Assessment of wind and photovoltaic power potential in China

Decarbonization of the energy system is the key to China’s goal of achieving carbon neutrality by 2060.However,the potential of wind and photovoltaic(PV)to power China remains unclear,hindering the holistic layout of the renewable energy development plan.Here,we used the wind and PV power generation potential assessment system based on the Geographic Information Systems(GIS)method to investigate the wind and PV power generation potential in China.Firstly,the high spatial-temporal resolution climate data and the mainstream wind turbines and PV modules,were used to assess the theoretical wind and PV power generation.Then,the technical,policy and economic(i.e.,theoretical power generation)constraints for wind and PV energy development were comprehensively considered to evaluate the wind and solar PV power generation potential of China in 2020.The results showed that,under the current technological level,the wind and PV installed capacity potential of China is about 56.55 billion kW,which is approximately 9 times of those required under the carbon neutral scenario.The wind and PV power generation potential of China is about 95.84 PWh,which is approximately 13 times the electricity demand of China in 2020.The rich areas of wind power generation are mainly distributed in the western,northern,and coastal provinces of China.While the rich areas of PV power generation are mainly distributed in western and northern China.Besides,the degree of tapping wind and PV potential in China is not high,and the installed capacity of most provinces in China accounted for no more than 1%of the capacity potential,especially in the wind and PV potential-rich areas.

Advances,challenges,and perspectives for CCUS source-sink matching models under carbon neutrality target

With the widespread popularity of carbon neutrality,the decarbonization approach using carbon capture,utilization,and storage(CCUS)has grown from a low-carbon utilization technology to an indispensable technology for the entire global carbon-neutral technology system.As a primary method to support CCUS research,source-sink matching models face several new demand-oriented challenges.Comprehensive research and in-depth insights are needed to guide targeted capability upgrades.This review evaluates the advances,challenges,and perspectives of various CCUS source-sink matching models developed in the past 10 years.We provide an integrated conceptual framework from six key attributes relating to mitigation targets,carbon sources,carbon sinks,transportation networks,utilization,and integration(synergy).The results indicate that previous models have effectively deepened our understanding of the matching process by targeting various CCUS-related issues and provided a solid foundation for more robust models to be developed.Six perspectives are put forward to outline research and development prospects for future models,which may have meaningful effects for advancement under emerging carbon neutrality targets.

Technical pathways of dual carbon control in China’s buildings sector

Reducing carbon emissions in the buildings sector is of great significance to the realization of China’s carbon peak and neutrality goals.By analyzing factors influencing buildings carbon emissions at the operational stage,this paper applies the China Building Carbon Emission Model(CBCEM)to make medium and long-term forecasts of China’s building operation carbon emissions,discussing the goals and realization paths of China’s dual carbon goals in the buildings sector.The results show that building operation carbon emissions,according to the current development model in the buildings sector,will peak in 2038-2040 with a peak carbon emission of about 3.15 billion tons of CO_(2);however,by 2060,carbon emissions will still be 2.72 billion tons of CO_(2),falling short of China’s dual carbon goals.The carbon saving effects of three scenarios,namely clean grid priority,building photovoltaic priority and energy efficiency enhancement priority,were measured and shown to be significant in all three scenarios,but the building photovoltaic priority and energy efficiency enhancement priority scenarios were superior in comparison.

Several key issues for CCUS development in China targeting carbon neutrality

Carbon capture,utilization,and storage(CCUS),as a technology with large-scale emission reduction potential,has been widely developed all over the world.In China,CCUS development achieved fruitful outcomes.CCUS gained further broad attention from the announcement of the carbon neutrality target by 2060,as CCUS is an indispensable important technology to realize carbon neutrality.It helps not only to build zero-emission and more resilient energy and industry systems but also provides negative emission potential.This paper discusses the new demand for carbon capture,utilization,and storage development brought by the carbon neutrality target analyzes the development status.As there remain various challenges of CCUS development,this paper focuses on several key issues for CCUS development in China targeting carbon neutrality:1)how to reposition the role of CCUS under the carbon neutral target?2)how shall we understand the technology development status and the costs?3)what role shall utilization and storage play in future?4)potential strategy applied to solve challenges of source-sink mismatch and resources constraints;and 5)new business model that suits large scale deployment of CCUS.This paper puts forward several policy suggestions that should be focused on now in China,especially to raise awareness under the vision of carbon neutrality that the role and contribution of CCUS are different,to accelerate the establishment of a comprehensive and systematic enabling environment for CCUS.

