That's not quite what this is about. It is the Primary Energy Fallacy, that if you are to replace eg coal, you need to replicate its original energy content.
If 1kg of coal represents 1000 Wh, your generator loses 1/2 to waste heat, you only generate 500 Wh of usable electricity. Some analyses will state that renewable power has to replace the 1000 Wh of embedded energy within the coal, when it only needs to output 500 Wh.
If you use solar panels and generate 500 Wh directly, you have cut your energy use in half, even though the output has remained the same. An EV has a battery of ~80 kWh, equal to 2-3 gallons of gas, yet it can go a few hundred miles, a 3-4x ratio of efficiency, compared to an ICE.
Electric motors have gotten ridiculously efficient. In the right power curve you can hit 95%, which is why we have now moved onto power per unit weight and unit volume. You make the drivetrain lighter you reduce the power needed for 0-60 times, which gets you a few more percent of efficiency.
Same thing with battery power density - it’s the rocket equation. Heavy batteries don’t go far. To go farther you add battery, then more battery to carry enough power to carry the larger battery. Increase the specific energy rather than the mass, and all the extra power goes into going faster or farther.
I think your EV example is a better example than your coal one.
I’ve never seen anyone measure coal power by the amount of chemical energy stored inside, unless they are specifically referring to using it as a heating source. For electricity generated by coal it’s always measured as output.
A good visualisation for this I think are linked. Petrol/diesel use about 20% of the available energy and electric vehicles use about 80-90% for moving the vehicle.
> An EV has a battery of ~80 kWh, equal to 2-3 gallons of gas, yet it can go a few hundred miles, a 3-4x ratio of efficiency, compared to an ICE.
Now compare size and weight of the battery with 3 gallons of gas. I can carry hundreds of miles of travel on my person if it's gas, I can't carry much battery though.
Meanwhile, fossil fuels are only 'cheap' because the users are pushing the negative externalities off on everyone else in the world. Priced properly they'd be even more costly than they already are.
World energy production is increasing with solar coming to the forefront.
It is something overlooked by various reports of "In X amount of time, Y is projected to consume Z% of electricity" that the average increase in world electricity production is about 3% per year.
And the average increase in world population is about 1% per year, plus the bulk of the existing population is 'developing' i.e industrialization.
As fast as solar, wind, etc electricity production grows, the number of people requiring it grows along-side.
Also, 'renewable' is misleading, 'replaceable' is more accurate, all renewable energy generators wear out as everything does and need to be replaced using non-renewable energy mostly (you can't build solar panels from solar panel energy)
Why? I didn't start using more energy elsewhere when I switched to an EV or electric lawn maintenance tools. You think companies and people are using exactly as much power as available (or they can afford)?
It's a well-known "paradox" known as Jevons Paradox. Given enough efficient use of a resource, overall usage could actually far outpace the efficiency gains. E.g. use of coal got efficient enough that travel via trains using it became possible, which led to way more usage of coal.
Can confirm Jevons Paradox. But in a more environmentally friendly way.
Just took my house onto off-grid solar, yet my energy consumption now exceeds when I was on utility grid power.
Naturally we ration things when they're expensive. But now I don't feel the need to turn off the lights or appliances when I leave my home, and my EV driving has gone up knowing that "fuel" is essentially free from here on out. And to soak up excess solar, I run multiple computers and servers 24/7 with reckless abandon.
How far does it scale? Because I imagine there must be diminishing returns at some point. And even so, having a lot more renewable energy also means less cancer.
It kinda depends on where the energy is coming from.
I was brought up to "save energy ". Lights switched off when not in thevroom, that sort of thing.
Now I gave solar on the roof. There's an excess production capability, so now, during most days it doesn't matter if stuff is on or off. That especially applies to AC which I'll happily turn on on hot summer days. In effect I use more "because it's there to be used".
My EV is coming soon and given I can charge it on solar I plan to do a lot more day-trips-out over weekends etc.
So you're right, availability and affordability- but electrifying is great (for me) for both those things.
That's not quite what this is about. It is the Primary Energy Fallacy, that if you are to replace eg coal, you need to replicate its original energy content.
If 1kg of coal represents 1000 Wh, your generator loses 1/2 to waste heat, you only generate 500 Wh of usable electricity. Some analyses will state that renewable power has to replace the 1000 Wh of embedded energy within the coal, when it only needs to output 500 Wh.
