Renewable Energy
Energy sources that replenish naturally — solar, wind, hydro, geothermal, biomass — and produce far fewer emissions than fossil fuels.
Renewable energy refers to energy sources that are naturally replenished on human timescales: sunlight, wind, flowing water, geothermal heat, and biomass. Unlike fossil fuels, these sources don't deplete with use and produce dramatically lower emissions of greenhouse gases and air pollutants.
As of 2025, renewables — primarily wind and solar — are the cheapest source of new electricity in most of the world, having dropped roughly 80-90% in cost over the previous decade. Combined with battery storage, they can supply a large fraction of grid demand.
Major adoption is happening unevenly: countries like Norway, Iceland, and parts of the EU run high renewable shares; others (China, India) are scaling rapidly while still adding significant fossil capacity.