The next steps for solar PV

IEC ETech

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Solar photovoltaic (PV) energy has already reached a point where it is economically competitive and globally scalable. What is its likely evolution in years to come? And what new standards are on the cards?

Solar PV accounts for almost 80% of the increase in the world’s renewable capacity and its low cost and broad social acceptance will contribute to a doubling of capacity over the next five years, according to the IEA. In 2025, new global solar installations reached 606 Gigawatt (GW)and solar alone accounted for more than twice 2020’s entire renewables installations.

Despite policy headwinds in the US where federal subsidies for renewables have been rolled back, the IEA predicts the global amount of installed renewable power will more than double to 4 600 GW by 2030 with solar PV accounting for the lion’s share.

For this reason, analysts at McKinsey judge solar PV “to be the success story of the energy transition”. They cite the continued decline in costs and relative easy installation of solar PV panels, which have spurred adoption of enterprise scale, commercial and residential use alike.

“Modules still account for roughly 30 to 40% of utility-scale system costs, so reducing their price has had a major impact,” says Dr Tony Sample, the Chair of IEC TC 82, the technical committee which produces standards for PV systems “Now we’re reaching a point where labour and financing costs are becoming the most important variables.”

Low module prices drive growth

The rapid scale-up of production in Southeast Asia has driven module prices down dramatically. China’s solar market alone grew by 30%, adding another 329 GW of capacity by the end of 2024, over half of new global capacity that year. “Solar PV is a unique technology,” says Sample. “It’s completely scalable. You can go from powering a digital watch, to off-grid lighting in remote areas, all the way through to multi-megawatt utility-scale power stations.”

That scalability and a consistent reduction in manufacturing costs has underpinned what he describes as a “phenomenal” expansion. Solar PV is now, in many cases, the cheapest form of electricity generation at utility scale—a position it had already reached even before recent volatility in fossil fuel markets. Last year marked a milestone: globally, new renewable capacity met the entire increase in electricity demand. “It’s the first time we didn’t need to add fossil fuels just to meet demand growth,” Sample notes. “That’s a big turning point.”

If cost has driven adoption, standards have played an equally critical enabling role. IEC TC 82 oversees one of the largest work programmes in the organization, with around 93 active projects. Many of these are adapting existing frameworks for measurement, performance, and reliability to emerging technologies and applications.

Tech for improved solar cells

One of the problems with silicon modules, which are used in most PV panels, is their relatively low energy efficiency. However, the technology has improved and energy efficiency gains have been made over the years, notably with the manufacturing of bigger cells and even bifacial modules. One of the most closely watched developments is perovskite solar cells which, pundits claim, offer significant improvements in power conversion efficiency. However, some challenges must still be overcome. “The problem with perovskites is that they are metastable,” Sample explains. “Their performance changes depending on exposure to light and dark conditions. That makes standardized measurement difficult.”

This has always been a point of tension in the solar PV industry. Manufacturers aim to maximize performance claims within tolerance limits, while users may find that the actual output is slightly lower in real-world conditions. With perovskites, the problem is magnified by their fluctuating performance.

“Ultimately, customers want to know how much power a system will produce,” Sample says.  “So, we must define a standard stabilization method-essentially deciding when and how to measure performance so results are both repeatable and representative of actual operation. We’ve addressed similar issues before with other thin-film technologies like cadmium telluride and copper indium gallium selenide (CIGS), which also exhibit metastability.”

What IEC Standards?

The IEC has multiple work items addressing both performance measurement and reliability of single junction perovskite and tandem (or multi-junction) perovskite. A project is at committee draft stage and may advance this year, though Sample is quick to point out that IEC is expected to facilitate trade, not research. “Until you have a commercial product, we shouldn’t really be working on the standard,” he says. “But we try to push the boundaries.”

To bridge that gap, the IEC recently published a technical report, IEC 60904-14, summarizing existing approaches and is now working to adapt its IEC 60904 series for perovskite measurement.

