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Thermodynamic energy conversion efficiencies
Journal of Applied Physics, 1980Much recent work on thermodynamic energy conversion efficiencies is here presented ab initio and from a unified point of view. New considerations are offered and previous work is analyzed in light of the unified presentation. The energy conversion processes discussed include, for example, the conversion into light in a laser or light-emitting diode and
P. T. Landsberg, G. Tonge
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Energy Conversion Efficiency in Nanotube Optoelectronics
Nano Letters, 2005We present theoretical performance estimates for nanotube optoelectronic devices under bias. Current-voltage characteristics of illuminated nanotube p-n junctions are calculated using a self-consistent nonequilibrium Green's function approach. Energy conversion rates reaching tens of percent are predicted for incident photon energies near the band gap ...
Derek Stewart, François Léonard
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Energy Conversion Efficiencies
2012Efficiency is a measure of the true effectiveness or performance of a system or a process. It may take different forms but it can generally be defined as the desired output over the required input. Energy conversion efficiency refers to an efficiency definition for a device for which one form of energy is converted to another form.
Mehmet Kanoglu +2 more
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Wind Energy Conversion Efficiency Limit [PDF]
Wind Engineering, 2006 The momentum analysis of Sharpe [3] is considered further. It is shown that the maximum wind energy conversion efficiency limit, or the Betz limit of 59.3%, deduced from conventional actuator disc theory is the limiting stationary maximum value as wind turbine rotor speed approaches infinity and rotor outlet swirl approaches zero.
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Power Chips for Efficient Energy Conversion
AIP Conference Proceedings, 2004The Power Chips technology employs a gap of 4–10 nanometers in a gap diode to allow for efficient thermal conversion with very low thermal leakage. The design ΔT is on the order of 400 degrees single stage, with operation possible from 1 K to 1600 K, depending on configuration and meeting engineering challenges.
Avto Tavkhelidze, Isaiah W. Cox
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Efficient solar energy conversion with CuInS2
Nature, 1986The high absorptivity associated with a direct energy gap in the optimum range for solar-energy conversion makes CuInS2 a particularly promising material for efficient solar-energy conversion1. Achieved solar-to-electrical conversion efficiencies have been limited to ∼6% (refs 2–8).
H. J. Lewerenz +3 more
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Solar Energy Conversion Efficiency Project
1989Report of a discussion on possible collaborative experimentation to test and refine biomass production models based on the conversion of solar energy by plant stands, and to evaluate alternative models.
João Pereira, J. J. Landsberg
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Energy Conversion in Thermocells: Efficiency Calculations
Journal of The Electrochemical Society, 1990The quantities which enter the definition of thermodynamic efficiency are the work performed and the heat delivered to the system. If these quantities are taken for a cyclic process, one may speak about the total efficiency. The Carnot efficiency gives the theoretical maximum limit for the total efficiency.
Tamio Ikeshoji, Signe Kjelstrup Ratkje
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Energy Conversion Efficiency of Synthetic Jets
ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems, MEMS and NEMS: Volume 1, 2011Synthetic jets are driven by a periodic electrical signal to generate pulsated airflow that can provide cooling to a hot surface. The working principle of synthetic jets involves conversion of electrical energy into mechanical and fluid energy. Piezoelectric actuators, comprising of a thin metal substrate bonded to a piezoelectric disk are induced to ...
Ri Li, Mehmet Arik, Rajdeep Sharma
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Efficiency-coefficients in energy conversions with cogeneration
Energy, 1982Abstract Energy-conversion processes with cogeneration, such as the simultaneous production of electricity and heat from coal, are considered. General feasibility conditions, which originate in the laws of thermodynamics and in economic conditions, are given. The question how such processes can be characterized by efficiency coefficients is discussed
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