An international research team has developed an index -based teledentment method to see trends in the global development of water -based PV. It has established that China is currently good for 80% of the worldwide total capacity used.
A research group led by scientists from Chinese Tianjin Normal University has used satellite images to reveal the rapid development of global water -based PV (WPV) in the past 20 years.
WPV consists of both floating PV systems and photovoltaic plants that are used on fixed structures in shallow water.
For the task, the team has developed an index -based external detection method, which they called the normalized difference with photovoltaic index (NDPI). Index-based methods are mathematical formulas that identify land functions based on spectral indices, which are calculated using different tires of light recorded by satellites.
“In comparison with traditional threshold and machine learning approaches, index-based methods are based on the universal characteristics of target objects, offering greater adaptability to variations in environmental conditions,” the academics said. “Moreover, index-based methods offer faster and more flexible solutions for WPV Mapping and information updates, because they respond directly to the spectral characteristics of the target objects. Moreover, WPV arrays, usually on water surfaces, show lower sensitivity to environmental disorders compared to terrestrial PVE and energy-first.”
To create their NDPI method, the researchers analyzed 5000 sites worldwide from Google Earth. The samples were divided into five land cover types, namely bare soil, impenetrable surface, vegetation, water and PV. Based on the analysis of the images, solar panels reflect more shortwave infrared (SWIR1) light than most surfaces and reflect less visible light and near infrared (NIR) than land or water.
After these discoveries, the team was able to design formulas that detected solar panels on water. The method was subsequently verified over 1,000 WPV and accuracy (among others) for spatial distribution and installation date of 0.935 and 0.927 respectively. “In general, the WPV installation data showed high accuracy, with the accuracy of the user (UA), the accuracy of the producer (PA) and F-score values of more than 0.9 for all years except 2012 and 2013,” they said.
As the method was verified, the scientists tested it on 2023 images of the Sentinel-2 MSI satellite sensor managed by the European Space Agency (ESA). With the help of 2000-2023 Images of NASA’s Landsat satellite, the team tested the NDPI on trends in the installation date.
“The global WPV area reached 589.14 km2 in 2023 in particular. In particular, the growth of the global WPV accelerated considerably after 2015, with an annual growth rate of 56.06 km2 JR-1, almost ten times that of the period 2000-2015 (5.98 km2 YR-18),” the results. “WPV development is particularly fast in Asia, mainly driven by China. In 2023 the WPV area in China reached 472.92 km2, good for more than 80% of the worldwide total.”
The analysis showed that Asia makes the primary contribution to the global WPV, accounting for more than 97%of the WPV area, followed by North America with 1,569%, while all other continents had a combined contribution of around 1%. While China made the dominant contribution, with a WPV area of 472.92 km2, Thailand and Vietnam came forward as important areas with areas of more than 20 km2 in each.
“In China, policy support has accelerated the WPV development in particular, whereby the WPV area is increasing from 104.89 km2 in 2016 to 472.92 km2 against 2023,” they noticed. “Apart from China, the WPV area in Vietnam also rose from 6.17 km2 in 2017 to 24.24 km2 in 2023 in 2023, and the WPV area in Thailand almost tripled from the previous year to 2023. In Europe and North America, WPV areas also show an upward trend between 2005 and 2005.” “”
By taking out their research, the team said that it was the global installed capacity of WPV estimates at 21.18 GW, with projections that suggest that it could reach 35.64 GW by 2030.
The findings were presented in “In the past 20 years, satellite images have been revealing a rapid development of water -based photovoltaic worldwidePublished in the International Journal of Applied Earth Observation and Geod formation.
Scientists from Chinese Tianjin Normal University, Henan University of Technology, Advanced Laser Technology Laboratory of the province of Anhui, Fujian Agricultural and Forestry University, Zhejiang University and Finland’s National Survey of Finland participated in the research project.
This content is protected by copyright and may not be reused. If you want to work with us and reuse part of our content, please contact: editors@pv-magazine.com.
