Current Issue : October - December Volume : 2018 Issue Number : 4 Articles : 5 Articles
For the virtual power plants containing energy storage power stations and photovoltaic and wind power, the output of PV and\nwind power is uncertain and virtual power plants must consider this uncertainty when they participate in the auction in the\nelectricity market. In this context, this paper studies the bidding strategy of the virtual power plant with photovoltaic and wind\npower.Assuming that the upper and lower limits of the combined output of photovoltaic and wind power are stochastically variable,\nthefluctuation rangeof theday-ahead energymarket and capacity price is stochastically variable. If the capacityof the storage station\nis large enough to stabilize the fluctuation of the output of the wind and photovoltaic power, virtual power plants can participate\nin the electricity market bidding. This paper constructs a robust optimization model of virtual power plant bidding strategy in the\nelectricity market, which considers the cost of charge and discharge of energy storage power station and transmission congestion.\nThe model proposed in this paper is solved by CPLEX; the example results show that the model is reasonable and the method is\nvalid....
In this study we analyzed the generation and the potential of the electricity\ncapacity of energy mix in East Africa from 2020 to 2040 including CO2 emission.\nThe predicted results show that the electricity generated from hydro will\ndominate compared to gas, oil, coal, Solar PV, bio-energy and other renewable\nenergy. Some forms of energies such as bio-energy, solar PV will contribute\nless, while the contribution of nuclear will remain insignificant. The oil\nwill continue to emit a lot carbon dioxides compared to the emission from gas\nand coal. The emission of CO2 from total final consumption (TFC) of oil will\nbe high compared to its emission from power generation (PG) of oil. More\nimportantly, the results show a linear relationship between the energy outlook\nand time. This approach of modeling the energy in a linear form simplifies\nsignificantly the analysis of the electricity generation and capacity. Due to this\nhigh emission of CO2, a new policy and a transition from conventional to renewable\nshould be implemented with clean and energy efficiency technology....
Optimal utilization of renewable energy resources needs energy storage capability in integration with the electric grid. Ocean\ncompressed air energy storage (OCAES) can provide promising large-scale energy storage. In OCAES, energy is stored in the form\nof compressed air under the ocean. Underwater energy storage results in a constant-pressure storage system which has potential\nto show high efficiency compared to constant-volume energy storage. Various OCAES concepts, namely, diabatic, adiabatic, and\nisothermal OCAES, are possible based on the handling of heat in the system. These OCAES concepts are assessed using energy and\nexergy analysis in this paper. Roundtrip efficiency of liquid piston based OCAES is also investigated using an experimental liquid\npiston compressor. Further, the potential of improved efficiency of liquid piston based OCAES with use of various heat transfer\nenhancement techniques is investigated. Results show that adiabatic OCAES shows improved efficiency over diabatic OCAES by\nstoring thermal exergy in thermal energy storage and isothermal OCAES shows significantly higher efficiency over adiabatic and\ndiabatic OCAES. Liquid piston based OCAES is estimated to show roundtrip efficiency of about 45% and use of heat transfer\nenhancement in liquid piston has potential to improve roundtrip efficiency of liquid piston based OCAES up to 62%....
The paper starts from the remarkable classical equation of the great nineteenth\ncentury Russian physicist Nikolay Umov E kmc2 where 1 2 k 1,\nm is the mass, c is the speed of light and E is the equivalent energy of m. After\na short but deep discussion of the derivation of Umov we move to Einsteinâ��s\nformula E mc2 where �³ is the Lorentz factor of special relativity and\npoint out the interesting difference and similarity between Umovâ��s k and Lorentz-\nEinstein �³. This is particularly considered in depth for the special case\nwhich leads to the famous equation E mc2 that is interpreted here to be\nthe maximal cosmic energy density possible. Subsequently we discuss the dissection\nof E mc2 into two components, namely the cosmic dark energy density\nE D 21 22mc2 and the ordinary energy density E O mc2 22\nwhere E D E O mc2 . Finally we move from this to the three-part dissection\nwhere we show that E is simply the sum of pure dark energy E(PD)\nplus dark matter energy E(DM) as well as ordinary energy E(O)....
With the rapid and large-scale development of renewable energy, the lack of\nnew energy power transportation or consumption, and the shortage of grid\npeak-shifting ability have become increasingly serious. Aiming to the severe\nwind power curtailment issue, the characteristics of interactive load are studied\nupon the traditional day-ahead dispatch model to mitigate the influence\nof wind power fluctuation. A multi-objective optimal dispatch model with the\nminimum operating cost and power losses is built. Optimal power flow distribution\nis available when both generation and demand side participate in the\nresource allocation. The quantum particle swarm optimization (QPSO) algorithm\nis applied to convert multi-objective optimization problem into single\nobjective optimization problem. The simulation results of IEEE 30-bus system\nverify that the proposed method can effectively reduce the operating cost and\ngrid loss simultaneously enhancing the consumption of wind power....
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