It took nearly seven decades - from the invention of the silicon solar cell in 1954 to 2022 - for the world to install its first terawatt (TW) of solar photovoltaic capacity. The second terawatt took less than three years. And in March 2026, just two years later, the world crossed the 3 TW mark.
Yet perhaps the most consequential development is not the speed of this growth, but where it is happening. After decades of being driven by wealthy nations and government subsidies, the solar PV boom is now shifting decisively toward developing countries - and analysts say this is only the beginning.
From 3 TW to 9 TW: An Unprecedented Acceleration
BloombergNEF (BNEF) predicts that the cumulative solar installations across the globe will cross the 9 TW mark in 2036. This means that the world needs to build at least one terawatt of solar energy every year in the coming ten years, which would be unimaginable a few years ago.
The first terawatt of installation was done in rich countries with government subsidies for renewable energy. After that, China took the baton and installed huge solar capacity and exported cheap solar panels to the developing countries, making the total capacity reach 2 TW by 2024 and 3 TW by 2026.
However, China's rapid installations have started putting pressure on its own infrastructure with transmission lines and storage facilities hurrying to catch up, thus resulting in the increase in curtailment of solar electricity in peak hours. In its recent 5-Year Plan, the Chinese government proclaimed initiatives to boost the renewable energy usage by more than 50%.
Developing Countries Take the Baton
With China's growth moderating, the next phase of the solar revolution belongs to the developing world. Most developing countries are starting with very low solar penetration in their grids and will not hit the limits that China and other early adopters are now facing. BNEF projects that by 2036, more than a quarter of all solar deployed globally will be in developing countries, while the share of wealthy nations will fall to about 20 percent. By that date, analysts project that poor countries will have installed more solar power than rich countries, excluding China.
The shift is already evident. The number of countries with at least 1 GW of installed solar capacity has grown from 42 in 2020 to 74 last year. Pakistan, Nigeria, the Philippines, Cuba, and Lebanon have seen extraordinary growth in rooftop solar installations in recent years.
Pakistan offers perhaps the most dramatic example. The country imported 17 GW of solar panels in 2024 alone - twice the volume of the previous year. Cumulative solar panel imports surged from under 1 GW in 2018 to more than 51 GW by early 2026. By some estimates, 20 percent of all electricity in Pakistan will come from solar by the end of this year. As a result, the country's fossil-fuel imports fell 40 percent between 2022 and 2024, shielding its economy from the volatility of Middle East energy disruptions.
Africa is experiencing a quiet but powerful solar revolution of its own. Between June 2023 and June 2025, sub-Saharan Africa's solar panel imports from China nearly tripled outside South Africa, rising from 3,734 MW to 11,248 MW. Twenty countries set individual import records, and 25 imported at least 100 MW each, up from 15 a year earlier. According to the Africa Solar Industry Association, the continent's actual installed capacity could be as high as 63.9 GW - far more than official project databases have captured.
Nigeria has emerged as one of the fastest-growing solar markets in sub-Saharan Africa. BloombergNEF reports that clean energy investment across 16 sub-Saharan African markets reached a record $13.5 billion in 2025, with small-scale solar investment more than doubling year-on-year to $8.5 billion. The report found that economic considerations, rather than climate ambition or government policy, are increasingly the primary drivers of the region's clean energy transition.
India, meanwhile, is poised to surpass the United States as the world's second-largest solar market in 2026, adding just over 50 GW of capacity this year. The country added 50 GW of solar capacity in just 14 months, pushing its total installed capacity beyond 150 GW.
Why Now? The Economics of Solar Have Changed
The reason behind this change is well known: economics. Prices of solar modules from China plunged from around $0.40 per watt in 2019 to about $0.07–$0.09 per watt by 2024–25. During the past decade, the prices of solar PV panels, batteries, and inverters fell by about 90 percent in China.
In the majority of African countries, solar energy has a competitor of diesel generators in the face of cheap power from the grid. In some areas, the time to recover investments drops to only 1–2 years, which results in the emergence of a market based not on subsidies but on commercial interest. Currently, around 85 percent of new capacities of installed solar energy in Africa come from the commercial and industrial sector where companies need fast and reliable power supply.
Challenges Ahead
Transitioning is not a simple task. Numerous developing nations suffer from the absence of a grid that can accommodate solar energy. In rural areas, grids were established for transmission of electricity only in one direction. These grids cannot deal well with decentralized generation of solar energy. Without the use of batteries to store the excess energy generated during the day and use it in the night, the solar energy boom will not last long.
Also, there no longer exists a possibility of getting solar energy modules cheaply. Authorities in China have restricted the establishment of new plants and have cut the volume of production. The polysilicon prices increased by 48% in September 2025; Wood Mackenzie estimates that they will continue to rise in the near future.
A New Era for Global Energy
Despite these challenges, the direction is clear. Solar power is no longer a luxury of the rich world. It is becoming the most economical and reliable source of electricity for hundreds of millions of people across the Global South.
"Take a train anywhere, say in the UK, and you're likely to spot solar panels," said Lara Hayim, head of solar research at BloombergNEF. Soon, the same will be true from Lagos to Lahore, from Islamabad to Jakarta.
The 3 TW milestone, remarkable as it is, will soon seem insignificant. The solar revolution's next chapter is being written not in the boardrooms of Europe or the policy halls of Washington - but on the rooftops of homes and businesses across the developing world.
