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When talking about the efficiency of heat engines and power stations the convention should be stated, i.e., HHV (a.k.a. Gross Heating Value, etc.) or LCV (a.k.a. Net Heating value), and whether gross output (at the generator terminals) or net output (at the power station fence) are being considered. The two are separate but both must be stated.
A diesel cycle engine can be as much as 40% to 50% efficient at converting fuel into work, [2] where a typical automotive gasoline engine's efficiency is about 25% to 30%. [ 3 ] [ 4 ] In general, an engine is designed to run on a single fuel source and substituting one fuel for another may affect the thermal efficiency.
To express the efficiency of a generator or power plant as a percentage, invert the value if dimensionless notation or same unit are used. For example: A heat rate value of 5 gives an efficiency factor of 20%. A heat rate value of 2 kWh/kWh gives an efficiency factor of 50%. A heat rate value of 4 MJ/MJ gives an efficiency factor of 25%.
AMFA specifies the energy content of 100 cubic feet of natural gas to be equal to 0.823 gallons-equivalent of natural gas, and the gallon equivalency of natural gas is considered to have a fuel content, similar to that for alcohol fuels, equal to 0.15 gallons of fuel.
But for an instantaneous fuel consumption rate, the thermal efficiency may be better. The theoretical limit for a conventional furnace's instantaneous efficiency is 100%, whereas a heat pump used for building heating may exceed 100%. For example, a COP of 1.5 is equivalent to 150%. Heat pumps are readily available for electric and gas sources. [3]
In a simple cycle gas-turbine, also known as open-cycle gas-turbine (OCGT) generators, hot gas drives a gas turbine to generate electricity. This type of plant is relatively cheap to build and can start very quickly, but due to its lower efficiency is at most only run for a few hours a day as a peaking power plant. [8]
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A 1 inch tall uranium fuel pellet is equivalent to about 1 ton of coal, 120 gallons of crude oil, or 17,000 cubic feet of natural gas. [15] In light-water reactors , 1 kg of natural uranium – following a corresponding enrichment and used for power generation– is equivalent to the energy content of nearly 10,000 kg of mineral oil or 14,000 ...