Solar photovoltaic energy has become the cheapest source in the world and is growing at a rapid pace, displacing coal, gas, and nuclear energy.
- In 2015, 228 GW were installed (1% of global electricity).
- By 2020, it was 759 GW (3%).
- For 2025, 2919 GW (10%) are projected, surpassing nuclear energy for the first time.
- By 2030, 9000 GW could be reached, covering more than 20% of global demand.
Global Leadership
- China: 1300 GW installed in 2025, with 11% of its electricity coming from solar energy. It produces more than 80% of the world’s solar panels.
- European Union: 406 GW, with 13% of its solar electricity. Germany (119 GW) and Spain (56 GW) are regional leaders.
- United States: 267 GW, covering 8% of its electricity demand.
- India: 136 GW (8%).
- Japan: 103 GW (11%).
- Brazil: 65 GW (10%), with a renewable matrix reaching 88%.
- South Africa and Pakistan: rapid growth, reaching 10% and 20% respectively in 2025.
Costs and Competitiveness
The price drop has been decisive:
- Solar installation costs have dropped by 90% in recent years.
- Large solar parks produce electricity for 1 euro cent/kWh in sunny rural areas.
- In Germany, the cost is 4-5 cents/kWh.
- Domestic solar electricity costs less than half the usual grid price in Europe.
- According to Bloomberg NEF, costs will fall another 30% by 2035.
In comparison:
- Nuclear: between 14 and 49 cents/kWh.
- Coal: between 15 and 29 cents/kWh (84 cents if climate costs are included).
- Gas: between 15 and 33 cents/kWh (49 cents with climate costs).
The Sun irradiates more energy in one hour than humanity consumes in a year. With solar panels on less than 1% of the Earth’s surface, the entire world’s energy demand could be covered.
Innovation and Storage
One of the major challenges of solar energy is its intermittency: it only produces electricity when there is sunlight. However, advances in lithium batteries, thermal storage, and hybrid systems are allowing solar energy to become a reliable and continuous source. Storage adds between 2 and 3 cents per kWh but ensures stable supply even during nighttime or cloudy days.
Additionally, integration with smart grids and the development of bifacial panels (which capture energy on both sides) increase efficiency and reduce costs.
Solar energy is emerging as the main global energy source. Researchers from the Lappeenranta University of Technology estimate it could cover up to 76% of global electricity in the future. Its exponential growth, reduced costs, and ability to displace polluting sources make it the cornerstone of the energy transition towards a sustainable model.
