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What is green energy?
Green energy is energy produced from natural, renewable sources — such as sunlight, wind, water, the Earth’s heat and organic matter — that release little or no greenhouse gases and cause minimal harm to the environment. All green energy is renewable, but not every renewable or clean source qualifies as green: what defines it is a very low environmental impact.
The three notions are often confused, yet they do not overlap exactly. Renewable energy is defined by its source: nature replenishes it faster than we consume it. Clean (or low-carbon) energy is defined by its emissions: it releases little or no CO2, whether it is renewable or not. Green energy sits at the intersection — it is both renewable and clean.
| Notion | Criterion | Examples |
|---|---|---|
| Green energy | Renewable AND clean (very low environmental impact) | Solar, wind, small hydro, biogas |
| Renewable energy | The source regenerates naturally and continuously | Solar, wind, hydro, biomass, geothermal |
| Clean / low-carbon energy | Emits little or no CO2, without necessarily being renewable | Nuclear, but also all renewables |
Advantages of green energy
The advantages of green energy go far beyond the climate. Here are the main benefits, backed by the latest figures:
- No direct greenhouse gas emissions: wind, solar and hydro generation releases no CO2, which makes green energy the main tool against global warming;
- Cleaner air and better health: unlike coal or oil, green sources emit none of the fine particles, sulphur and nitrogen oxides that pollute the air of large cities and damage public health;
- Rapidly falling costs: generating a solar kWh costs around 90% less than in 2010, and solar and onshore wind are now the cheapest sources of new electricity in most of the world, according to IRENA;
- Energy security and independence: the sun and the wind cannot be imported, embargoed or depleted, so producing green energy locally reduces exposure to fossil fuel price shocks;
- Millions of local jobs: renewables employed 16.6 million people worldwide in 2024 — including around one million in India — according to the IRENA and ILO annual review;
- An inexhaustible supply: green sources replenish themselves naturally, whereas proven oil and gas reserves would last only a few more decades at current consumption rates.
On top of these collective benefits, choosing green electricity or green gas at home can also help you make savings on your energy bills and shrink your carbon footprint.
Disadvantages of green energy
To be fair, green energy also has limits. None of them is a deal-breaker, but they explain why the transition takes time:
- Intermittency: solar panels only produce during the day and wind turbines only when the wind blows, so grids need storage (batteries, pumped hydro) and flexible back-up to keep supply steady;
- Land use and local impacts: large solar parks, wind farms and reservoirs occupy space and can affect landscapes and biodiversity, which must be managed case by case;
- High upfront investment: building a wind farm, a dam or a rooftop solar system requires significant capital, even if the fuel is then free for decades.
What are the types of green energy?
Green energy comes from five main natural sources: the sun, the wind, water, the Earth’s heat and biomass. Each family has its own technologies and uses:
| Green energy | Source | Technology | Use |
|---|---|---|---|
| Solar energy | Sun | Photovoltaic panels, solar thermal collectors | Electricity, heating, hot water |
| Wind power | Wind | Onshore and offshore wind turbines | Electricity |
| Hydropower | Water | Dams, run-of-river plants | Electricity, storage |
| Geothermal energy | The Earth’s heat | Geothermal plants, heat pumps | Electricity, heating and cooling |
| Bioenergy | Biomass | Combustion, biogas plants, biofuels | Electricity, heat, transport |
In short: solar energy converts sunlight into electricity or heat — see our guide to solar panels; wind energy captures the kinetic energy of the wind, onshore and offshore; hydropower turns the movement of water into electricity and remains the largest single renewable source; geothermal energy taps the Earth’s heat and, unlike solar and wind, is not intermittent; and biomass turns organic waste into heat, electricity or biogas through combustion or fermentation.
For a detailed look at each of the five families, their pros and cons and the world’s landmark projects, read our full guide to renewable energy.
Green energy around the world
2025 was a turning point. Renewables generated 33.8% of the world’s electricity and overtook coal (33.0%) for the first time in a century, according to the Global Electricity Review by Ember. The same year, the world installed a record 692 GW of new renewable capacity — solar alone accounting for roughly three quarters of the additions — according to IRENA. At COP28, nearly 200 countries pledged to triple global renewable capacity by 2030, a cornerstone of the energy transition.
India is one of the fastest-growing green energy markets in the world. In June 2025, the country reached 50% of its installed power capacity from non-fossil sources — five years ahead of the 2030 target set in its national climate commitments, according to the Ministry of New and Renewable Energy. Its total installed capacity passed the 500 GW mark in September 2025, and the country is now heading for 500 GW of non-fossil capacity by 2030, driven by giant solar parks such as Bhadla in Rajasthan and roughly 48 GW of renewable additions in 2025 alone.
How to choose green energy at home?
You do not need solar panels on your roof to use green energy. In most markets, households can subscribe to a green tariff: for every kWh you consume, your supplier guarantees that an equivalent kWh of renewable electricity is injected into the grid. This guarantee relies on tracking certificates:
- in Europe, suppliers back green tariffs with guarantees of origin (GOs), one certificate per MWh of renewable electricity;
- in India, renewable energy certificates (RECs) are traded on the power exchanges, and many distribution companies (DISCOMs) offer a green tariff that lets consumers buy electricity bundled with renewable attributes;
- internationally, companies and households can also buy voluntary I-RECs to match their consumption with renewable generation.
Contrary to a common belief, green tariffs are not necessarily more expensive than standard ones — the cost of generating solar and wind power has collapsed over the past decade. Compare the offers available in your market with our guide to green energy suppliers, then simply contact the supplier of your choice: switching usually takes a few weeks at most and requires only your address, a meter reading and your payment details.