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Sustainable Energy without the Hot Air (Revised, Community Edition)

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Re: Sustainable Energy without the Hot Air (Revised, Community Edition)

#31

Post by kergonath »

bryanlarsen wrote: post #25
lucb1e wrote: post #14

Earlier quoted context omitted.

I don't understand what you mean. Just because it's cheap, how is it suddenly not a consideration anymore whether we want to fill a large share of nature or farmland with PV, batteries, wind? There are more considerations than cost. Also because one needs to keep in mind that renewable electricity is only about 10% of the energy demand. I sometimes see headlines like "61% of electricity in Germany came from wind last…

Supplying the US using solely solar power would only require 20,000 square miles of land. We have more land in parking lots. The battery land requirements are approximately 1 square mile. And wind requirements are effectively 0 since wind can very easily co-exist with other land usages.

Getting rid of parking lots (and the energy- and ressources-hungry individual cars sitting on them) would certainly be a big step forward to a sustainable future.

Re: Sustainable Energy without the Hot Air (Revised, Community Edition)

#32

Post by kergonath »

derriz wrote: post #15
DennisP wrote: post #12

Earlier quoted context omitted.

They've gotten cheaper by an order of magnitude, but their basic physical characteristics haven't changed that much. A big point of the book is to show what it looks like to really deploy this stuff at the necessary scale.

The issue is that we now have real experience of deploying this stuff at scale and integrating intermittent sources into grids. Many countries in Europe have 30% or more of their electricity supplied by intermittent but it turns out that the integration problem isn't as difficult as envisaged. The consensus amongst engineers is that up to about 70% is manageable without any big tech breakthroughs. Network reliability…

> Many countries in Europe have 30% or more of their electricity supplied by intermittent but it turns out that the integration problem isn't as difficult as envisaged.

True. It’s very easy when you can tap your neighbour’s power plants when you need. The problem is a bit different when all the neighbours have the same problems at the same time.

Re: Sustainable Energy without the Hot Air (Revised, Community Edition)

#33

Post by lucb1e »

bryanlarsen wrote: post #25
lucb1e wrote: post #14

Earlier quoted context omitted.

I don't understand what you mean. Just because it's cheap, how is it suddenly not a consideration anymore whether we want to fill a large share of nature or farmland with PV, batteries, wind? There are more considerations than cost. Also because one needs to keep in mind that renewable electricity is only about 10% of the energy demand. I sometimes see headlines like "61% of electricity in Germany came from wind last…

Supplying the US using solely solar power would only require 20,000 square miles of land. We have more land in parking lots. The battery land requirements are approximately 1 square mile. And wind requirements are effectively 0 since wind can very easily co-exist with other land usages.

That's fair; I'm mainly looking at this from a western European perspective. If you're from a more southernly country with large unused deserts... that tends to help.

Re: Sustainable Energy without the Hot Air (Revised, Community Edition)

#34

Post by rufuspollock »

algo_trader wrote: post #24
oezi wrote: post #10

Earlier quoted context omitted.

And did the general conclusion change that wind wouldn't be able to provide more than even half the energy we need for transport?

Yes. The conclusion has changed! Electric cars are ridiculously efficient. A 100kwh tesla drives approx 500km. So 50km/day/car needs just 10kwh. The UK also has 2 persons per car (plus additional cats and dogs..) So just the on-shore book projection is already enough AND only requires a tenth of the turbines. Lets keep nuclear as well. Invest in efficiency. Lots of hard work ahead. But we are probably closer to "prob…

Just to flag that MacKay already estimated (in 2008) a Tesla at 15kwh per 100km (actually better than you have here). See Fig 20.22 on https://climate.lifeitself.us/without-hot-air/chap20/

Re: Sustainable Energy without the Hot Air (Revised, Community Edition)

#35

Post by jetbooster »

kergonath wrote: post #31
bryanlarsen wrote: post #25

Earlier quoted context omitted.

Supplying the US using solely solar power would only require 20,000 square miles of land. We have more land in parking lots. The battery land requirements are approximately 1 square mile. And wind requirements are effectively 0 since wind can very easily co-exist with other land usages.

Getting rid of parking lots (and the energy- and ressources-hungry individual cars sitting on them) would certainly be a big step forward to a sustainable future.

