Over the last decade, solar power has transformed from a niche technology into a mainstream energy solution. At the heart of this revolution is a relentless pursuit of higher efficiency, which has made solar PV more powerful, more affordable, and more accessible than ever before. For a country like the UK, where space can be at a premium, getting more power from each square metre of panel is a game-changer.
Here we will explore the significant improvements in solar PV module efficiency over the past ten years, the technologies that have driven this progress, and what the future holds for this rapidly evolving field.
A Decade of Exponential Growth
A decade ago, a typical residential solar panel had an efficiency of around 15% to 17% and a power rating of 250W. Today, it is commonplace to see panels with efficiencies of over 22%, with some of the most advanced models reaching up to 24.8% (Clean Energy Reviews, 2025). This remarkable leap means that a standard panel now has a power output of over 450W, sometimes exceeding 600W for larger modules.
This progress has been driven by leading manufacturers, many of which are headquartered in China and are major players in the global market. Companies such as JinkoSolar, Trina Solar, and JA Solar, alongside South Korean giant Hanwha Q Cells, have consistently pushed the boundaries of what's possible. Trina Solar, for instance, has a history of setting multiple world records for efficiency (GI Energy). These innovations are not just theoretical; they are rapidly being integrated into commercial products, making high-efficiency solar available to everyone.
The Technology Behind the Gains
So, what's been happening behind the glass and silicon to make this possible? The key improvements have largely been in cell design, manufacturing processes, and materials science.
1. The Shift to Monocrystalline Panels and N-Type Technology
Ten years ago, a significant portion of the market was still using polycrystalline panels. These were cheaper to produce but had lower efficiency, peaking at around 18% (Clean Energy Reviews, 2025). The industry has now almost entirely shifted to monocrystalline panels, which are more efficient due to their uniform crystal structure.
More recently, a crucial development has been the widespread adoption of N-type silicon cells. Traditional cells are p-type, meaning they are doped with boron. N-type cells are doped with phosphorus and are more resistant to degradation, particularly from light-induced degradation (LID), which can cause efficiency to drop in the first year of operation. This stability results in a higher long-term energy yield.
2. Advanced Cell Architecture
To capture more light and reduce power loss, manufacturers have developed innovative cell architectures:
- Heterojunction (HJT) Cells: These cells combine two different types of silicon: an amorphous thin layer on top of a crystalline silicon base. This 'hybrid' approach reduces power loss at the cell's surface, leading to higher efficiency and better performance in high temperatures (Green Tech Hub, 2025).
- Tunnel Oxide Passivated Contact (TOPCon) Cells: TOPCon technology involves adding a very thin layer of silicon oxide to the cell's back surface. This layer acts as a 'passivation' layer, reducing electron recombination and allowing for greater energy output. Many manufacturers, including JinkoSolar and Trina, have embraced TOPCon technology in their latest product lines (Sunsave, 2025).
- Back-Contact (BC) Cells: Panels with back-contact cells, also known as Interdigitated Back Contact (IBC), move all the electrical contacts to the back of the cell. This eliminates the need for busbars—the metallic strips on the front of the panel that collect current—which can partially shade the cell. By removing this shading, more sunlight reaches the silicon, boosting efficiency. Brands like Maxeon (formerly SunPower) have long been pioneers of this technology (Clean Energy Reviews, 2025).
The Future is Now: Pushing the Boundaries
With standard silicon cells approaching their theoretical efficiency limit of around 29.4% (Department of Energy, 2025), the next frontier for solar technology is in innovative materials and multi-layered designs.
The Perovskite Promise
The most talked-about material in solar research today is perovskite. Perovskites are a class of crystalline compounds that are highly effective at absorbing sunlight and converting it into electricity. Their potential is immense for several reasons:
- High Efficiency: Perovskite solar cells have already reached efficiencies of over 26% in lab settings (Department of Energy, 2025).
- Cost-Effective Manufacturing: They can be made using low-temperature processes and even printed from a liquid ink, which could drastically reduce production costs.
- Flexibility and Versatility: Perovskites can be made into thin, lightweight, and flexible films, opening up new applications like solar-powered clothing, windows, and flexible rooftops (IDTechEx, 2025).
The Power of Tandem Cells
The real breakthrough comes from combining perovskite with traditional silicon. This is known as a tandem solar cell. A tandem cell uses a perovskite layer on top of a silicon cell. The perovskite layer is optimised to capture high-energy blue and violet light, which silicon doesn't absorb as well. The silicon layer then absorbs the lower-energy red and infrared light that passes through the perovskite.
This 'best of both worlds' approach allows the cell to capture a much broader spectrum of sunlight. This has led to groundbreaking efficiency records. In June 2025, a Chinese manufacturer announced a crystalline silicon-perovskite tandem solar cell with a certified conversion efficiency of a staggering 33% on a large area (LONGi, 2025). This is the first time a mass-producible solar cell has surpassed the 33% efficiency mark.
While still largely a lab-based technology, the rapid progress suggests that perovskite-silicon tandem cells could become commercially available within the next few years, potentially dominating the market by the end of the decade (IDTechEx, 2025).
A Brighter Future
The last ten years have shown us that the pace of solar innovation is accelerating. We have moved from average efficiencies of 15% to high-performance panels exceeding 24% through clever engineering and a shift to N-type technologies.
The next ten years promise to be even more exciting, with the commercialisation of perovskite and tandem cell technology pushing the boundaries of what we thought was possible. For the UK, these advancements mean smaller, more powerful solar arrays that generate more electricity, further accelerating our transition to a cleaner, more sustainable energy system.