Sunlight: Abundance
Thousands of times our needs, and how little we catch
What this tab covers How much of this energy there is: the natural flow or stock, the share that could be harnessed, and how much is used today, compared with world primary energy use (592 EJ in 2024).Sunlight is by far the largest energy flow reaching the Earth: thousands of times world energy use. In 2024 solar power supplied 2,131 TWh of electricity, about 1.3% of world primary energy.
A flow: renewed continuouslyHow much there is
| Measure | Value | Compared with world energy use | Note |
|---|---|---|---|
| Sunlight intercepted by the Earth | about 173,000 TW1 | about 9,200 times world primary energy use | Calculated as 1,361 W/m2 times the Earth's cross-section (radius 6,371 km). About 5.5 million EJ a year. |
| Sunlight absorbed at the surface | about 82,000 TW2 | about 4,400 times world primary energy use | Calculated as 161 W/m2 times the Earth's surface area (510 million km2). About 2.6 million EJ a year. |
| Technical potential of utility-scale PV, CSP, onshore and offshore wind combined | more than 100 PWh of electricity per year7 | more than 0.6 times world primary energy use (over 360 EJ of electricity) | A review of potential studies; the source groups solar and wind together. Electricity is worth more than primary energy, so the comparison understates it. |
| Solar electricity generated in 2024 | 2,131 TWh6 | about 1.3% of world primary energy use (7.7 EJ) | Up 474 TWh (29%) on 2023; 6.9% of world electricity. |
| Installed PV capacity, end of 2024 (DC panel rating) | about 2,250 (2,246.5) GW11 | not applicable (capacity, not energy) | IEA PVPS converts all national data to DC panel ratings, including China's utility-scale data, which are officially reported in AC. The Energy Institute reports 1,865 GW. |
| World primary energy use (baseline) | 592 EJ in 20245 | 1 | Total energy supply, Energy Institute (physical energy content method). Installed solar capacity at end-2024: 1,865 GW. |
The flow is not the constraint. Even the sunlight absorbed at the ground is several thousand times what humanity uses, and the technical potential of solar and wind electricity together exceeds 100 PWh a year. The limits are land, cost, storage and grids, not the resource.
Use is growing fast from a small base. Two capacity figures circulate for the end of 2024: the Energy Institute counts 1,865 GW, the IEA PVPS programme about 2,250 GW. The main reason is counting convention: PVPS uses the DC rating of the panels, while some national statistics (China's utility-scale data, for example) count AC inverter capacity, which is usually lower. Likewise, PVPS says PV covered more than 10% of world electricity consumption, but that is a theoretical figure from year-end capacity and ideal conditions, which the report itself calls optimistic; Ember's measured output gives 6.9% of generation.
Sources
- Solar Irradiance: Science NASA Goddard Space Flight Center, 2024
- The global energy balance from a surface perspective (Wild et al., Climate Dynamics 40, 3107-3134) Springer / RERO DOC, 2013
- Energy Institute Statistical Review of World Energy 2025 (74th edition) Energy Institute (with KPMG and Kearney), 2025
- Global Electricity Review 2025: Global electricity source trends Ember, 2025
- The global technical, economic, and feasible potential of renewable electricity (Angliviel de La Beaumelle et al., Annual Review of Environment and Resources 48) Pacific Northwest National Laboratory, 2023
- Snapshot of Global PV Markets 2025 (capacity in DC; electricity share is a theoretical estimate) IEA Photovoltaic Power Systems Programme, 2025