China’s Electricity Market Reform and Power Plants Efficiency

In the past three decades, Chinese electricity industry has experienced a series of regulatory reforms serving different purposes at different stages. In 2002, the former vertically integrated electricity utility - the State Power Corporation (SPC) – was divested and the generation sector was separated from the transmission and distribution networks in an effort to improve production efficiency. In this paper we study the impact of the reform on efficiency of fossil-fired power plants using plant-level data during 2000-2008. Our results from the data envelopment analysis (DEA) and panel regressions show that: 1) the total factor productivity (TFP) growth mainly comes from technological change; 2) the technical efficiency of previously SPC-managed power plants is converging to that of better-performing independent power producers (IPPs); 3) capacity utilization and unit size are significant factors affecting changes in technical efficiency and the pattern of converging technical efficiency between the two kinds of power plants; 4) most plants operate at increasing returns to scale indicating further cost savings could be achieved through increasing output.Efficiency, DEA, Malmquist Index, China, Electricity, Industrial Organization, Productivity Analysis, Resource /Energy Economics and Policy, D24, L11, L51, L94, L98,

Experimental investigation on performance of fabrics for indirect evaporative cooling applications

© 2016 Indirect evaporative cooling, by using water evaporation to absorb heat to lower the air temperature without adding moisture, is an extremely low energy and environmentally friendly cooling principle. The properties of the wet channel surface in an indirect evaporating cooler, i.e. its moisture wicking ability, diffusivity and evaporation ability, can greatly affect cooling efficiency and performance. Irregular fibres help to divert moisture and enlarge the wetted area, thus promoting evaporation. A range of fabrics (textiles) weaved from various fibres were experimentally tested and compared to Kraft paper, which has been conventionally used as a wet surface medium in evaporative coolers. It was found that most of the textile fabrics have superior properties in moisture wicking ability, diffusivity and evaporation ability. Compared with Kraft paper, the wicking ability of some fabrics was found to be 171%–182% higher, the diffusion ability 298%–396% higher and evaporation ability 77%–93% higher. A general assessment concerning both the moisture transfer and mechanical properties found that two of the fabrics were most suitable for indirective evaporative cooling applications

Experimental investigation of the energy performance of a novel Micro-encapsulated Phase Change Material (MPCM) slurry based PV/T system

© 2015 Elsevier Ltd. As a follow-on work of the authors' theoretical study, the paper presented an experimental investigation into the energy performance of a novel PV/T thermal and power system employing the Micro-encapsulated Phase Change Material (MPCM) slurry as the working fluid. A prototype PV/T module of 800mm×1600mm×50mm was designed and constructed based on the previous modelling recommendation. The performance of the PV/T module and associated thermal and power system were tested under various solar radiations, slurry Reynolds numbers and MPCM concentrations. It was found that (1) increasing solar radiation led to the increased PV/T module temperature, decreased solar thermal and electrical efficiencies and reduced slurry pressure drop; (2) increasing the slurry Reynolds number led to the increased solar thermal and electrical efficiencies, decreased module temperature, and increased pressure drop; and (3) increasing the MPCM concentration led to the reduced module temperature and increased pressure drop. The experimental results were used to examine the accuracy of the established computer model, giving a derivation scale ranging from 1.1% to 6.1% which is an acceptable error level for general engineering simulation. The recommended operational conditions of the PV/T system were (1) MPCM slurry weight concentration of 10%, (2) slurry Reynolds number of 3000, and (3) solar radiation of 500-700W/m 2 ; at which the system could achieve the net overall solar efficiencies of 80.8-83.9%. To summarise, the MPCM slurry based PV/T thermal and power system is superior to conventional air-sourced heat pump systems (ASHP) and solar assisted heat pump systems (ISAHP), and has the potential to help reduce fossil fuel consumption and carbon emission to the environment

Micro-encapsulated phase change material (MPCM) slurries: characterization and building applications

© 2017 Micro-encapsulated Phase Change Material (MPCM) slurries, acting as the heat transfer fluids or thermal storage mediums, have gained applications in various building thermal energy systems, significantly enhancing their energy efficiency and operational performance. This paper presents a review of research on MPCM slurries and their building applications. The research collects information on the currently available MPCM particles and shells, studies of the physical, structural and thermal stability, and rheological properties of MPCM slurries, and identification/determination of the critical parameters and dimensionless numbers relating to the MPCM slurries’ heat transfer. The research suggests possible approaches for enhancing the heat transfer between a MPCM slurry and its surroundings, while several controversial phenomena and potential causes were also investigated. Furthermore, the research presents mathematical correlations established between different thermal and physical parameters relating to the MPCM slurries, and introduces a number of practical applications of the MPCM slurries in building thermal energy systems. Based on such extensive review and analyses, the research will help in identifying the current status, potential problems in existence, and future directions in research, development and practical application of MPCM slurries. It will also promote the development and application of cost-effective and energy-efficient PCM materials and thus contribute to achieving the UK and international targets in energy saving and carbon emission reductions in the building sector and beyond