The role of heat pump in heating decarbonization for China carbon neutrality

Heating decarbonization is a major challenge for China to meet its 2060 carbon neutral commitment,yet most existing studies on China’s carbon neutrality focus on supply side(e.g.,grid decarbonization,zero-carbon fuel)rather than demand side(e.g.,heating and cooling in buildings and industry).In terms of end use energy consumption,heating and cooling accounts for 50% of the total energy consumption,and heat pumps would be an effective driver for heating decarbonization along with the decarbonization on power generation side.Previous study has discussed the underestimated role of the heat pump in achieving China’s goal of carbon neutrality by 2060.In this paper,various investigation and assessments on heat pumps from research to applications are presented.The maximum decarbonization potential from heat pump in a carbon neutral China future could reach around 1532Mton and 670Mton for buildings and industrial heating respectively,which show nearly 2 billion tons CO_(2) emission reduction,20% current CO_(2) emission in China.Moreover,a region-specific technology roadmap for heat pump development in China is suggested.With collaborated efforts from government incentive,technology R&D,and market regulation,heat pump could play a significant role in China’s 2060 carbon neutrality.

Technological innovations on direct carbon mitigation by ordered energy conversion and full resource utilization

Coal consumption leads to over 15 billion tons of global CO_(2) emissions annually,which will continue at a considerable intensity in the foreseeable future.To remove the huge amount of CO_(2),a practically feasible way of direct carbon mitigation,instead of capturing that from dilute tail gases,should be developed;as intended,we developed two innovative supporting technologies,of which the status,strengths,applications,and perspective are discussed in this paper.One is supercritical water gasification-based coal/biomass utilization technology,which orderly converts chemical energy of coal and low-grade heat into hydrogen energy,and can achieve poly-generation of steam,heat,hydrogen,power,pure CO_(2),and minerals.The other one is the renewables-powered CO_(2) reduction techniques,which uses CO_(2) as the resource for carbon-based fuel production.When combining the above two technical loops,one can achieve a full resource utilization and zero CO_(2) emission,making it a practically feasible way for China and global countries to achieve carbon neutrality while creating substantial domestic benefits of economic growth,competitiveness,well-beings,and new industries.

Calcium-looping based energy conversion and storage for carbon neutrality-the way forward

With the global ambition of moving towards carbon neutrality,this sets to increase significantly with most of the energy sources from renewables.As a result,cost-effective and resource efficient energy conversion and storage will have a great role to play in energy decarbonization.This review focuses on the most recent developments of one of the most promising energy conversion and storage technologies-the calcium-looping.It includes the basics and barriers of calcium-looping beyond CO_(2) capture and storage(CCS)and technological solutions to address the associated challenges from material to system.Specifically,this paper discusses the flexibility of calcium-looping in the context of CO_(2) capture,combined with the use of H_(2)-rich fuel gas conversion and thermochemical heat storage.To take advantage of calcium-looping based energy integrated utilization of CCS(EIUCCS)in carbon neutral power generation,multiple-scale process innovations will be required,starting from the material level and extending to the system level.

The status and development proposal of carbon sources and sinks monitoring satellite system

