Energy Density and Carbon ImpactSee also: Energy value of coal
The energy density of coal, i.e. its heating value, is roughly 24 megajoules per kilogram. (approximately 6.7 kilowatt-hours per kg.) For a coal power plant with a 40% efficiency, it takes an estimated 325 kg (720 lb) of coal to power a 100-W lightbulb for one year.
As of 2006, the average efficiency of electricity-generating power stations was 31%; in 2002, coal represented about 23% of total global energy supply, an equivalent of 3.4 billion tonnes of coal, of which 2.8 billion tonnes were used for electricity generation.
The US Energy Information Agency's 1999 report on CO2 emissions for energy generation quotes an emission factor of 0.963 kg CO2/kWh for coal power, compared to 0.881 kg CO2/kWh (oil), or 0.569 kg CO2/kWh (natural gas).
Read more about this topic: Coal
Famous quotes containing the words impact and/or energy:
“As in political revolutions, so in paradigm choicethere is no standard higher than the assent of the relevant community. To discover how scientific revolutions are effected, we shall therefore have to examine not only the impact of nature and of logic, but also the techniques of persuasive argumentation effective within the quite special groups that constitute the community of scientists.”
—Thomas S. Kuhn (b. 1922)
“The tendencies of the times favor the idea of self-government, and leave the individual, for all code, to the rewards and penalties of his own constitution, which work with more energy than we believe, whilst we depend on artificial restraints.”
—Ralph Waldo Emerson (18031882)