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Primary energy vs final energy: why replacing fossil fuels may not be so hard

bloomberg.com

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Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#41

Post by kortilla »

ip26 wrote: post #34
aardvarkr wrote: post #31

Is no one pointing out that this isn’t the part that makes replacing fossil fuels hard? This is focusing on a completely irrelevant metric. It’s a great motivator for why we need to shift but it has no impact on how hard it will be to replace oil. There’s 100 practical reason for why it’s hard, namely that clean energy sources are not under our direct control to scale up and down as we need more/less. We can’t tell t…

FWIW long distance transmission lines work too. Solar peaks a few hours earlier than demand. So ship that power east two timezones.

And which solar panels power California?

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#42

Post by ardit33 »

mcwone wrote: post #25

I found this article interesting: https://media4.manhattan-institute.org/sites/default/files/R...

The guy that wrote is is a big Oil lobyist, and the Manhattan Institue is a conservative/big oil think tank

It is like someone from the early 1900s saying: Combustion engines will never take over, steam is 98% of power... etc.. etc..

yet in 10 years they did take over, first cars, then larger vessels (trains and boats). Coal/Steam power generation for trains was seen as a super polluting thing and unwanted in cities anymore.

Same thing is happening again, this time it is the combustion's engine turn to get replaced with something cleaner

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#43

Post by kortilla »

notthemessiah wrote: post #36
aardvarkr wrote: post #31

Is no one pointing out that this isn’t the part that makes replacing fossil fuels hard? This is focusing on a completely irrelevant metric. It’s a great motivator for why we need to shift but it has no impact on how hard it will be to replace oil. There’s 100 practical reason for why it’s hard, namely that clean energy sources are not under our direct control to scale up and down as we need more/less. We can’t tell t…

This problem is way overstated, as most fossil fuel and nuclear power can't be easily or efficiently ramped down either. We also have energy storage technologies other than batteries: the most common being pumped-storage hydroelectricity (basically a reversible hydroelectric dam, where we pump water up during excess power usage and use the generators during high demand).

Natural gas absolutely can be ramped up and down and that’s critical to the stability of our grid. Just because there are other fossil fuel plants that can’t doesn’t somehow downplay the critical nature of peaker plants.

> We also have energy storage technologies other than batteries: the most common being pumped-storage hydroelectricity

These take tons of land and aren’t really anything like reverse hydro electric dams because if you tried to reverse a dam during high production you will be running a river dry and run out of water quickly.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#44

Post by kortilla »

toomuchtodo wrote: post #40
aardvarkr wrote: post #31

Is no one pointing out that this isn’t the part that makes replacing fossil fuels hard? This is focusing on a completely irrelevant metric. It’s a great motivator for why we need to shift but it has no impact on how hard it will be to replace oil. There’s 100 practical reason for why it’s hard, namely that clean energy sources are not under our direct control to scale up and down as we need more/less. We can’t tell t…

South Australia already has days when solar alone is providing most of it's power [1] [2]. It's not that hard. You scale up renewables, and build curtailing (throwing away excess clean energy) into your cost model (until storage gets cheaper, which it will; Tesla is shipping almost 800 MW of utility scale battery storage per quarter). Australia's entirely grid will be clean by 2030 at their current rate of renewables…

> Let us not use edge cases to guide our path forward.

Funny you should say that after presenting an edge case.

In North America during the winter the sun is setting during peak demand in the Northern states. That means we need to overbuild wind so much that we can run entirely on wind on non-windy days. The economics do not support that.

Storage is critical to make the US case work.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#45

Post by toomuchtodo »

kortilla wrote: post #44
toomuchtodo wrote: post #40

Earlier quoted context omitted.

South Australia already has days when solar alone is providing most of it's power [1] [2]. It's not that hard. You scale up renewables, and build curtailing (throwing away excess clean energy) into your cost model (until storage gets cheaper, which it will; Tesla is shipping almost 800 MW of utility scale battery storage per quarter). Australia's entirely grid will be clean by 2030 at their current rate of renewables…

> Let us not use edge cases to guide our path forward. Funny you should say that after presenting an edge case. In North America during the winter the sun is setting during peak demand in the Northern states. That means we need to overbuild wind so much that we can run entirely on wind on non-windy days. The economics do not support that. Storage is critical to make the US case work.

Edge cases are the Arctic Circle. Naysayers keep naysaying while it's being done [1]. Enough sunlight falls on the Earth in an hour to power the world for a year, and there's roughly 200GW of solar PV manufacturing capacity globally.

