Efficiency of Advanced Ground Transportation Technologies

2002 ◽  
Vol 124 (3) ◽  
pp. 173-179 ◽  
Author(s):  
Frank Kreith ◽  
Ron E. West ◽  
Beth E. Isler
Keyword(s):  
Natural Gas ◽  
Electric Vehicles ◽  
Hybrid Electric Vehicles ◽  
Fuel Cycle ◽  
Primary Energy ◽  
Motor Vehicles ◽  
Fuel Production ◽  
Different Types ◽  
Transportation Technologies ◽  
Methanol Fuel Cell

This paper presents thermodynamic analyses of ten different scenarios for using natural gas to power motor vehicles. Specifically, it presents a comparison between different types of automotive vehicles using fuels made from natural gas feedstock. In comparing the various fuel-vehicle options, a complete well-to-wheel fuel cycle is considered. This approach starts with the well at which the feedstock is first extracted from the ground and ends with the power finally delivered to the wheels of the vehicle. This all-inclusive comparison is essential in order to accurately and fairly compare the transportation options. This study indicates that at the present time hybrid-electric vehicles, particularly those using diesel components, can achieve the highest efficiency among available technologies using natural gas as the primary energy source. Hydrogen spark ignition, all-electric battery-powered, and methanol fuel cell vehicles rank lowest in well-to-wheel efficiency because of their poor fuel production efficiencies.

scholarly journals Fuelwood Comparison with Other Kinds of Fuel

2006 ◽  
Vol 1 ◽  
pp. 67
Author(s):  
J. Dolacis ◽  
E. Tomsons ◽  
J. Hrols
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Liquid Fuel ◽  
Calorific Value ◽  
Primary Energy ◽  
Energy Resources ◽  
Fuel Wood ◽  
Total Consumption ◽  
Different Types ◽  
Dry Wood

A part of Latvia’s forest resources, namely, branches, stumps, small stump top ends, firewood, slabs, sawdust, etc. remains unutilised both in the felling sites and woodworking plants. All this can be successfully utilised for production of heat energy, thereby replacing a part of the imported natural gas, coal and liquid fuel. To assess the utilisation of a definite type of primary energy, not only its accessibility and costs, but also calorific value should be known. The rational utilisation of energy resources in Latvia is urgent, since less than 30% from the consumption is obtained in this country. Thus, in 2000, the Latvia’s energy balance showed the total consumption of different types of primary energy resources to be 159 145 TJ (T = 1012). Utilising firewood, woodworking waste and chips, 34 250 TJ of energy was produced, or 21.5 % from the total primary energy consumed in Latvia. In the present study, fuel wood is compared with other types of fuel. If the equivalent value of one ton of coal (tce) is 29.308 MJ/kg, then the calorific value of natural gas and dry wood is 1.507 and 0.644, respectively. If 18.883 MJ of heat is obtained from 1 kg of oven dry wood, then 1.3 kg of wood with the relative moisture (Wr) content 20% and about 2.0 kg of freshly cut wood are necessary. To replace 1 ton of sawdust pellets or granules, 2.44 steres of birch firewood with the moisture content Wr = 20% or 2.63 steres with Wr = 40% are necessary. The above-mentioned amount of pellets or granules can be replaced by 3.47 steres of spruce firewood with Wr = 20% or 3.76 steres with Wr = 40%. The production of 1 kWh of heat from natural gas yields 0.224 kg of carbon dioxide, but in the case of fully combusted wood, from 0.35 to 0.4 kg of carbon dioxide.

scholarly journals A Provisional Model for the Optimal Management of a Charging Station Assisted by Photovoltaic Panels for Plug-In Electric Vehicles

2021 ◽  
Vol 8 ◽  
pp. 105-117
Author(s):  
Rizzo Gianfranco ◽  
Tiano Francesco Antonio ◽  
Marino Matteo
Keyword(s):  
Electric Vehicles ◽  
Hybrid Electric Vehicles ◽  
Co2 Reduction ◽  
Electrical Energy ◽  
Primary Energy ◽  
Optimal Management ◽  
Nonlinear Constrained Optimization ◽  
Electrical Grid ◽  
Charging Station ◽  
Battery Capacity

There is a strongly increasing diffusion of Electric Vehicles (EV) and Plug-in Hybrid Electric Vehicles (PHEV), in order to reduce air pollution in urban environment and to mitigate the global warming issues. Anyway, the achievement of this latter goal strictly depends on the source of primary energy used to generate electrical energy. In the paper, a model for the optimal design and operation of a charging station for EV and PHEV assisted by a PhotoVoltaic (PV) plant is presented. A provisional model for the estimation of the incoming insolation, based on cloudiness prevision, is integrated with a nonlinear constrained optimization algorithm, in order to satisfy the load while minimizing the recourse to electrical grid for battery storage charging. Simulations on different locations and charging loads for various size of PV plant and battery capacity are presented, and the benefits in terms of CO2 reduction discussed.

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