That chart is measuring joules of energy. I'm not sure efficiency comes into play here, does it?
Coal provides 175,000,000 TJ of energy. Solar and wind provide 21,000,000 TJ.
I was mostly surprised at how critical coal still is.
That chart is measuring joules of energy. I'm not sure efficiency comes into play here, does it?
Coal provides 175,000,000 TJ of energy. Solar and wind provide 21,000,000 TJ.
I was mostly surprised at how critical coal still is.
The problem is where it's measuring joules of energy. To use cars as an example:
It measures joules of energy as in "how much heat the gasoline we burn produces", some of which we convert to mechanical energy to drive the car, but the majority is just waste heat going out the tailpipe.
By comparison an electric car powered by solar has no tailpipe. There's still a bit of waste heat from electrical resistance, but nowhere near as much.
If we measure like this, by converting a gasoline car to electric (powered by solar for the sake of ignoring some complexity), and driving the same distance, we somehow managed to cut our "energy demand" in half. Despite the fact that we're demanding the exact same thing from the system.
If we measured "joules delivered to the tires of the car" we wouldn't have the same issue. At least until someone starts arguing about how their car is more aerodynamic so joules delivered to the tires should count for more in it.
Edit: We could also go in the other direction. Instead of reporting it as 1kw of solar energy (electricity) it could be 4kw of solar energy (the amount of sunlight shining on the solar panels)... No one does this for obvious reasons, but it's more similar to that primary energy number for fuel in many ways.
> but the majority is just waste heat going out the tailpipe.
It's my understanding that waste heat in a car is about 50/50 the tailpipe and the radiator.
The total energy supply figure is a primary energy mix - for the fossil fuels it represents the thermal energy of the fuel. You can look at the final energy consumption section a bit lower to get a different picture taking into account conversion losses.
That is still subject to the primary energy fallacy. Those reports are in terms of primary energy, i.e. how much heat is released by combustion of fossil gas. But in order to replace fossil gas in a chemical plant, you need much less electricity than the primary energy of the fossil gas suggests.
The IEA says[1]:
> For all energy sources, the IEA clearly defines energy production at the point where the energy source becomes a “marketable product” (and not before).
Doesn't that mean if you are burning coal to make electricity, you wouldn't count the heat output because the generated heat is not a marketable product.
[1] https://www.iea.org/commentaries/understanding-and-using-the...
I interpret "marketable product" to mean gas at the wellhead, coal at the mine terminal.
I didn't interpret it that way because of this line from that page:
> [Total Final Consumption] shows the energy that is actually used by final consumers – the energy used in homes, transportation and businesses.
I'm not buying coal at the terminal to power my television.
Indeed, but were we not looking at TPES before?
Yes we were.
Looking at the chart for TFC, the wind and solar case looks even worse. Wind and solar supplies 2 million TJ compared to 36 million for coal.
All I was really trying to say from the outset is that I'm surprised at how important coal still is and how little we use renewables. I see articles here all the time about the massive advancements in solar (and wind to a lesser degree) and I had it in my head that renewables were a much larger part of the energy mix than they are.
There is lag created by sunk capital costs. Coal is still producing considerable electric power in the US, but the last time a new coal-fired power plant came online was more than a decade ago, and there are none under construction (although Trump was trying to get one built, to considerable skepticism and inertia). The average age of a coal-fired power plant in the US is 40+ years.