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
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…
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)
@IDIC Most of this energy loss is because of some fundamental laws of thermodynamics. When you use fossil fuels in transportation or power generation, you burn them in an engine or turbine to convert their chemical energy to mechanical energy. From thermodynamics, we can calculate a maximum to how efficiently you can do that, and sadly even in a perfect world, that maximum is usually only in the order of 40% - 60% of input energy used. Large machines are already close to this maximum.
@jaseg fascinating and sad… could the heat that comes off that be stored or converted to power somehow? Any articles or search terms I could read/use.. high-school level reading though 😬
@IDIC Sadly no. Theoretical upper limit to efficiency is η = 1 - t_low / t_high with temperatures expressed in Kelvin. Waste heat often has a too low temperature to be usable to get some work done. @jaseg @Sheril
Paolo Redaelli
in reply to Sheril Kirshenbaum • • •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…
system that performs the conversion of heat or thermal energy to mechanical work
Contributors to Wikimedia projects (Wikimedia Foundation, Inc.)Paolo Redaelli
in reply to Sheril Kirshenbaum • • •The other is recycling the waste heat of industrial processes to heat homes (my city does exactly this)
Lt. Commander Reggie
in reply to Sheril Kirshenbaum • • •jaseg
in reply to Lt. Commander Reggie • • •Lt. Commander Reggie
in reply to jaseg • • •Paolo Redaelli
in reply to Lt. Commander Reggie • • •Sadly no. Theoretical upper limit to efficiency is η = 1 - t_low / t_high with temperatures expressed in Kelvin. Waste heat often has a too low temperature to be usable to get some work done.
@jaseg @Sheril