[1] https://www.eia.gov/electricity/monthly/#tabs_unit-4 (Maps, right hand side showing retirements and commissioning; note wind is green, solar is yellow)

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#46

Post by philipkglass »

robertlagrant wrote: post #27

The article seems incomplete. Sure we may be burning three times more coal than we'd have to if we could perfectly convert it to energy. That has literally never factored into an argument I've seen about renewables - it's always "we currently produce X GigaWatts 24x7, and renewables don't let us do that". Saying we burn coal at 30% efficiency isn't addressing anything useful. And it's one of those articles where many…

It's a factor in arguments where people say "we don't need to just clean up electricity, we need to replace all fossil energy." They're usually referring to primary energy in these arguments. If you look at barrels of oil consumed per day in the US, then just plug the barrel-of-oil numbers into a unit converter to see how many terawatt hours it comes to, it looks hopeless to put a dent in oil consumption with electric vehicles and renewable electricity.

But as the Bloomberg article points out, we don't need a 1:1 replacement of joules from fossil fuels with joules from non-fossil energy. If everyone currently driving a Toyota Corolla started driving a wind-charged battery electric vehicle instead, the total energy consumed would shrink dramatically without any behavioral changes. Most of the oil energy demanded by those Corollas is simply wasted as heat.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#47

Post by lake-effect »

“Electrical devices can sometimes offer higher than 100% efficiency,” said BNEF analyst Matthias Kimmel. That might seem odd. How can there be more energy as output than input? But that’s exactly what heat pumps and air conditioners do. They use electricity to shift heat from the outside to inside, or vice-versa, and typically provide three units of energy service for one unit of energy input, meaning an efficiency of 300%."

Article seems to arguing against basic thermodynamic laws. Air conditioners and heat pumps do not output more energy than they consume. You can't move heat around without expending lots of energy. I'm suspicious this is just uptalk trying convince people renewables can replace fossil fuels without any new data, just confusing lines of arguments.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#48

Post by kortilla »

toomuchtodo wrote: post #45
kortilla wrote: post #44

Earlier quoted context omitted.

> Let us not use edge cases to guide our path forward. Funny you should say that after presenting an edge case. In North America during the winter the sun is setting during peak demand in the Northern states. That means we need to overbuild wind so much that we can run entirely on wind on non-windy days. The economics do not support that. Storage is critical to make the US case work.

Edge cases are the Arctic Circle. Naysayers keep naysaying while it's being done [1]. Enough sunlight falls on the Earth in an hour to power the world for a year, and there's roughly 200GW of solar PV manufacturing capacity globally. [1] https://www.eia.gov/electricity/monthly/#tabs_unit-4 (Maps, right hand side showing retirements and commissioning; note wind is green, solar is yellow)

> Enough sunlight falls on the Earth in an hour

This isn’t relevant because we don’t have transmission from where the sun is at a given point in time to where the electricity is needed.

It’s like having enough nuclear plants in Fiji to power the world and calling this a “solved problem”.

We would need a global grid and solar more than 2X built for demand to handle the fact that the earth rotates and that there will be clouds on average.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#49

Post by toomuchtodo »

kortilla wrote: post #48
toomuchtodo wrote: post #45

Earlier quoted context omitted.

Edge cases are the Arctic Circle. Naysayers keep naysaying while it's being done [1]. Enough sunlight falls on the Earth in an hour to power the world for a year, and there's roughly 200GW of solar PV manufacturing capacity globally. [1] https://www.eia.gov/electricity/monthly/#tabs_unit-4 (Maps, right hand side showing retirements and commissioning; note wind is green, solar is yellow)

> Enough sunlight falls on the Earth in an hour This isn’t relevant because we don’t have transmission from where the sun is at a given point in time to where the electricity is needed. It’s like having enough nuclear plants in Fiji to power the world and calling this a “solved problem”. We would need a global grid and solar more than 2X built for demand to handle the fact that the earth rotates and that there will b…

Yes, we're going to need more renewables to support peak demand, I thought I mentioned that above (ie curtailment). A global grid is not necessary, although a more integrated grid (likely long haul HVDC transmission lines [1]), storage (utility and distributed), and demand response is [2].

[1] https://publications.jrc.ec.europa.eu/repository/bitstream/J... (warning: pdf, "HVDC Submarine Power Cables in the World")

[2] https://www.energy.gov/oe/activities/technology-development/...

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#50

Post by xboxnolifes »

lake-effect wrote: post #47

“Electrical devices can sometimes offer higher than 100% efficiency,” said BNEF analyst Matthias Kimmel. That might seem odd. How can there be more energy as output than input? But that’s exactly what heat pumps and air conditioners do. They use electricity to shift heat from the outside to inside, or vice-versa, and typically provide three units of energy service for one unit of energy input, meaning an efficiency o…

This came up in the last hackernews post I've seen on the topic. It essentially boiled down to that air conditioner efficiency (and similar machines) is measured using a different formula than energy conversion efficiency.
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