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Globally we produce A LOT of #energy, but did you know the majority of fossil energy gets wasted? In the US alone, two-thirds of that energy is *wasted* as heat.

As Hannah Ritchie has pointed out, we don’t actually need to produce a low carbon equivalent of all of the coal, oil & gas we currently use.

That means we can decarbonize quickly by being less wasteful & more efficient. #ClimateChange #science

in reply to Sheril Kirshenbaum

Yes, ~60-70%-ish losses are normal in thermal generation processes due to the limits of the Carnot cycle. In cars (small machines, most of the time way off their max efficiency ranges) this goes way beyond 80%.
That's how EVs work even with the limitations of battery tech.

I am just wondering about the word "rejected". This sounds like energy, the grid is not capable of absorbing, like it is deliberately dumped. But, yeah, looking at the graph in total, it's just waste heat (they might as well have called it that).

in reply to Sheril Kirshenbaum

The same for France, made by #Negawattassociation
https://tunebook.fr/systener_collapso.html#2
Note : new release available on :
https://negawatt.org/Scenario-negaWatt-2022
in reply to Sheril Kirshenbaum

intensity targets have been a distraction tactic for decades. We need to leave the fuel in the ground.
in reply to Sheril Kirshenbaum

In this sense, burning HC means a highly exothermic reaction, so performance could be optimized using expansion of gases and steam, water... it would be something like a combined engine...
in reply to Sheril Kirshenbaum

science lover but uneducated — how do we capture that heat, store it/convert to useable energy?
in reply to Sheril Kirshenbaum

Hi Sheril, while it is true that over 2/3 (and sometimes over 3/4) of fuel energy is released as heat, this is an inescapable byproduct of thermodynamics.

A Carnot heat engine has a maximum efficiency of 1 only when the cold reservoir is at absolute zero (0K). We all know the feasibility of achieving that. The cold reservoir is frequently the ambient air temperature, which can be around 300K.
https://en.m.wikipedia.org/wiki/Carnot%27s_theorem_(thermodynamics)

in reply to Sheril Kirshenbaum

so transportation is both the largest use and largest waster of energy, hence the need to switch from fossil fuels to electric?
in reply to Sheril Kirshenbaum

wait. that picture shows all the different energy sources shoved into th orange box and then a percentage from that box to waste heat. BUT doesn't each energy source--> electricity have it's own heat loss %?
in reply to Sheril Kirshenbaum

I think about this a lot. Even noisy cars and machines are wasting energy to make that noise (which eventually ends up as heat too).
in reply to Sheril Kirshenbaum

That's related to the theoretical limit to efficiency of thermal cycles, as Carnot discovered: Heat engine - https://en.wikipedia.org/wiki/Heat_engine#Efficiency
Producing steel and cement require quite a lot of thermal energy. Ditto for aluminum recycling (refining instead is a game where electricity shines 😁).
Combined cycles achieve 50-60% efficiency Combined cycle power plant - https://en.wikipedia.org/wiki/Combined_cycle_power_plant
Please acknowledge that power grid transmission dissipate A LOT of power ~⅓-½ of the input…
in reply to Sheril Kirshenbaum

The only quota that can be actually be cut by cutting CO2 emission is the 21.2% of thermal waste in transportation.
The other is recycling the waste heat of industrial processes to heat homes (my city does exactly this)
in reply to Sheril Kirshenbaum

All use of carbon fuels is deadly waste. A filtghy history ending waste.

24 Billion trees. Twenty Four Billion Trees. With a "B"

Greenland will NO LONGER allow any search, drilling exploration for oil. Ever. Done.

India interrupted their new Five Year Plan to DROP ALL NEW COAL Spending, already budgeted.

The money will be spent on renewables.

Build ALL the new energy needed to END ALL CARBON FUELS FOREVER.

UN-used UN-needed UNderground.

Carbon fuels are death.

#Climate

in reply to Sheril Kirshenbaum

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