The current industrial production of hydrogen basically comes from fossil energy. Under the background of carbon emissions peak, the utilization of hydrogen energy has to be greener and more convenient .The production of hydrogen from abundant seawater resources seems to be a promising way. This paper reviews the research and development status of hydrogen production from seawater in China and abroad in recent years, and summarizes the overall research progress of hydrogen production by direct electrolysis and photolysis of seawater respectively. Then, it introduces the industry development status of hydrogen production from desalinated seawater. Finally, the future development of hydrogen production from seawater is prospected. It is discovered that great challenges exist since direct hydrogen production of seawater is still in R&D and test stage. The hydrogen production from desalinated seawater need to resolve problems in complex process through industrial demonstration. The future of hydrogen production from seawater is based on hydrogen demand, electricity cost and technical feasibility. Under certain circumstances, hydrogen production from seawater may usher in development opportunities.

Joe Biden, as the new president of the United States, attaches great importance to climate change and sets out an ambitious "clean energy revolution plan" to deal with the climate crisis, announcing to return to the Paris climate agreement to ensure that the United States will achieve carbon neutrality by 2050. This paper interprets the key points of Biden's "clean energy revolution plan" and its climate policy propositions, and makes a retrospective analysis of the development history of American energy policy to probe deeply into the Biden administration's climate and energy propositions. In terms of energy policy, the study found that Biden continues the consistent position and proposition of the Democratic Party to support clean energy revolution, holding the same basic position with the Obama era, but there are important changes in two aspects: First, the United States has achieve energy independence, which will bring more wiggle room for the Biden government and subsequent governments to make domestic and foreign policy choices, and its strategic means will be less restricted by energy factors; Second, the Biden government will pay more attention to the core role of clean energy technology innovation, with the help of the source innovation advantage and scientific and technology leadership of the United States, lead the formulation of a new set of rules of the game, reform the international energy governance system under the new situation, firmly control the international discourse power to obtain the maximum benefits, and further strengthen the use of scientific and technological advantages to suppress major competitors. Then, this paper analyzes its influence on the world energy pattern and the future development of China, which mainly includes: 1) the differences in the cognition and behavior of climate change will cause future Sino-US frictions; 2) wariness of China will intensify competition between the United States and China in climate-related innovative technologies; 3) the U.S. may form a coalition of "democratic countries" to continuously exert pressure on China. In view of this, some policy suggestions for China are put forward: According to the new development pattern of "Dual Circulation", China should accelerate the independent innovation and application of key technologies of clean energy; accelerate the establishment of national independent innovation demonstration zone for multi-energy integration, and contribute solutions to China's goal of achieving carbon peak and carbon neutral; deeply integrate digital technology and energy technology to build China's smart energy system; deeply participate in global cooperation, and actively participate in international energy cooperation The reform of energy source management system will create a good external environment for China's energy transformation; opening a new model of cooperation between China and the United States and share responsibilities to lead the global transition to green and low-carbon energy and combat climate change.

The global energy is developing towards low-carbon and clean, hydrogen, as an efficient, clean energy and an ideal energy interconnection medium, has a wide range of application scenarios and is recognized to play a pivotal role in the process of energy transformation. The development trend of global hydrogen production technology is studied from the perspective of patent analysis. It is found that the research and development speed of electrolytic water hydrogen production technology is far ahead of that of fossil fuel hydrogen production technology in recent 10 years, and there is further growth potential in the future. Research on electrolytic water technology focuses on proton exchange membrane electrolytic water (PEM) technology and the design of electrolytic cell, control technology and power system design technology for matching renewable energy power. The United States and Japan are the major exporting countries of PEM electrolytic water technology. The existing technology systems in these regions are relatively mature and the technology monopoly degree in the industry is relatively high. The research of PEM electrolytic water technology in China is at the growth stage, the research, development and innovation are still primarily conducted by universities and research institutes, and the innovation achievements have not yet fully entered the market.

The paper selects the EU’s wind energy research projects in Horizon 2020, establishes a wind energy industry custom dictionary and utilizes natural language processing (NLP) methods to extract project keywords. Using bibliometrics methods and visualization tools, knowledge maps are drawn, and project theme clustering, research hotspots and development trends, etc., are analyzed. It is found that the hot themes of the projects include ICT, rotor and blade structure, innovative concept design models for wind turbine, and many other wind energy related technologies such as electrical, control, sensing, detection, wind resources and site selection, robot operation and maintenance etc. Since 2018, wind energy research themes such as digital transformation, digital maps, satellite image, marine robots, mooring system, and predictive maintenance have received more attention. The EU wind energy industry has formed a wind energy innovation ecosystem, with SIEMENS, DANMARKS TEKNISKE UNIVERSITET, TECHNISCHE UNIVERSITEIT DELFT, FRAUNHOFER, KATHOLIEKE UNIVERSITEIT LEUVEN as the core. In the context of the "carbon peak and carbon neutrality" goal, China's wind energy industry will embrace larger development opportunities. In the end, this article puts forward suggestions on strengthening innovation cooperation with the EU's wind energy industry, expanding the coverage of innovation content, stimulating the innovation vitality of SMEs, and nourishing the innovation ecosystem of China's wind energy industry.

Reliable greenhouse gas (GHG) monitoring is conducive to the improvement of the carbon accounting system and will promote the development of the carbon emission trading market, providing scientific monitoring support for the realization of double carbon goals. This study reviews the spatial distribution, research hotspots, and evolution of academic research and patent technology in the field of international GHG monitoring based on bibliometric and patent analysis. Through comparative analysis, the research hotspots were classified into research and application of monitoring technology and instruments, GHG monitoring and emission estimation in urban areas, application of monitoring technology in key industries such as industry, global and regional-scale flux monitoring and its supporting technologies, and monitoring management methods, means, and measures. The research evolution is characterized by the gradual improvement of monitoring methods, technologies, and instruments, the gradual expansion of monitoring fields and scope, the continuous upgrading of monitoring platforms, and the continuous innovation of monitoring management. Combined with the international development trends and domestic status, there are still key technical problems, monitoring accuracy problems, and management system and management mechanism challenges in our country. Some suggestions were put forward around tamping the GHG monitoring foundation, improving the GHG stereo monitoring and evaluation system, and making innovations in management systems and management mechanisms.

Policy coordination is a crucial foundation for ensuring and promoting the healthy and sustainable development of industries.This paper takes 868 hydrogen energy-related policies in China as the research object,designing a policy coordination measurement framework that includes two dimensions-time and space-and three elements:policy actors,instruments,and themes.Using deep learning and grey relational analysis,the study quantifies the coordination of China’s hydrogen energy policies.The findings indicate that,in the time dimension,the network of cooperation among policy actors in China’s hydrogen energy sector is expanding,and the degree of coordination continues to improve.However,the coordination of policy instruments has slightly decreased,with a preference for pilot demonstrations and regulatory standards over tools like government procurement and tax incentives.The coordination of policy themes is at an upper-middle level and continues to improve,though policy support for hydrogen production,storage,transportation,and refueling still needs enhancement.In the spatial dimension,the coordination of actors at the central government level is significantly higher than in other hydrogen energy industrial clusters,while the coordination of themes is at a lower-middle level,notably below that of other clusters.The use of policy instruments by the central government and hydrogen energy industrial clusters is similar,with little difference in instrument coordination.Moving forward,efforts should focus on establishing cross-regional policy coordination frameworks and communication platforms,optimizing the combination of policy instruments,and promoting the development of upstream and midstream segments of the hydrogen energy industry for coordinated optimization.