Researchers in Brazil have developed a weighted methodology for PV inverter efficiency that takes into account country-specific solar radiation and operating conditions. The approach is designed to address the limitations of international metrics by incorporating variables such as input voltage and maximum power point tracking (MPPT) performance.
A recent study conducted in Brazil proposes a new approach for evaluating the efficiency of grid-connected photovoltaic inverters. The methodology is based on the observation that commonly used weighted efficiency models do not adequately reflect the climatic and operational conditions of a specific country.
Conventional metrics, such as European efficiency and the California Energy Commission (CEC) standard, are based on weighting coefficients derived from irradiance profiles in other regions, which can distort performance comparisons when applied in Brazil.
The proposed approach introduces a new weighted efficiency formulation based on representative solar radiation data for the country. This takes into account the fact that inverters operate at varying load levels throughout the day and year, which directly affects their average efficiency. Unlike conventional methods, the new model adjusts the weighting assigned to each operating range to better reflect Brazil’s solar generation profile.
In addition to climate-specific adjustments, the methodology includes technical parameters not typically included in standard metrics, such as efficiency dependence on input voltage, Maximum Power Point Tracking (MPPT) performance, and efficiency variation under different load conditions. This allows a more comprehensive assessment of the inverter’s performance under real operating scenarios.
The authors note that applying foreign metrics can lead to inaccurate performance assessments, especially in countries with high solar radiation and different load profiles such as Brazil. Because inverters do not operate at maximum efficiency all the time, weighted averages are essential for showing performance over time. However, if these weights are not adapted to local conditions, they may not reflect actual system behavior.
The researchers say the methodology could support improved certification, labeling and benchmarking of inverters in Brazil, especially as distributed generation and utility-scale solar deployment continue to grow. By providing a benchmark tailored to national conditions, the approach can help optimize equipment selection, with potential benefits to system efficiency and project returns.
The new model was presented in the study “Development of weighted efficiency for photovoltaic inverters: a Brazilian case study,” published in Advances in solar energy. The research was conducted by a team from the State University of Campinas (UNICAMP), with a focus on adapting performance metrics to the operational and climatic conditions in Brazil.
This content is copyrighted and may not be reused. If you would like to collaborate with us and reuse some of our content, please contact: editors@pv-magazine.com.
