"How Green Was My Tesla"?
- Thread starter Marshal Jim Duncan
- Start date
The slight of hand here (or at least the one I caught) is using petroleum fueled steam generation. Combined cycle natural gas is much more efficient (which is why it is used widely in the US and petroleum over steam is mainly used in places were oil is cheaper than water like the middle east)
Your assumptions are incorrect. Per the EIA:
Kilowatthour generated per unit of fuel used:
And 1 bbl of petroleum = 5,800.64 cubic feet of natural gas. 5,800.64/1,000 = 5.80064.
5.80064 x 99 = 574.2634
Kilowatthour generated per unit of fuel used:
- 1,927 kWh per ton, or 0.96 kWh per pound, of coal
- 99 kWh per Mcf (1,000 cubic feet) of natural gas
- 578 kWh per barrel, or 13.76 kWh per gallon, of petroleum
And 1 bbl of petroleum = 5,800.64 cubic feet of natural gas. 5,800.64/1,000 = 5.80064.
5.80064 x 99 = 574.2634
- Kilowatthour generated per unit of fuel used:
- 1,927 kWh per ton, or 0.96 kWh per pound, of coal
- 99 kWh per Mcf (1,000 cubic feet) of natural gas
- 578 kWh per barrel, or 13.76 kWh per gallon, of petroleum
Power plant heat rates (for steam electric generators in 2014)
Coal = 10,080 Btu/kWh
Natural gas = 10,408 Btu/kWh
Petroleum = 10,156 Btu/kWh
Further data on the efficiency difference between steam cycle and combined cycle. http://www.eia.gov/electricity/annual/html/epa_08_02.html
http://www.eia.gov/electricity/annual/html/epa_08_02.html
It's mostly a big deal because its abundant and very cheap.
Using the 2015 figures from the combined cycle generation from the link you provided, I get 779.7 kWh per Mcf og NG to 606.1 per bbl of petroleum. So, in that case, you're correct that it produces more energy per unit.
I still don't believe it destroys the thesis that electric cars aren't especially more green than internal combustion vehicles.
I still don't believe it destroys the thesis that electric cars aren't especially more green than internal combustion vehicles.
But you just plug them into your outlet...and when they run I don't see any exhaust.
They aren't. Whether you burn fuel to turn a motor in a car or burn fuel to turn a generator, you burn fuel to produce power in some form.
The only way it becomes significantly more green is if the electric power comes from a source that isn't fossil fuel, assuming generating electricity by those forms in enough quanity to replace fossil isn't just as or more environmentally unfriendly than the fossil fuels.
So is coal. Gas is clean burning and leaps and bounds more thermally efficient.
But they didn't switch to it large scale until it became cheaper relative to coal and/or they were forced to by the government making it so onerous to operate coal fired plants. Switching will still occur (if the government allows it) if the price of NG rises enough.
https://btuanalytics.com/coal-to-gas-switching-in-2016/
