Wind and solar energy resources assessment service

(1) The high-resolution data set of wind energy resources

The BCC has a national climate average 1 km resolution wind energy resource database (Figure 1). The 1km resolution wind energy resource database is the main research result of the fourth national detailed investigation and evaluation of wind energy resources. The database covers the whole Chinese region and contains the major wind resource elements. It is mainly made based on WERAS/CMA, a numerical simulation and evaluation system for wind energy resources independently developed by China Meteorological Administration. Its basic idea is that considering the near surface wind speed distribution is the result of weather system and local terrain on the basis of atmospheric boundary layer dynamics and thermodynamics, and the change of wind speed distribution is caused by the weather system movement and change, and atmospheric boundary layer has obvious diurnal changes, and maximum mixing layer thickness is related to the nature of the weather system. Therefore, according to the wind direction, wind speed and the height (850 hPa or 700 hPa), the historical weather in the assessment area is classified, and then 5% of the samples are randomly selected as the typical day of the numerical simulation of each typical day. Finally, the average climate distribution of wind energy resources is obtained according to the frequency of various weather types.

Figure1. Annual average wind speed map at 100 meters in China

The BCC also has a national long-term, 3 resolution hourly wind energy resource database. It provides hourly estimates of a large number of atmospheric and land climate variables covering the period from January 1995 to 2017, and contains wind speed, wind direction, air density, temperature, relative humidity, air density, wind power parameters, available hours, global horizontal irradiance and other derivatives. It covers an area of more than 25 million square kilometers on a 3km grid, including the whole China and "Belt and Road" major countries, and resolves the lower atmosphere using 10m from the surface up to a height of 200m. The dataset has passed strict quality inspection and expert review. It has been widely purchased in many times by well-known enterprises and institutions and applied in the survey of wind resources, site selection of wind resources and other fields.

(2) The high-resolution data set of solar energy resources

Based on the multi-source meteorological satellite data, the BCC has developed the solar radiation remote sensing inversion algorithm and deep learning algorithm, and constructed the first set of high spatial-temporal resolution solar resource data set (5 km×5 km, hourly, 2000-2022, including horizontal total radiation, direct radiation, scattered radiation and other elements) in China (Figure 2). The test of measured data shows that the overall error of the data is within 5%. This data set provided technical services to four energy and power enterprises and won the first prize of China Geographic Information Industry Association.

Figure2. Spatial distribution map of global horizontal irradiation in China

(3) The new energy big data platform

In recent years, various types of new energy data from the NCC have been developed into application systems, providing assistance to many new energy development enterprises in the rational and efficient use of clearn energy. Currently, it has integrated land wind resources, land solar resources, ocean wind resources, typhoon data, and real-time and forecast data, achieving various functions such as query, analysis, and data management. Based on the actual business needs of each partner, we have customized and developed some unique functions for each partner, including wind tower management and data query, wind farm site selection, automatic wind turbine layout, and survey management. For the moment, these systems are providing assistance to thousands of direct and indirect users in the utilization of new energy.

We have customized and developed new energy data application systems for major enterprises.We can implement efficient, convenient and accurate checking, finding and assessment of wind and solar resource, provides authoritative data for the macro-siting and micro-siting; provides meteorological disasters queries for the farm including extreme temperature, sand and dust, thunderstorms, freezing, heavy rain, extreme wind speed, etc. in the past 30 years, and provides supporting of the coordinated matching of wind turbine selection and wind power climate environment analysis. In addition,these systems also can provide the capabilities of land and offshore wind resource display, weather and ocean forecast, wind farm historical typhoon queries and analysis, evaluation of developable capacity in given area, wind farm economic evaluation, macro and micro analysis of site selection, On-site survey tracking via mobile application, road planning and design of firm and other system managements.

After years of deep cultivation in the field of new energy, we are currently mainly divided into two major sectors in the application of wind resources and photovoltaic resources, as shown in the following figure 3.They are the research and development of new energy data and the development of new energy data application systems. In terms of data research and development, it not only includes the research and development of natural resource data such as wind resource data, solar resource data, typhoon data, but also provides weather conditions and forecasts, tidal forecasts, etc. In addition, various business data and wind tower data will also be collected and organized. In terms of system functions, we provide various statistical analysis and query functions, including macro analysis, micro analysis, and exploitable quantity analysis. Provide weather conditions and forecasts for designated areas in the system, as well as real-time and historical typhoon queries.