Other technology performance increases are being developed for conventional crystalline silicon. There has been a move from traditional p-type to n-type doping of silicon in PV cells, as manufacturers look for higher efficiency. According to Sample, this has led to some issues of ultraviolet degradation occurring in the field. IEC TC 82 is developing a UV-ID test to calibrate the risk of performance loss in some of these technologies.

New demands are driving tech advances

Alongside materials, new applications are also driving change. Floating solar installations have already been deployed at scale, including in the UK, often in the absence of dedicated standards (which is typical for emerging technologies). In the early stages, developers relied on existing guidelines, sometimes extending test conditions, to approximate real-world stresses. “Now, we’re developing standards specifically for floating PV systems, covering both system design and component-level testing,” Sample says. “The challenges are considerable.”

Floating arrays operate in marine environments, which means they are exposed to high humidity with constant motion introducing mechanical stresses not seen in fixed or even solar PV tracking systems. Cable management becomes critical, as poorly designed systems risk submersion or water ingress. 

Higher voltage DC and hybrid systems

The industry is also exploring a shift from 1500 Volts (V) to 2000 V direct current (DC) systems and potentially 3000 V in utility-scale installations. Higher DC voltages reduce resistive losses in cables, potentially improving overall energy efficiency. However, such a shift requires a comprehensive overhaul of standards across modules, connectors, inverters, and grid integration. This long-term endeavour is only just beginning.

Hybrid energy systems are another growing focus, particularly in off-grid regions, which is the focus of another IEC TC 82 working group. These systems combine solar with other generation sources such as diesel, wind, or micro-hydro, alongside battery storage.

The challenge is that demands evolve rapidly. Sample explains: “When communities gain access to electricity, usage increases—from lighting and phone charging to refrigeration and entertainment. Standards must account for these dynamic loads, as well as system reliability and user behaviour, such as bypassing battery protections, which can damage systems.”

Meeting the recycling challenge

With solar panels having a 25-year lifespan, as soon as 2030, there could be 8 million tonnes of decommissioned solar panels worldwide. By 2050, end-of-life PV waste is expected to reach 78 million tonnes, posing a major environmental challenge without effective recycling.

In Europe, there are established schemes like PV Cycle, where manufacturers contribute to recycling costs upfront. However, most recycling today is based on weight. “That means it’s easy to meet targets by recycling aluminium frames, cables, and glass,” Sample says. “The difficult part is the module itself.” Solar panels are designed for durability (sealed, layered structures that resist environmental degradation). Separating those layers to recover high-value materials like silicon and silver is technically possible, but rarely economical.

Most current processes rely on mechanical crushing, producing materials that are reused in lower-value applications such as road aggregate or insulation. “You can meet a 95% recycling target by weight without recovering the most valuable materials,” he notes.

Scale is another barrier. While large volumes of panels are reaching end-of-life, they are geographically dispersed. Specialized recycling facilities are limited, and transport costs further complicate the economics.  The IEC is working on a publicly available specification for the reuse of PV modules and the circular economy IEC PAS 63525 ED1. The IEC is also working on a new standard, IEC 63395, for the systematic, sustainable management of e-waste. One of the standard’s objectives is to restrict operators who do not comply with the  requirements.

Where certification helps

Ensuring that manufacturers meet the requirements established in the standards mentioned above is what the IEC Conformity Assessment Systems have been established for. IECEE, the IEC System of Conformity Assessment (CA) Schemes for Electrotechnical Equipment and Components, addresses 23 different product categories, including solar PV parts and modules. Its certificates ensure that solar panels meet the performance and safety levels specified by standards. They are widely used in the solar PV export industry.

Through its IEC Quality Assessment System (IECQ), IEC operates an international ecodesign certification scheme for incorporating impact on the environment in product design, in accordance with the international standard for ecodesign IEC 62430.  This is also a tool that can be used to reduce e-waste.

Solar PV is already a critical element in the transition to sustainable energy generation. IEC work aims to ensure that the entire PV lifecycle, from development to deployment and ultimately to end of life, is also sustainable.