Economic potentials of energy storage technologies in electricity markets with renewables

The increasing penetration of renewables in power systems urgently entails the utilization of energy storage technologies.As the development of energy storage technologies depends highly on the profitability in electricity markets,to evaluate the economic potentials for various types of energy storage technologies under the compre-hensive market environment is of great significance.To this end,this study aims at conducting a quantitative analysis on the economic potentials for typical energy storage technologies by establishing a joint clearing model for electric energy and ancillary service(AS)markets considering the operating features of energy storage systems(ESSs).Furthermore,a test system is adopted for numerical analysis that accurately represents for the real-world operation characteristics of power systems in China,with which the market prices,and operation schedules and profitability of ESSs are comparatively studied.The proposed methodology and results could provide benefi-cial references for the modifications on electricity markets and the development of ESSs towards the increasing penetration of renewables in power systems.

Potential Economic Pitfalls Call for Removal of Institutional Drawbacks——An Interview with Mr. FAN Gang (樊纲), Ph.D. of Economics, Doctoral Advisor, Director of National Research Institute of Economics

The continuous rise of consumer price index (CPI) has increased concern over China's macroeconomic situation. Will inflation have a disastrous impact on the Chinese economy? What risks are brewing behind the booming real estate and stock markets? Have bubbles already occurred in the Chinese economy? From his office in Guohong Building, Beijing, Dr. Fan Gang gave his views on these questions in an exclusive interview with China Economist.

Petrogenesis and Economic Potential of the Sangong MaficUltramafic Intrusion in the Eastern Tianshan, Central Asian Orogenic Belt: Constraints from Mineral, Whole-Rock, and PGE Geochemistry

The Sangong Cu-Ni sulfide mineralized mafic-ultramafic intrusion is located on the southern margin of the Bogeda-Harlik belt,eastern Tianshan,China.The intrusion is a well-differentiated complex and is comprised of leucogabbro,gabbro,olivine gabbro,Pl-bearing peridotite,and Pl-bearing pyroxenite.The Pl-bearing pyroxenite hosts both irregularly disseminated sulfide and round droplet sulfide.The intrusive rocks have a wide range of SiO2(42.1 wt.%-50.48 wt.%)and MgO(6.21 wt.%-22.11 wt.%),and are enriched in light rare earth elements(LREE),large-ion lithophile elements(LILE;e.g.,Rb,Ba,Sr,and Pb),and palladium platinum group elements(PPGE)but depleted in high-field-strength elements(HFSE;e.g.,Nb,Ta,and Ti)and iridium PGEs(IPGE).These geochemical characteristics indicate that the Sangong mafic-ultramafic intrusion was derived from high degree of partial melting of depleted mantle and interacted with subduction-related material.The low Pd/Ir(3.21-27.44)but high Ni/Cu(1.64-24.16)ratios,combined with the olivine crystals with low Fo(60.88-78.65)and Ni(54.99 ppm-1688.87 ppm)concentrations suggest that the parental magma of the Sangong intrusion were likely high MgO basaltic in composition that experienced extensive evolution prior emplacement.The Ce/Pb ratios(5.8-13.6)and Nb/U ratios(11.6-30.3)of the intrusive rocks all range between MORB and crustal values,the Nb/Yb and Th/Yb values are close to the lower crust values,together with the low Se/S ratios[(17-100)×10^(-6))]suggest that the magma experienced assimilation not only in mantle source but also in conduit,but the degree of crustal contamination is limited.The Cu/Pd ratios of the rocks range from 3.9×10^(4) to 10.8×10^(4),and the Cu/Zr ratios of Pl-bearing pyroxenite in the Sangong intrusion are>1,combined with the presence of sulfide droplets in the Pl-bearing pyroxenite,indicating the parental magma experienced sulfide saturation and the economical ore bodies may present in the depth of the intrusion.Furthermore,given the discovery of the Baixintan and Yueyawan deposits,we propose the DananhuHarlik belt as an essential prospecting target for Cu-Ni mineralization in North Xinjiang.

Geology of the Structurally Controlled Quartz Vein Gold Mineralization in the Dikko Area, Part of Zungeru—Minna—Birnin Gwari Schist Belt, NW Nigeria

Dikko area, Niger State, North Central Nigeria falls within the Pan-African thermo-tectonic event which occurred in Nigeria as in other parts of West Africa with widespread effect on the mineralization of rejuvenated basement and geosynclinal trough deposits. The Pan-African Belt in Nigeria forms part of the Benin-Nigeria (Dahomeyan) shield which is regarded as the southern prolongation of the circumcratonic Pan-African belt of the West African Craton. Structurally controlled, gold-bearing quartz veins were measured and studied in the area from an extensive geological ground investigation. Field and petrographical studies indicate that the Neoproterozoic rocks constitute gneisses, amphibolite schist, amphibolites and migmatites. The amphibolites are intruded by pegmatites. The associated quartz veins are generally concordant with the main N-S regional structural trend. The lithological and structural studies carried out in these areas have demonstrated the relationship between structures and mineralization and/or lithology. The main characteristics of the gold mineralization in the area appear to indicate hydrothermal mineralization in connection with shear zones. This study allows us to predict that quartz veins in the amphibolite can be mined at a profit and a detailed geochemical and resource valuation needs to be carried out for the Au and associated Galena and Ag mineralization to fully exploit their economic potential.