I don't think they were suggesting getting rid of the the car parks, but rather putting solar over the top of them. Which would also reduce the amount of petrol used to AC the car when you get back in it too (though this effect is probably negligible)

Re: Sustainable Energy without the Hot Air (Revised, Community Edition)

#36

Post by mcot2 »

It sounds like this should have a date attached to it as the numbers are quite outdated for todays world. This did have some good data for back when it was written of course.

* An efficient EV will do less than 12kWh/100km these days.

* Utility scale solar pv cost declines have been dramatic. It is now the cheapest form of new energy to deploy.

* Developments in deep water off-shore wind have led to much larger turbines which are capturing more wind energy for longer periods of time.

* Large scale batteries are now viable as a storage mechanism for renewables and are going to rapidly replace things like peaker plants.

* Lots of new research is happening with Nuclear like thorium/molten-salt reactors which will still be important for baseload generation.

Re: Sustainable Energy without the Hot Air (Revised, Community Edition)

#37

Post by selimthegrim »

algo_trader wrote: post #8
phreeza wrote: post #5

Earlier quoted context omitted.

It would be fantastic to turn the chapters into Templates where one has to plug in the relevant parameters for a country and see the calculations for that country.

And multiple PhD students have done so! For example, the Stanford/Jacobson study on powering the world with wind/solar/water. Some results were famously silly, such as filing Finland with solar panels, or adding the cost of nuclear war to nuclear reactors. Jacobson sued other academics then backed down. The point is, 5-10 years on, these models turned out to be over pessimistic! Australia doesn't need fancy modelling…

Has Jacobson stopped suing people though

Re: Sustainable Energy without the Hot Air (Revised, Community Edition)

#38

Post by derriz »

kergonath wrote: post #32
derriz wrote: post #15

Earlier quoted context omitted.

The issue is that we now have real experience of deploying this stuff at scale and integrating intermittent sources into grids. Many countries in Europe have 30% or more of their electricity supplied by intermittent but it turns out that the integration problem isn't as difficult as envisaged. The consensus amongst engineers is that up to about 70% is manageable without any big tech breakthroughs. Network reliability…

> Many countries in Europe have 30% or more of their electricity supplied by intermittent but it turns out that the integration problem isn't as difficult as envisaged. True. It’s very easy when you can tap your neighbour’s power plants when you need. The problem is a bit different when all the neighbours have the same problems at the same time.

Of course interconnection is a big help, but transmission isn't "free" or unlimited, the flows between individual European countries is typically a small fraction (less than 10%) of the national consumption and generation.

And there are cases like Ireland which has its own grid - with very limited external interconnection - and yet achieved 42% renewable share last year.

Techniques/engineering/theory for integrating intermittent sources has advanced considerably in the last ten years.

Re: Sustainable Energy without the Hot Air (Revised, Community Edition)

#39

Post by zbrozek »

lucb1e wrote: post #28
johnny53169 wrote: post #22

Earlier quoted context omitted.

> (3.) carbon capture, and one gets to 75% emissions reduction with less than one percent of cost increase Carbon capture and less than one percent cost increase looks suspect to me

Agreed. I didn't use it at first because I thought it would be cheaper to just reduce emissions than undo emissions, at least up until this 80% goal that the site poses. Without any carbon capture, you're still at 61% emissions reduction and the cost actually decreases by 0.8% from today rather than increasing by 0.6%. If you get to 61% with the only change being "build nuclear and make use of it" (no lifestyle chang…

Surely there are studies of LCOE for both when trying to produce baseload capacity. Personally, I suspect nuclear construction costs are dominant, but that should also be addressible through improvements in technology and policy.

Re: Sustainable Energy without the Hot Air (Revised, Community Edition)

#40

Post by [deleted] »

wiz21c wrote: post #4
algo_trader wrote: post #2

Alas, this is probably pointless. Some technologies (PV, batteries, wind) have improved by an order of magnitude - and swamp out all other considerations. EDIT: to be clear, i loved the original book, and have re-read it several times over the years.

FTBook: > Wind turbines are getting bigger all the time. Do bigger wind turbines change this chapter’s answer? > Chapter B explains. Bigger wind turbines deliver financial economies of scale, but they don’t greatly increase the total power per unit land area, because bigger windmills have to be spaced further apart. A wind farm that’s twice as tall will deliver roughly 30% more power. So, did wind turbine production…

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