Methodology
How we calculate every tracker, which data we use, and what our numbers do and don’t cover.
Clean generation (CEA) × CEA grid emission factor for the same year = CO2 avoided.
On this page:
- Principles
- Carbon avoided by renewables
- The cost of waiting
- Power mix
- Renewable capacity
- Rooftop solar
- EV adoption
Principles
- Every figure cites its source, the period it covers, and the version of the dataset we used.
- We use official Indian government data first: the Central Electricity Authority (CEA), the Ministry of New and Renewable Energy (MNRE) and the Vahan vehicle registration system. Where those don’t cover a question, we use peer-reviewed research or established research groups.
- We say what a number covers and what it leaves out.
- We never publish our own forecasts. Future scenarios come only from published pathways.
- When data is revised, we update the tracker and note the change.
Carbon avoided by renewables
What it measures. How much carbon dioxide India’s renewable electricity kept out of the air in a financial year, compared with making the same electricity from the grid’s average mix.
Formula. CO2 avoided = renewable generation × grid emission factor.
- Renewable generation is grid-connected generation from solar, wind, small hydro, biomass and bagasse, and large hydro, from CEA generation reports, in billion units (BU). We show large hydro separately so readers can see the total with or without it.
- Grid emission factor is the all-India weighted average emission rate in tonnes of CO2 per megawatt-hour, from the CEA CO2 Baseline Database for the Indian Power Sector, for the same financial year. We use the latest version of the database and name it on the tracker.
One BU is one billion kilowatt-hours, or one million megawatt-hours. So BU × tCO2 per MWh gives the result directly in million tonnes (Mt) of CO2.
What we use today. The factor comes from version 22.0 of the database (August 2026): the weighted average grid emission rate that includes renewables and grid-connected captive plants, adjusted for cross-border power transfers. For FY2025-26 it is 0.675 tCO2 per MWh. Our headline figure includes large hydro; the year-by-year chart can be read either way, and our method explainer gives both totals. Generation for FY2019-20 to FY2021-22 large hydro comes from the CEA General Review; everything else comes from the CEA’s March renewable generation reports for each year. The CEA started counting captive plants in the factor from FY2022-23, so earlier years are not perfectly comparable with later ones.
Why the factor matters. The CEA publishes more than one emission rate. An average across all generation gives a lower, more conservative result than a rate based on fossil plants only. We name the exact rate and database version on the tracker, so anyone can check the figure.
What it doesn’t cover.
- It does not model which specific power plants ran less because renewables ran more.
- It counts only CO2 at the power plant, not emissions from manufacturing panels, turbines or batteries, and not other pollutants.
- Generation that isn’t reported to the CEA, such as some behind-the-meter rooftop solar, may not be fully captured.
The cost of waiting
The cost-of-waiting chart compares two paths for power-sector emissions: one at the current pace of change, and one with a faster shift. Both paths come from a single published source: an international agency such as the International Energy Agency (IEA), an IPCC pathway, a peer-reviewed study, or an official government target. We name the source and its assumptions under the chart. We do not create our own projections.
Today the chart uses the IEA’s World Energy Outlook 2024, Annex A, Table A.30: CO2 from India’s electricity and heat sector. The current pace is the IEA’s Stated Policies Scenario. The faster shift is its Announced Pledges Scenario, in which national targets, including India’s net zero by 2070, are met in full and on time. The IEA publishes values for 2023, 2030, 2035 and 2050 only, so we mark those years as points and join them with straight lines; we do not fill in the years between. The IEA counts emissions differently from the CEA, so these figures don’t compare directly with our carbon-avoided tracker. The IEA licenses this table under CC BY-NC-SA 4.0.
Power mix
The power-mix grid on the home page shows each source’s share of India’s utility electricity generation in a financial year, from the CEA’s renewable generation report (Table 6 for fossil, nuclear and large hydro; Table 1 for renewables by source). Fossil combines coal, lignite, diesel and gas. Hydro combines large and small hydro. Bio combines biomass, bagasse and what the CEA lists as waste-to-energy. Imports from Bhutan and captive plants that don’t supply the grid are left out. Shares are rounded to one decimal place, so they can add to 99.9 or 100.1.
Renewable capacity
Installed capacity from the Ministry of New and Renewable Energy’s (MNRE) monthly physical progress table: solar (ground-mounted, rooftop, hybrid and off-grid), wind, small hydro, bio-power, and large hydro as reported by the CEA, including pumped storage. It measures capacity built, not electricity generated: a gigawatt of solar produces far fewer units in a year than a gigawatt of coal. India’s 2030 goal is worded as 500 GW of non-fossil capacity, which also counts nuclear, so we compare it with the MNRE’s total non-fossil figure.
Rooftop solar
Households benefiting from rooftop systems commissioned under PM Surya Ghar: Muft Bijli Yojana, from the scheme’s national portal, which updates daily. The portal also reports systems installed, a smaller number, because one system can serve more than one household; we use households because the scheme’s goal is worded in households. Rooftop solar installed outside the scheme, including on commercial, industrial and government buildings, is not counted here. The renewable capacity tracker includes all grid-connected rooftop solar.
EV adoption
The share of new vehicle registrations that are battery-electric, from the Vahan public dashboard of the Ministry of Road Transport and Highways, covering all 36 states and union territories. We count the fuel types ELECTRIC(BOV) and PURE EV. Strong hybrids and plug-in hybrids are excluded. E-rickshaws count as three-wheelers, following Vahan’s own vehicle groups. Monthly counts are revised as late registrations arrive, and monthly shares swing with festive-season buying and new model launches, so we also show the month-by-month trend.