Review of transition paths for coal-fired power plants

The energy sector has an essential role in limiting the global average temperature increase to below 2°C.Redirecting and advancing technological progress contribute to carbon-free transition solutions.Energy transition is currently one of the most debated issues in the world.This paper reviews and summarizes the current policy projections and their assumptions organized by some major countries in the energy sector,particularly in the coal sector,and provides a detailed discussion on specific and significant socio-technical pathways taken by countries to achieve zero-carbon targets.Their implementation involves restructuring the existing energy system and requires appropriate policy support and sufficient investment in infrastructure development and technological innovation.Some basic principles and countermeasures that have already been implemented by some major emitters,such as India and China,are also discussed,with different transformation pathways.Critical suggestions are also provided,such as implementing best practice policies at the national level,moving to more efficient transition strategies,national and regional cooperation,cross-border energy grid integration,and private sector involvement to reduce carbon emissions from coal-fired power plants,not only by reducing coal consumption but also by introducing various low carbon technologies.

Conductor selection and economic analysis of D.R.congo–guinea±800 kV UHVDC transmission project

Africa is embracing new opportunities featured with industrialization,urbanization and regionalization.Based on co-development of‘Electricity,Mining,Metallurgy,Industry and Trade’and grids interconnection proposed by Global Energy Interconnection Development and Cooperation Organization(GEIDCO),the high-quality hydropower resource of the Congo River can be exploited in large scale under the wide-range interconnected framework of African Energy Interconnection(AEI),forging a new engine for Africa economy.The transmission distance of the Congo River hydropower reaches 6,000 km at its farthest end in North Africa,which brings forth challenges to economics of proposed projects.Under this novel continental energy interconnection scheme in Africa,economics of those projects have not yet been in detail studied.This paper has implemented China’s mature engineering experiences and analytical tools of UHVDC project planning into the AEI structure,through exploring the economic behavior of ultra-long distance UHVDC projects in the scope of conductor selection in the Congo River hydropower transmission for the first time,and has provided concerned parties with a technical and analytical results of their economics comparison.This paper has chosen the D.R.Congo-Guinea±800 kV UHVDC project as a typical example.Its preliminary system planning is introduced and three types of conductor are selected for scheme comparison.Later in this paper,the transmission loss,total investment and equivalent annual cost of the project have been calculated and analyzed.In the final part,sensitivity analysis results of the annual cost to utilization hours,transmission loss,loss tariff and construction cost has been provided.

Preliminary study on the exploitation plan of the mega hydropower base in the lower reaches of Congo River

There have been few studies on the hydropower exploitation plan for sections beyond the Inga hydropower project(HPP)in the lower reaches of the Congo River.Based on topographic and hydrological data of the basin,the exploitation plan for the lower reaches of the Congo River is herein studied.The preliminary proposal involves exploitation using three-cascade hydropower stations.The Grand Inga HPP is the core of the mega hydropower base.The full supply level(FSL)of the reservoir,installed capacity,and regulation performance of the Grand Inga HPP are studied in detail.The main advantages and disadvantages of the high and low dam schemes of the Grand Inga Hydropower Project are compared,in addition to their effects on the overall development of the hydropower base.Moreover,the installed capacity is optimized based on the load characteristics.Based on simulation of cascade hydropower operation and comprehensive analysis,the project scale and implementation sequence is proposed.The influence of hydropower on socio-economic development,energy supply,and emission reduction is analyzed.Finally,the optimal exploitation scheme of the mega hydropower base for the lower reaches of the Congo River is proposed.

Matching theory based user-grouping for indoor non-orthogonal multiple access visible light communication heterogeneous networks

This Letter proposes a model of indoor visible light communication(VLC)heterogeneous networks entirely based on LEDs with different specifications and applies non-orthogonal multiple access(NOMA)to it because of the narrow modulation bandwidth of LEDs.Moreover,a user-grouping scheme that is based on matching theory is proposed to improve the network achievable sum rate.Simulation results indicate that when each NOMA cluster contains 6 users,the proposed scheme has a 49.54%sum-rate enhancement compared with the traditional user-grouping scheme.As the number of users in each NOMA cluster increases,the proposed scheme performs better at the cost of computational complexity.