If you use solar panels and generate 500 Wh directly, you have cut your energy use in half, even though the output has remained the same. An EV has a battery of ~80 kWh, equal to 2-3 gallons of gas, yet it can go a few hundred miles, a 3-4x ratio of efficiency, compared to an ICE.
Electric motors have gotten ridiculously efficient. In the right power curve you can hit 95%, which is why we have now moved onto power per unit weight and unit volume. You make the drivetrain lighter you reduce the power needed for 0-60 times, which gets you a few more percent of efficiency.
Same thing with battery power density - it’s the rocket equation. Heavy batteries don’t go far. To go farther you add battery, then more battery to carry enough power to carry the larger battery. Increase the specific energy rather than the mass, and all the extra power goes into going faster or farther.
I think your EV example is a better example than your coal one.
I’ve never seen anyone measure coal power by the amount of chemical energy stored inside, unless they are specifically referring to using it as a heating source. For electricity generated by coal it’s always measured as output.
The battery loses 10% just by charging it.
I figured an EV is worth about 60mpg with a fair comparison to a gas car.
A good visualisation for this I think are linked. Petrol/diesel use about 20% of the available energy and electric vehicles use about 80-90% for moving the vehicle.
https://yaleclimateconnections.org/2024/01/electric-vehicles...
A litter of petrol is about 34MJ or about 9.5kWh
It propels a car about 10 miles. About 1 mile per kWh
Charging my electric car via AC at 7kW to replace the power used to drive 90 miles in autumn takes 26kWh according to the meter, so 3.5 miles per kWh.
Oil also loses quite a bit during refining and transport.
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> An EV has a battery of ~80 kWh, equal to 2-3 gallons of gas, yet it can go a few hundred miles, a 3-4x ratio of efficiency, compared to an ICE.
Now compare size and weight of the battery with 3 gallons of gas. I can carry hundreds of miles of travel on my person if it's gas, I can't carry much battery though.
> I can carry hundreds of miles of travel on my person if it's gas, I can't carry much battery though.
Particularly handy if heading off in a straight line, I to the wilderness.
Most of us are running errands around town.
That's true, we should clearly be powering our cars with uranium, or perhaps plutonium.
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It doesn't say it would cut energy costs in half.
Meanwhile, fossil fuels are only 'cheap' because the users are pushing the negative externalities off on everyone else in the world. Priced properly they'd be even more costly than they already are.
World energy production is increasing with solar coming to the forefront.
It is something overlooked by various reports of "In X amount of time, Y is projected to consume Z% of electricity" that the average increase in world electricity production is about 3% per year.
And the average increase in world population is about 1% per year, plus the bulk of the existing population is 'developing' i.e industrialization.
As fast as solar, wind, etc electricity production grows, the number of people requiring it grows along-side.
Also, 'renewable' is misleading, 'replaceable' is more accurate, all renewable energy generators wear out as everything does and need to be replaced using non-renewable energy mostly (you can't build solar panels from solar panel energy)
> you can't build solar panels from solar panel energy
... Why?
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Why? I didn't start using more energy elsewhere when I switched to an EV or electric lawn maintenance tools. You think companies and people are using exactly as much power as available (or they can afford)?
It's a well-known "paradox" known as Jevons Paradox. Given enough efficient use of a resource, overall usage could actually far outpace the efficiency gains. E.g. use of coal got efficient enough that travel via trains using it became possible, which led to way more usage of coal.
Can confirm Jevons Paradox. But in a more environmentally friendly way.
Just took my house onto off-grid solar, yet my energy consumption now exceeds when I was on utility grid power.
Naturally we ration things when they're expensive. But now I don't feel the need to turn off the lights or appliances when I leave my home, and my EV driving has gone up knowing that "fuel" is essentially free from here on out. And to soak up excess solar, I run multiple computers and servers 24/7 with reckless abandon.
How far does it scale? Because I imagine there must be diminishing returns at some point. And even so, having a lot more renewable energy also means less cancer.
2 replies →
It kinda depends on where the energy is coming from.
I was brought up to "save energy ". Lights switched off when not in thevroom, that sort of thing.
Now I gave solar on the roof. There's an excess production capability, so now, during most days it doesn't matter if stuff is on or off. That especially applies to AC which I'll happily turn on on hot summer days. In effect I use more "because it's there to be used".
My EV is coming soon and given I can charge it on solar I plan to do a lot more day-trips-out over weekends etc.
So you're right, availability and affordability- but electrifying is great (for me) for both those things.
> Unlikely. We'd just use the leftover energy for new things.
You mean data centers. Can't ever have enough of those!