Global solar capacity has more than doubled since 2020, with efficiency gains and storage integration setting the stage for even faster growth.
Image Credit: PreechaB/Shutterstock.com
Researchers have spotlighted solar photovoltaic (PV) as a key driver in the global shift toward cleaner energy due to falling costs, ongoing technological innovation, and scalable deployment.
Background
Solar PV has seen extraordinary growth in recent years, reshaping energy markets worldwide. According to the authors, global installed solar capacity doubled between 2020 and 2025, reaching over 1.5 terawatts (TW) by 2024. Several factors fueled this expansion, most notably a 30–40% drop in the Levelized Cost of Electricity (LCOE). This decline is largely attributed to economies of scale, improved technologies, and increased manufacturing capacity.
These cost reductions have made solar the most affordable new electricity source in many regions, spurring widespread investment and deployment. At the same time, PV technologies have rapidly advanced, particularly in developing high-efficiency crystalline silicon and tandem solar cells. These innovations push efficiencies beyond 27% today, with projections reaching approximately 34% by 2030. Higher efficiency is especially important in space-constrained settings, enabling greater energy output without increasing land use.
The Current Study
The authors employed a mixed-methods approach to assess the state of solar in 2025, combining quantitative data analysis with a qualitative policy review. Data sources include leading organizations such as the International Renewable Energy Agency (IRENA), BloombergNEF (BNEF), Lazard, and the U.S. National Renewable Energy Laboratory (NREL).
Key metrics analyzed include LCOE, installed capacity, energy storage costs, solar penetration rates, and grid curtailment. The research team gathered data through manual collection and web scraping, focusing on long-term datasets from 2010 to 2025. All costs were adjusted to 2025 US dollars to ensure consistency over time.
The team used Python tools like Pandas, Matplotlib, and Seaborn to visualize trends and regional differences. On the policy side, the study reviewed legislative frameworks at both national and regional levels. Major initiatives evaluated include the U.S. Inflation Reduction Act, the European Union’s REPowerEU strategy, and India’s Production Linked Incentive (PLI) schemes. The authors assessed these policies based on their financial incentives, permitting processes, and manufacturing support to understand how governance influences solar adoption.
The study integrates technical data and policy analysis to provide a well-rounded view of the forces shaping solar energy’s growth.
Results and Discussion
The findings point to sustained momentum in the solar sector, with global capacity surpassing 1.5 TW in 2024—more than double what it was in 2020. The primary catalyst continues to be cost. Utility-scale solar has become increasingly cost-competitive, often outpricing fossil fuel alternatives. The study emphasizes the sharp decline in LCOE and projects that, by 2030, module efficiencies could reach 34%, unlocking more energy generation per unit of land—particularly valuable in urban or land-limited regions.
Technology is playing a major role in this evolution. The emergence of tandem solar cells exceeding 27% efficiency at pilot scale is one example, with further improvements on the horizon as R&D accelerates.
Energy storage is another game-changer. The authors highlight that pairing solar with storage—especially lithium-ion batteries—has become standard practice worldwide. These hybrid systems extend solar's usefulness beyond daylight hours, reduce curtailment, and provide critical grid services. In the US, the share of new solar projects incorporating storage jumped from 15% in 2020 to over 60% in 2024.
Longer-duration storage technologies, such as flow batteries, solid-state systems, and thermal storage, are also being tested and deployed. These solutions are key to improving reliability, reducing overall system costs, and enabling grids to handle higher levels of solar penetration with greater flexibility.
Conclusion
The study concludes that solar PV has become an essential pillar in the push for a sustainable, low-carbon energy system. Rapid technological progress, declining costs, supportive policies, and the rise of integrated storage are all contributing to its accelerating adoption.
Continued investment, global collaboration, and creative policy design will be critical to unlocking solar’s full potential. Together, these efforts form the backbone of a cleaner, more secure, and more equitable energy future.
Journal Reference
Ehsan R., S. Ravi P. Silva. (2025). Solar Energy in 2025: Global Deployment, Cost Trends, and the Role of Energy Storage in Enabling a Resilient Smart Energy Infrastructure. Authorea. DOI: 10.22541/au.175647950.09188768/v1, https://www.authorea.com/users/960972/articles/1329770-solar-energy-in-2025-global-deployment-cost-trends-and-the-role-of-energy-storage-in-enabling-a-resilient-smart-energy-infrastructure