In order to mitigate global warming,the international communities actively explore low-carbon and green development methods.According to the Paris Agreement that came into effect in 2016,there will be a global stocktaking plan to carry out every 5 years from 2023 onwards.In September 2020,China proposed a"double carbon"target of carbon peaking before 2030 and carbon neutrality before 2060.Achieving carbon peaking and carbon neutrality goals requires accurate carbon emissions and carbon absorptions.China’s existing carbon monitoring methods have insufficient detection accuracy,low spatial resolution,and narrow swath,which are difficult to meet the monitoring requirement of carbon sources and sinks monitoring.In order to meet the needs of carbon stocktaking and support the monitoring and supervision of carbon sources and sinks,it is recommended to make full use of the foundation of the existing satellites,improve the detection technical specifications of carbon sources and sinks monitoring measures,and build a multi-means and comprehensive,LEO-GEO orbit carbon monitoring satellite system to achieve higher precision,higher resolution and multi-dimensional carbon monitoring.On this basis,it is recommended to strengthen international cooperation,improve data sharing policy,actively participate in the development of carbon retrieval algorithm and the setting of international carbon monitoring standards,establish an independent and controllable global carbon monitoring and evaluation system,and contribute China’s strength to the global realization of carbon peaking and carbon neutrality.

China’s energy transitions for carbon neutrality:challenges and opportunities

The pledge of achieving carbon peak before 2030 and carbon neutrality before 2060 is a strategic decision that responds to the inherent needs of China’s sustainable and high-quality development,and is an important driving force for promoting China’s ecological civilization constructions.As the consumption of fossil fuel energy is responsible for more than 90%of China’s greenhouse gases emissions,policies focusing on energy transition are vital for China accomplishing the goal of carbon neutrality.Considering the fact that China’s energy structure is dominated by fossil fuels,especially coal,it is urgent to accelerate the low-carbon transition of the energy system in a relatively short time,and dramatically increase the proportion of clean energy in the future energy supply.Although China has made notable progress in the clean energy transition in the past,its path to carbon neutrality still faces many significant challenges.During the process of energy transformation,advanced technologies and greater investment will play essential parts in this extensive and profound systemic reform for China’s economy and society.In the meantime,these changes will create immense economic opportunities and geopolitical advantages.

Role of CCUS in carbon neutral power system

Achieving carbon neutrality by 2060 is an ambitious goal to promote the green transition of economy and society in China.Highly relying on coal and contributing nearly half of CO_(2) emission,power industry is the key area for reaching carbon-neutral goal.On basis of carbon balance,a criterial equation of carbon neutral for power system is provided.By means of the equation,the different effects of three technical approaches to achieve carbon neutrality,including energy efficiency improvement,shifting energy structure and CO_(2) capture,utilization and storage(CCUS)technology,had been evaluated.The results indicate that building a carbon-neutral power system requires comprehensive coordination between energy efficiency,renewable energy and CCUS technology.In particular,the unique role of CCUS in achieving carbon neutral target was investigated.For any power systems with fossil energy input,CCUS and negative emission technologies is indispensable to reach carbon neutrality.However,rather high energy consumption and costs is the critical gas deterring the large scale deployment of CCUS.Considering the specific conditions of China’s power industry,before the time window between 2030 and 2040 being closed,CCUS would either be ready for large scale deployment by reducing energy consumption and costs,or be phased out along with the most coal power plants.Conclusively,carbon neutral scenario will give CCUS the last chance to decarbonize the fossil fuel,which has great significance for China.

PEM water electrolysis for hydrogen production:fundamentals,advances,and prospects

Hydrogen,as a clean energy carrier,is of great potential to be an alternative fuel in the future.Proton exchange membrane(PEM)water electrolysis is hailed as the most desired technology for high purity hydrogen production and self-consistent with volatility of renewable energies,has ignited much attention in the past decades based on the high current density,greater energy efficiency,small mass-volume characteristic,easy handling and maintenance.To date,substantial efforts have been devoted to the development of advanced electrocatalysts to improve electrolytic efficiency and reduce the cost of PEM electrolyser.In this review,we firstly compare the alkaline water electrolysis(AWE),solid oxide electrolysis(SOE),and PEM water electrolysis and highlight the advantages of PEM water electrolysis.Furthermore,we summarize the recent progress in PEM water electrolysis including hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)electrocatalysts in the acidic electrolyte.We also introduce other PEM cell components(including membrane electrode assembly,current collector,and bipolar plate).Finally,the current challenges and an outlook for the future development of PEM water electrolysis technology for application in future hydrogen production are provided.