This new energy big data platform is equipped with functions such as wind and solar energy resource assessment, macro-sitting for wind farms and solar PV stations, economic evaluation of wind farms and solar PV stations, and energy power security prediction and early warning. The platform has provided services to nearly 20 energy and power enterprises.

(4) Renewable energy planning

Based on the high spatiotemporal resolution wind-solar resource database, the BCC conducted a GIS-based assessment of the technical-economic exploitable potential of wind and photovoltaic energy on both global and national scales (Figure 4 and Figure 5). The outcomes of these researches have been applied in reports such as the "Earth Big Data Supporting Sustainable Development Goals Report 2023" by the Chinese Academy of Sciences and the "Strategic Research on China's Energy Resource Endowment and Energy Security" by the Chinese Academy of Engineering.

The BCC has developed spatiotemporal complementary technology for wind and solar power generation, and has created the optimal allocation map for new energy development in China. The relevant research outcomes have been applied to the planning of "14th Five-Year Plan" new energy mega bases by the National Development and Reform Commission and the National Energy Administration.

The BCC has developed a novel analysis technique for power system multi-temporal scale electricity quantity balance based on high-resolution meteorological data. This technique unveils the optimal layout for wind-solar development in China under carbon neutrality targets (Figure 6 and Figure 7). The outcomes of this research have been applied in the "Research on the Development Path of China's Wind Power Industry" by the China Wind Energy Association.

Fig6. Optimal layout of wind power development in China under regional grid interconnection scenario

Fig7. Optimal layout of solar photovoltaic development in China under regional grid interconnection scenario

The BCC has developed a synergistic optimization model for wind-solar-storage systems, revealing the developmental path of "new energy + energy storage" under carbon neutrality goals. The outcomes of this research have been applied in the formulation of the "14th Five-Year Plan" energy storage development plan and the medium- to long-term energy storage development strategy of the State Grid Corporation of China (Figure 8).

Wind and solar energy resources prediction service

Since April 2022, the National Climate Centre (NCC) has released monthly forecast products for national wind and solar energy resources to the public, marking that China has the climate prediction capability for wind and solar energy resources. Relying on integrated climate operation platform, NCC has established an operational system to support the monitoring, diagnosing and prediction of wind and solar energy, and obtained the corresponding software copyright. The released products include comprehensive prediction products and objective model prediction products, consisting of the text and graphic documents and raw forecast data of 100 m wind speed, downward solar radiation, and year-on-year analysis for the next month.

Fig.1 The sample graphs included in the monthly wind energy resources forecast products by NCC.
Left: the comprehensive forecast map of anomalous percentage of 100m wind speed in the next month;
middle: the spatial distribution of predicted original 100m wind speed;
right: the spatial distribution of predicted year-on-year difference percentage of 100m wind speed.

Fig.2 The sample graphs included in the monthly solar energy resources forecast products by NCC.
Left: the comprehensive forecast map of anomalous percentage of surface total shortwave radiation in the next month;
middle: the spatial distribution of predicted original surface total shortwave radiation;
right: the spatial distribution of predicted year-on-year difference percentage of surface total shortwave radiation.

Fig.3 Interactive system modules in NCC’s integrated climate operation platform.
PartⅠ, PartⅡand Part Ⅲ show the monitoring, diagnosing and prediction function module of wind/solar energy resources, respectively.

Fig.4 The technical scheme of forecasting method based on dynamic models and key influencing factors for the sub-seasonal prediction of wind and solar energy resources.

In recent years, the installed renewable power capacity in China, wind power generation and photovoltaic power generation primarily, continues to rise. However, global climate change and increasing extreme weather will bring major risks to energy supply, energy security and many other links. In the face of the impact of climate change on the energy system, short-term weather forecast and mid-and-long term climate forecast service become urgent. At the end of 2021, the National Energy Administration and the China Meteorological Administration signed a strategic cooperation framework agreement, aiming to give full play to the advantages of policy coordination and resource complementarily, establish a smoother and more efficient working exchange mechanism, make full use of accurate meteorological forecast information, and improve energy production and supply level.

The mid-and-long term wind and solar energy resources prediction products released by NCC fill a market vacancy of meteorological energy service in China. The prediction products can give the nationwide distribution of wind and solar energy resources in the future for a long time in advance, which can significantly improve the security of national electricity grid and the meteorological guarantee ability of energy security. At the same time, they can also provide service for energy and power enterprises by guiding the spot and mid-and-long term transactions of new energy power in some provinces.