Since 2000 solar power has grown faster than any other source of electricity. What was once costly and limited to special applications is now widely deployable: modern photovoltaic modules are straightforward to install and operate and deliver very low-cost electricity across many regions.
Rapid capacity growth
Global solar capacity has climbed rapidly over the past decade:
– 2015: ~228 GW (about 1% of global electricity)
– 2020: ~759 GW (roughly 3% of demand)
– 2025: ~2,919 GW (around 10% of global energy, slightly above nuclear at 9%)
If current trends continue, global capacity could approach 9,000 GW by 2030, enough to meet more than 20% of worldwide demand.
China leading deployment and manufacturing
China is the clear leader. In 2025 it added roughly 315 GW, bringing total national capacity to about 1,300 GW. The country manufactures more than 80% of the world’s solar panels. Solar now supplies roughly 11% of China’s electricity, and coal’s share of the power mix has fallen from about 70% a decade ago to roughly 56%, driven largely by the rapid roll-out of renewables.
Europe’s accelerating build-out
The European Union has about 406 GW of solar capacity, meeting roughly 13% of its electricity needs. Coal’s share in the EU has fallen from around 25% in 2015 to about 9% today. Several countries already get over one-fifth of their electricity from solar—Greece, Cyprus, Spain and Hungary. Germany is the largest European market with roughly 119 GW installed, followed by Spain at about 56 GW.
United States and other growing markets
The United States ranks third globally with about 267 GW of solar, supplying roughly 8% of U.S. electricity (up from around 1% in 2015). Over the same period U.S. coal generation fell from about 34% to 17%. India (about 136 GW) and Japan (about 103 GW) each draw a meaningful share of power from solar (India ~8%, Japan ~11%). Brazil produces roughly 10% of its electricity from solar; together with hydro, wind and biomass, about 88% of Brazil’s power comes from renewables. Pakistan and South Africa have also seen rapid increases in solar’s share over the past decade.
Falling costs and abundant resource
Sunlight hitting Earth in an hour contains more energy than humanity uses in a year. With well under 1% of global land covered in panels, solar could meet global energy demand. Advances in module efficiency and mass production have driven dramatic price declines—roughly a 90% fall over recent years. In very sunny locations large utility-scale plants can produce electricity for near 0.01 euro (1 US cent) per kWh; in Germany utility-scale solar costs are around 4–5 euro cents per kWh. Rooftop systems frequently beat retail electricity prices by a wide margin, and adding battery storage typically raises costs by about 2–3 cents per kWh.
By comparison, the Fraunhofer Institute estimates current generation costs approximately as follows: nuclear 14–49 euro cents/kWh, coal 15–29 cents/kWh, and natural gas 15–33 cents/kWh.
System impacts and consumer benefits
New capacity additions in 2024 totaled about 632 GW worldwide: roughly 72% was solar, 18% wind, 4% gas, 3% coal, 2% hydro and 1% nuclear. Low-cost solar is reshaping transport and heating. Electric vehicles charged from rooftop PV can be substantially cheaper to run—savings versus diesel or gasoline in Germany can exceed 80% in some cases. Heat pumps are generally cheaper to operate than oil or gas systems; across the EU households typically save more than 30% on heating bills, with larger savings when electricity is supplied by on-site solar.
Outlook and remaining challenges
Past projections have routinely underestimated solar’s growth. For example, the IEA in 2020 forecast about 120 GW of new solar in 2024; the actual installations were roughly 597 GW that year. Many analysts now expect solar to become the dominant power source globally. One modelling study suggests a cost-effective future mix could include roughly 76% of energy from solar and about 20% from wind, with the remainder supplied by hydro, biomass and geothermal.
Key challenges remain: upgrading and expanding transmission and distribution networks; massively increasing storage capacity for nightly and seasonal balancing; integrating distributed storage including vehicle batteries; and improving digital controls to better match demand with variable supply (for example, smart EV charging that follows abundant solar generation). Addressing these issues will determine how quickly and smoothly solar moves from a leading growth technology to the backbone of many national power systems.
This article was originally published in German.