Did you know that 2/3 of all energy we use ends up as waste heat because of how inefficient our energy system is?
Yet we pay for 100% of the energy inputs.
Here’s the US as an example.
Yet we pay for 100% of the energy inputs.
Here’s the US as an example.
Comments
https://flowcharts.llnl.gov/sites/flowcharts/files/styles/orig/public/2024-12/energy-2023-united-states.png?itok=sotMhUGq
That is why I am a big proponent of heat pumps. Even if the electricity comes from burning gas, it is far more efficient than burning gas or oil in a furnace.
It may be wasteful, but the engineering calculation doesn't care if humans exist let alone being present.
The goal of the device is to produce light and minimise heat loss, that is all.
If a person leaves a light on, that's wasteful and careless.
Importing green hydrogen from Africa to Germany to manufacture 2 ton cars for carrying payloads of ~100kg seems silly.
https://bsky.app/profile/henrihorn.bsky.social/post/3ll66syv5tk2b
The exergy of the food needed to ride a bike, is much less than the fuel needed to drive the SUV.
Diffuse sunlight falling on a PV panel to run an e-bike, uses less exergy still. Sunlight is less Exergetic than food or fuel.
Flywheels, pressure chambers, kinetic cranes, stuff like that? It'd be a huge upfront investment, but the ROI on 60% extra energy storage seems... Well, that's economics, not engineering.
Also, nuclear typically 30% efficiency, geothermal 10%.
But "wasting" heat from fission or hot rocks or even coal might be cheaper than wasting oil or gas, that's why it's tolerated.
Not a lot, but it all adds up.
If it's 6%, that's 6% lost of the power output of the generator.
Also losses at the end user before useful work is done by a motor etc.
For thermal power it depends on the temperature. EG
- gas turbine at 1600degC - Carnot limit is 85% efficiency
- geothermal at 160degC - Carnot limit is 30% efficiency
Eg a gas turbine powering a heat pump to heat a room by a small amount, could be 5,000% efficient.