A comprehensive review of planning,modeling,optimization,and control of distributed energy systems

Distributed energy system,a decentralized low-carbon energy system arranged at the customer side,is characterized by multi-energy complementarity,multi-energy flow synergy,multi-process coupling,and multi-temporal scales(n-M characteristics).This review provides a systematic and comprehensive summary and presents the current research on distributed energy systems in three dimensions:system planning and evaluation,modeling and optimization,and operation and control.Under the regional environmental,resource,and policy constraints,planning distributed energy systems should fully integrate technical,economic,environmental,and social factors and consider device characteristics,system architecture,and source-load uncertainties.Further,this review presents four modeling perspectives for optimizing and analyzing distributed energy systems,including energy hub,thermodynamics,heat current,and data-driven.The system’s optimal operation and scheduling strategies,disturbance analysis,and related control methods are also discussed from the power system and thermal system,respectively.In all,more research is required for distributed energy systems based on an integrated energy perspective in optimal system structure,hybrid modeling approaches,data-driven system state estimation,cross-system disturbance spread,and multi-subject interaction control.

Correction:Assessment of wind and photovoltaic power potential in China

Following publication of the original article[1],the authors reported some errors in Table 5.The correct Table 5 has been provided in this Correction.The original article[1]has been updated.

Recent progress of quantum dots for energy storage applications

The environmental problems of global warming and fossil fuel depletion are increasingly severe,and the demand for energy conversion and storage is increasing.Ecological issues such as global warming and fossil fuel depletion are increasingly stringent,increasing energy conversion and storage needs.The rapid development of clean energy,such as solar energy,wind energy and hydrogen energy,is expected to be the key to solve the energy problem.Several excellent literature works have highlighted quantum dots in supercapacitors,lithium-sulfur batteries,and photocatalytic hydrogen production.Here,we outline the latest achievements of quantum dots and their composites materials in those energy storage applications.Moreover,we rationally analyze the shortcomings of quantum dots in energy storage and conversion,and predict the future development trend,challenges,and opportunities of quantum dots research.

Beyond cost reduction:improving the value of energy storage in electricity systems

From a macro-energy system perspective,an energy storage is valuable if it contributes to meeting system objectives,including increasing economic value,reliability and sustainability.In most energy systems models,reliability and sustainability are forced by constraints,and if energy demand is exogenous,this leaves cost as the main metric for economic value.Traditional ways to improve storage technologies are to reduce their costs;however,the cheapest energy storage is not always the most valuable in energy systems.Modern techno-economical evaluation methods try to address the cost and value situation but do not judge the competitiveness of multiple technologies simultaneously.This paper introduces the‘market potential method’as a new complementary valuation method guiding innovation of multiple energy storage.The market potential method derives the value of technologies by examining common deployment signals from energy system model outputs in a structured way.We apply and compare this method to cost evaluation approaches in a renewables-based European power system model,covering diverse energy storage technologies.We find that characteristics of high-cost hydrogen storage can be more valuable than low-cost hydrogen storage.Additionally,we show that modifying the freedom of storage sizing and component interactions can make the energy system 10% cheaper and impact the value of technologies.The results suggest looking beyond the pure cost reduction paradigm and focus on developing technologies with suitable value approaches that can lead to cheaper electricity systems in future.

Strategies and reaction systems for solardriven CO_(2) reduction by water

Solar driven CO_(2) conversion into high-value-added chemicals and energy-rich fuels is one of the promising strategies to tackle global warming and to address the energy-supply crisis.Even though enormous effort has been devoted to exploring all sorts of homogeneous and heterogeneous photocatalysts,the current efficiency and more importantly selectivity to valuable chemicals are still rather moderate,thus it is desired to develop high-efficiency photocatalytic system toward CO_(2) reduction with excellent selectivity.In this review,fundamental aspects of photocatalytic CO_(2) reduction by pure water,the reaction systems and the reliable method for detection of the products are firstly described.Thereafter the recent advances of the main strategy for improving the photocatalytic CO_(2) reduction from the perspective of promoting the CO_(2) adsorption and activation,accelerating the kinetics of water oxidation,and modulating charge separation are overviewed.The prospects and challenges on precise designing heterogeneous catalysts for CO_(2) photoreduction are proposed at the end,indicating the significance for the further development of photocatalytic systems with high CO_(2) conversion efficiency and product selectivity.

