Some research I did back in 2009 follows. Progress is slow. As to efficiency in converting input energy into output electrical energy, there is little if any cost or adverse impact in input/output ratio when wind and solar PV are considered in large part because there are no emissions or waste heat. Similarly, virtually no energy needs to be expended to obtain the wind and solar energy once the plant is in place, while with coal there is a very large energy expenditure just to get the coal to the generating plant.
From July 2009:
http://www.eia.doe.gov/cneaf/electricity/page/co2_report/co2report.html
In the United States, about 40.5 percent(6) of anthropogenic CO2 emissions was attributed to the combustion of fossil fuels for the generation of electricity in 1998, the latest year for which all data are available.(7)
Coal has the highest carbon intensity among fossil fuels, resulting in coal-fired plants having the highest output rate of CO2 per kilowatthour.
CO2 emissions from coal-fired electricity generation comprise nearly 80 percent of the total CO2 emissions produced by the generation of electricity in the United States, while the share of electricity generation from coal was 51.0 percent in 1999 (Table 3).
http://en.wikipedia.org/wiki/Fossil_fuel_power_plant
Subcritical fossil fuel power plants can achieve 36–38% efficiency. Supercritical designs have efficiencies in the low to mid 40% range, with new "ultra critical" designs using pressures of 4,400 psia (30 MPa) and dual stage reheat reaching about 48% efficiency.
Older nuclear power plants must operate below the temperatures and pressures that coal fired plants do. This limits their thermodynamic efficiency to the order of 34–37%. Advanced designs, such as the Advanced gas-cooled reactor and the Supercritical water reactor, operate at temperatures and pressures similar to current coal plants, producing comparable efficiency.
http://www.newton.dep.anl.gov/askasci/eng99/eng99187.htm
. . . this ideal maximum [thermodynamic] conversion efficiency is never achieved, so a
generous estimate would be 50%. In addition, the "true" cost is a much more
complicated calculation. The "true" cost takes into account the cost of
mining and transporting the coal, and the operating costs of the generation
(plant cost, salaries, environmental costs, and so on). The bottom line is
that the conversion of coal into electricity is very inefficient.
Estimate of 30% efficiency of 30% for transforming the heat energy of the coal
into electrical energy and transmitting it to your home – [does not include the energy used in mining, transporting, and handling the coal before it is burned]
http://www.fossil.energy.gov/programs/powersystems/gasification/index.html
DOE estimates: only a third of the energy value of coal is actually converted into electricity, the rest is lost as waste heat.
http://www.energetics.com/gridworks/grid.html
DOE: America operates a fleet of about 10,000 power plants. The average thermal efficiency is around 33%. Efficiency has not changed much since 1960 because of slow turnover of the capital stock and the inherent inefficiency of central power generation that cannot recycle heat.
http://wattwatt.com/pulses/95/i-challenge-you-on-electricity-transmission-have-we-got-it-right/
the overall losses between the power plant and users can easily be between 8 % and 15 %,
http://www.groupsrv.com/science/about326877.html
In any country, the network, through losses, is the biggest consumer of electricity. In Europe, these losses amount to 4-10% of electricity generated, with an average of 7%.
