Amid record-low solar panel prices, the focus of cost reduction for utility-scale solar projects is shifting to non-module balance-of-system (BoS) costs. The transition from 1.5 kV voltage to 2 kV in solar projects is expected to gain momentum until 2030.
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The reason for switching from 1.5 kV voltage to 2 kV in solar projects is based on electrical principles, specifically the relationship between electrical power (P), current (I) and voltage (V) – expressed as P= IV. By increasing the voltage while keeping the current constant, the output power can be increased without additional losses. This transition is expected to result in an increase in energy yield for PV locations by 0.5% to 0.8%.
Higher voltages are suitable for longer module strings. A 1.5 kV system can accommodate 33 modules rated at 45 V DC, while a 2 kV system can accommodate 44 modules – representing a 33% increase in power capacity. A longer string length means fewer strings. This reduces the electrical balance of system expenses, including costs for combiner boxes, connectors and cabling, by 10% to 15%. The number of inverters required should also decrease, as higher voltages accommodate more power-dense electronics.
Although 2 kV inverters are more expensive due to the smaller production scale of some components and increased testing requirements, the long-term prospects are still positive. Switching to 2 kV will give the inverters greater power density, saving on housings, fuses and other components. Fewer components on solar projects should reduce labor costs and mean lower operation and maintenance (O&M) costs. That could ultimately mean 1% to 2% lower capital costs, plus higher energy yield.
Main challenges
Several challenges must be addressed before widespread adoption can occur. The main bottleneck is the availability of 2 kV inverters, as numerous technical challenges need to be solved. Currently, components that can handle 2 kV are limited and inverter manufacturers face issues related to combiner boxes, external insulation, fuses and switches. A significant amount of hardware and software testing must be performed to ensure the reliability and safe operation of 2 kV inverters on the power grid. There are also greater challenges associated with adopting 2 kV for utility-scale string inverters than for central inverters, due to the former’s higher power density. This may slightly delay the adoption of 2 kV string inverters compared to central devices.
The limited availability of standards is another major barrier hindering the development and adoption of 2 kV products. Recently, JinkoSolar Holding Co. Ltd. the first solar panel company to receive certification from UL Solutions Inc. for its 2 kV modules. However, it will take some time for fully developed certification processes to emerge and even longer for manufacturers to adapt their products to these standards. Convincing developers to invest in 2 kV projects poses another challenge, as these new locations will be inherently riskier than standard 1.5 kV projects, with higher costs and a smaller selection of suppliers.
For modules, the increased voltage requires greater creepage distance between electrical components, which can somewhat reduce a module’s efficiency and increase its cost per watt. Furthermore, module manufacturers are currently focused on the shift to n-type technology, coupled with tight margins due to an oversupply of panels, reducing their willingness to invest in new technology. However, the transition to 2 kV is not particularly difficult for modules, compared to the challenges faced by inverter manufacturers, as most large commercial and large-scale PV modules already use a glass-glass structure, which provides sufficient insulation and protection for higher voltages .
Technology forecast
China and the United States will likely be the first regions to adopt 2 kV technology. China serves as a testing ground for the world’s largest utility-scale manufacturers and is expected to undertake numerous pilot projects to ensure component reliability before manufacturers expand into international markets. The faster lead times in China will also enable faster market access for 2 kV products. The United States is expected to follow suit, with GE Vernova recently launching a 2 kV inverter, marking a significant step into the market.
It will take some time for developers and engineering, procurement and construction companies to become accustomed to 2 kV products, as well as longer timelines for investment decisions in the United States. Based on the historical precedent of the shift from 1 kV to 1.5 kV, with deliveries of 1.5 kV inverters booming two years after the first pilots, the wider adoption of 2 kV technology is expected to will take several years. S&P Global predicts that 2 kV products will grow from less than 5 GW in 2026 to 380 GW in 2030, accounting for 77% of large-scale solar projects worldwide by then.
The shift to 2 kV offers a promising opportunity for long-term reductions in system balance, inverter, labor and O&M costs, thanks to simpler site layouts and small increases in energy yield. Industry-wide collaboration is essential to overcome technical challenges, set standards and drive adoption. Growing awareness of this technology leap is critical to identifying additional cost savings across the entire balance sheet of systems. While technical challenges remain, particularly in the design of 2 kV inverter products, S&P predicts that utility-scale solar will begin to transition to 2 kV between 2026 and 2027, especially in the United States and China.
About the authors: Liam Coman is a solar research analyst at S&P Global Commodity Insights, covering the solar, balance-of-system and energy storage inverter supply chains. Coman works with suppliers to analyze trends, make forecasts and assess the solar inverter industry. He previously worked for an engineering firm specializing in environmental regulations and policy compliance.
Siqi He is a principal analyst on S&P Global Commodity Insights’ clean energy technology team, responsible for PV, energy storage inverters and solar supply chain research. She previously worked for Wood Mackenzie Power & Renewables in New York and spent four years as a financial analyst at PetroChina in Beijing.
Karl Melkonyan is a Lead Analyst in the Clean Energy Technology team, specializing in energy and renewable energy market research and analysis, particularly for PV markets and solar companies. His focus includes financial analysis, manufacturing technology and materials, and the trends and requirements of the PV industry.
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