Using BTUs to compare electrical sources seems to be deceptive. For thermal sources (fossil fuels) at least 1/3 of the energy is in waste heat, it just goes right up the smokestack. Wind and solar don't have that issue.
What interests me is progress towards reducing carbon dioxide emissions, and as regards electricity generation the inroads Solar+Wind are making on consumption of coal and gas.
As you say, at least one-third** of the energy used from fossil-fuel production of electricity is non-productive. So 1 unit of electrical energy produced from Solar+Wind reduces fossil fuel energy use by 1.5 units.
That is why I produce graphs on primary energy consumed rather than electricity produced. Why British Thermal Units ? - because most of the EIA data on primary energy use is in BTU, except for coal (in short tons - but the EIA gives a conversion factor to BTU).
The same applies to EVs replacement of energy from refined crude to power ICEVs, though I presume with a higher multiplier.
_______________________________________
** While for total electricity generation the energy wasted is about 1/3rd, surely that is because there is little or no wasted energy from renewables + nuclear + hydro. I believe energy efficiency of coal electricity generation is at best a bit over 40%, and for gas at best up to 60% .
That 1/3 proportion of waste heat is an underestimate?If you include the energy loss from mining, extraction, processing and transportation (EROI), i.e. the ratio of the amount of usable energy (the exergy) delivered from a particular energy resource to the amount of exergy used to obtain that energy resource,
that 1/3 proportion of waste heat needs increasing even more.Conventional gas and oil, EROI about 18:1.
Shale gas, performs at about 6.5:1 to 7.6:1.
Tar sands oil 2.9:1 to 5.1 Some say if processing to refined product is included 1:1
Corn ethanol, 1.3:1 Bio-diesel is shown to be pretty dumb.
COAL about 30:1 (excluding transportation)
I could not find a table of generally accepted EROI standard measures.
__________________________________________________________________
So my back of envelope calculation says that each unit of electrical energy produced from Solar+Wind reduces by at least 2 units of energy consumed by Coal+Gas