Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

climate.lifeitself.us

Post reply on HN
Print view View original

21–30 of 138 posts

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

#21

Post by cbmuser »

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…

Germany has a large share (50%) of renewables and their specific CO2 emissions per kWh are up to ten times higher as compared to France with 70% nuclear.

Volatile renewables don’t effectively help to reduce greenhouse gas emissions.

https://ourworldindata.org/grapher/ghg-emissions-by-sector?t...

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

#22

Post by johnny53169 »

lucb1e wrote: post #20
ycomb-uit-co-uk wrote: post #6

Have a look at http://2050-calculator-tool.decc.gov.uk/ (I was David's Editor for "Sustainable Energy - without the hot air". There's been quite a bit of interest in updating the book, but there are obvious difficulties. If have suggestions, let me know. Niall Mansfield sewtha-2.0@uit.co.uk )

I wonder if this is correct. Setting the nuclear slider to max single-handedly reduces emissions by 30%, decreases energy costs rather than increases, does not require land use change, improves air quality, and also reduces electricity demand by using the waste heat for district heating. Now add: (1.) electrification of freight transport, (2.) tackling the (relatively) quick wins in industry electrification, and (3.)…

> (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

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

#23

Post by samch93 »

It‘s such a tragedy that he died so young. Prof Mackay was a role model who impacted our world in many positive ways (e.g. his work in information theory, Bayesian statistics, environmental science). I recommend his lecture on information theory which is available on youtube [1]. He also documented the progress of his cancer very detailed on his blog [2], which is a very interesting (and sad) read.

[1] https://youtu.be/BCiZc0n6COY

[2] http://itila.blogspot.com/?m=1

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

#24

Post by algo_trader »

oezi wrote: post #10
algo_trader wrote: post #7

Earlier quoted context omitted.

Amazingly, yes! Turbines have gone from 1-2MW to 10-16MW Capacity factors have gone from 20% to 50%-60% Annual additions gave gone from sub-GW to 70GW last year And with turbine spacing of 1km you can actually do stuff with the land in between. On the other hand, transmission projects still take 10-20 years, and new transmission projects are often over booked by 300%-400% before they are even started.

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 "problem solved" than to "civilization collapse". Cheers.

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

#25

Post by bryanlarsen »

lucb1e wrote: post #14
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.

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.

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

#26

Post by [deleted] »

542458 wrote: post #11

One thing that feels a bit strange to me is that he uses timelines of 1000 years when calculating nuclear reserves. I don’t believe we need a plan for the next 1000 years - think of what our understanding of power generation and transmission was a millennium ago. Assuming that we will still be using the same technologies in 1000 years seems a bit pessimistic to me.

[deleted]

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

#27

Post by rufuspollock »

ycomb-uit-co-uk wrote: post #6

Have a look at http://2050-calculator-tool.decc.gov.uk/ (I was David's Editor for "Sustainable Energy - without the hot air". There's been quite a bit of interest in updating the book, but there are obvious difficulties. If have suggestions, let me know. Niall Mansfield sewtha-2.0@uit.co.uk )

Thanks Niall - updating the book is exactly what we are hoping to do and still thinking the best form for that. Re that tool i've been in correspondence with one of the other creators re trying to understand the source code etc - see https://github.com/life-itself/climate/issues/2

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

#28

Post by lucb1e »

johnny53169 wrote: post #22
lucb1e wrote: post #20

Earlier quoted context omitted.

I wonder if this is correct. Setting the nuclear slider to max single-handedly reduces emissions by 30%, decreases energy costs rather than increases, does not require land use change, improves air quality, and also reduces electricity demand by using the waste heat for district heating. Now add: (1.) electrification of freight transport, (2.) tackling the (relatively) quick wins in industry electrification, and (3.)…

> (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 changes, no cost changes, no landuse changes), that would be amazing.

Hence my main question is about the nuclear aspect. The argument against nuclear is usually that it's super scary and dangerous (easy enough to disprove that with numbers, so long as you're not talking to someone from germany) and the fallback argument is that it's so expensive now that PV+wind became so much cheaper. This calculator seems to show the opposite of that latter argument (when looking purely at price).

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

#29

Post by rufuspollock »

bjelkeman-again wrote: post #3
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.

David MacKay’s work was for me very important. It showed how one should do a systems analysis for a country to understand how one can achieve the change required. I was astonished when I talked to several of the leading people responsible for energy policy in several political parties in my country, to find they really had no clue about what they where doing on a systems level. I think that updating this book is not…

> It showed how one should do a systems analysis for a country to understand how one can achieve the change required. I was astonished when I talked to several of the leading people responsible for energy policy in several political parties in my country, to find they really had no clue about what they where doing on a systems level.

Massive +1. And i agree that perhaps "reusing" the book would be useful. E.g. take the key factual approach and update analyses for particular technologies and then plug those together - which to some extent is what the pathway calculator did which is why it is worth trying to get the source for that https://github.com/life-itself/climate/issues/2

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

#30

Post by kergonath »

542458 wrote: post #11

One thing that feels a bit strange to me is that he uses timelines of 1000 years when calculating nuclear reserves. I don’t believe we need a plan for the next 1000 years - think of what our understanding of power generation and transmission was a millennium ago. Assuming that we will still be using the same technologies in 1000 years seems a bit pessimistic to me.

> One thing that feels a bit strange to me is that he uses timelines of 1000 years when calculating nuclear reserves.

Not really. Uranium and thorium are insanely energy dense and whilst it’s obviously impossible to predict energy use a millenium from now, it could handle more than a couple of centuries of exponential growth of energy consumption. Then there are things like fuels made of natural isotopes (so no enrichment needed) and breeder reactors that can run off fission products (aka “waste”), which are not used much today, but are closer to readiness than things like carbon capture.

Post reply on HN