by source, in billion units (BU). One BU is a billion kilowatt-hours. For FY2025-26 (Central Electricity Authority, renewable generation report, March 2026):
- Solar: 174.76 BU
- Wind: 106.70 BU
- Small hydro, meaning plants up to 25 megawatts: 12.01 BU
- Bio power from biomass and bagasse, the fibre left after crushing sugarcane: 14.08 BU
- Large hydro: 167.20 BU
The first four add up to 307.55 BU, and 474.75 BU with large hydro. We show large hydro separately so readers can see the result either way. The CEA also lists 3.03 BU from other sources, which it describes as waste-to-energy. We leave these out for now.
Step 2: pick a grid emission factor
A grid emission factor says how much CO2 the grid releases for each unit of electricity. We use the CEA’s all-India weighted average emission rate from the CO2 Baseline Database for the Indian Power Sector, version 22, published in August 2026. For FY2025-26 it is 0.675 tonnes of CO2 per megawatt-hour (tCO2/MWh) (Central Electricity Authority, CO2 Baseline Database version 22).
This rate divides the CO2 from all grid-connected power stations by all the electricity they supplied, including renewables, power that factories with their own generators feed into the grid, and net imports. The database labels it “Weighted Average Grid Emission Rate (Incl. RES,Captive)”, where RES means renewable energy sources. We use the version adjusted for imports.
Step 3: multiply
One BU is one million megawatt-hours, so BU multiplied by tonnes per megawatt-hour gives million tonnes directly.
- Without large hydro: 307.55 BU × 0.675 = 207.6 Mt
- With large hydro: 474.75 BU × 0.675 = 320.5 Mt
The trend since 2019-20
We repeat the sum for each year, with that year’s generation and its factor from database version 22. Large hydro for FY2019-20 to FY2021-22 comes from the CEA’s annual statistics (Central Electricity Authority, General Review 2025).
| Financial year | Grid factor (tCO2/MWh) | Mt avoided, without large hydro | Mt avoided, with large hydro |
|---|---|---|---|
| 2019-20 | 0.709 | 97.8 | 208.3 |
| 2020-21 | 0.698 | 101.6 | 206.6 |
| 2021-22 | 0.711 | 119.9 | 227.7 |
| 2022-23 | 0.716 | 143.9 | 260.0 |
| 2023-24 | 0.727 | 162.2 | 259.6 |
| 2024-25 | 0.710 | 179.0 | 284.5 |
| 2025-26 | 0.675 | 207.6 | 320.5 |
Without large hydro, CO2 avoided more than doubled in six years. Solar did most of the work, rising from 50.13 BU in FY2019-20 (Central Electricity Authority, renewable generation report, March 2021) to 174.76 BU in FY2025-26, when it generated more electricity than large hydro (Central Electricity Authority, March 2026). With large hydro the line is bumpier, because hydro output swings: 162.10 BU in FY2022-23, then 134.05 BU in FY2023-24 (Central Electricity Authority, renewable generation report, March 2024).
The progress shows up across the grid. Total CO2 from grid electricity fell from 1,236 Mt in FY2024-25 to 1,189 Mt in FY2025-26, while net generation rose from 1,741 BU to 1,761 BU (Central Electricity Authority, CO2 Baseline Database version 22). The CEA puts the lower emission rate down mainly to non-fossil generation, which it says grew by about 16%.
The cost of waiting is just as plain. Fossil fuel plants still generated 71% of India’s electricity in FY2025-26 (Central Electricity Authority, March 2026), and each BU from that fleet releases close to 1 Mt of CO2, at the CEA’s operating margin of 0.963 tCO2/MWh.
Why the choice of factor matters
The CEA publishes more than one emission rate, and they give very different answers. For FY2025-26, from version 22 of the database:
- Weighted average including renewables, 0.675 tCO2/MWh: 207.6 Mt without large hydro, 320.5 Mt with it. This is the rate we use.
- Weighted average of conventional generation only, which leaves renewables out of the calculation, 0.818 tCO2/MWh: 251.6 Mt and 388.3 Mt.
- Simple operating margin, the average for fossil fuel plants only, 0.963 tCO2/MWh: 296.2 Mt and 457.2 Mt.
We use the first because it is the CEA’s headline figure, the database gives it for every year in our series, and it gives the lowest result. We would rather understate than overstate.
One side effect: because renewables sit inside this average, the factor falls as they grow, so each new unit of clean power is credited with a little less CO2.
What the number covers, and what it doesn’t
- It is an average-grid estimate. It does not model which coal or gas plants actually ran less.
- It counts only CO2 released at the power station, not emissions from making panels, turbines and batteries, from mining and moving fuel, or other pollutants.
- It covers generation reported to the CEA. In March 2026 the CEA had generation data for 116 gigawatts (GW) of the 150 GW of solar installed, so some rooftop systems may be missing (Central Electricity Authority, March 2026).
- The CEA revises its figures, and from FY2022-23 it began counting power that factories feed into the grid, so earlier years are not perfectly comparable with later ones.
The full series, with sources for every year, is in our carbon avoided tracker.