Analysis on the high‑quality development of nuclear energy under the goal of peaking carbon emissions and achieving carbon neutrality

Striving to peak carbon emissions and achieve carbon neutrality(known as the"Dual-Carbon"goal)is an inevitable requirement for elevating the environmental resource constraints and realizing harmonious coexistence between the mankind and the earth.In the energy system,nuclear energy offers various advantages,such as high energy density,low carbon emission,strong environmental adaptability and large potential for energy co-generation and co-supply.It is one of the supporting energy sources for the transformation and upgradation of the energy system to a clean,efficient and low-carbon way.In this paper,the opportunities and challenges for innovation-driven nuclear energy development in the fields of electricity generation,hydrogen production,heat supply and seawater desalination under the goal of"Dual-Carbon"are discussed and analyzed.Besides,the relevant research on improving the safety and economy of the pressurized water reactor(PWR)and sodium-cooled fast reactor(SFR)conducted by the Nuclear THermal-hydraulic research Lab(NuTHeL)of Xi’an Jiaotong University is briefly introduced.

Climate policy uncertainty and corporate investment:evidence from the Chinese energy industry

In recent years,with the increasing attention paid to climate risks,the changes in climate policies are also more full of uncertainties,which have brought tremendous impact to economic entities,including companies.Using the dynamic threshold model,this study investigates the nonlinear and the asymmetric effect of climate policy uncertainty on Chinese firm investment decisions with panel data of 128 Chinese energy-related companies from 2007 to 2019.The empirical findings indicate that the influence of climate policy uncertainty on firm investment is significantly nonlinear.Overall,climate policy uncertainty is not apparently related to corporate investments in the high-level range,while it negatively affects the investments in the low-level range.In addition,to be more specific,the negative impact of climate policy uncertainty on the mining industry is tremendous,while the influence on the production and supply of electricity,heat,gas,and water sector is remarkably positive.The results of this study could help the company managers and policymakers to arrange appropriate related strategies under different climate policy conditions.

The impact of ESG on financial performance:a revisit with a regression discontinuity approach

This study revisits the question of“whether firms are doing well by doing good?”.We examine shareholders-sponsored corporate socially responsible(CSR)proposals related to Environmental,Social,and Governance(ESG)that are voted to pass or fail by a small margin.The adoption of those“close call”proposals is regarded as equivalent to a random assignment of CSR policies and,therefore,provides a quasi-experimental setting to capture the causal influence of CSR on firm performance.We apply the regression discontinuity design(RDD)and find that CSR proposals’passage leads to a significant positive abnormal return on the voting day.The results are robust with both parametric and nonparametric approaches of RDD and different polynomial orders.However,we fail to identify a significant change in financial performance in the long-term.One possible reason is that passing a CSR proposal could be symbolic,rather than substantial.

Current dilemma in photocatalytic CO_(2) reduction:real solar fuel production or false positive outcomings?

Solar driven carbon dioxide(CO_(2))recycling into hydrocarbon fuels using semiconductor photocatalysts offers an ideal energy conversion pathway to solve both the energy crisis and environmental degradation problems.However,the ubiquitous presence of carbonaceous contaminants in photocatalytic CO_(2) reduction system and the inferior yields of hydrocarbon fuels raise serious concerns about the reliability of the reported experimental results.Here in this perspective,we focus on the accurate assessment of the CO_(2) reduction products,systemically discuss the possible sources of errors in the product quantification,elaborate the common mistakes spread in the analysis of reaction products obtained in 13CO_(2) labelling experiments,and further propose reliable protocols for reporting the results of these isotopic tracing experiments.Moreover,the challenges and cautions in the precise measurement of O_(2) evolution rate are also depicted,and the amplification of the concentration of O_(2) in photoreactors well above the limit of detection is still demonstrated to be the most effective solution to this troublesome issue.We hope the viewpoints raised in this paper will help to assessment the reliability of the reported data in future,and also benefit the beginners that intend to dive in the photocatalytic CO_(2) reduction area.