[Petrochemicals (OP)]

As I see it, windmills cannot supply the prospective world population with the continuous 5 - 7 kW per capita always on tap,

I think that is a bit much Alan. True enough we only use 20 percent of our of our energy in electricity, about 35gw in the uk and we do not provide most of the energy in our cunsumed products because we no longer have a manufacturing base, but I think that's a little much.

I am aware that energy and power GW are not identical.

[Bored chemist]

As I see it, windmills cannot supply the prospective world population

You already said that you don't know how many that is.
So you can't calculate the power requirements and you can't count the windmills needed.

Why are my concerns and solutions based on a couple of small islands? Because this is (a) where I live and (b) where the best innovations (steam engine, railways, industrial revolution, antibiotics, vaccination, civil nuclear power, programmable computers, the English language, soccer, rugby, cricket, tennis, golf....) come from.

Among the innovations are state pensions and free birth control; That's largely why anything that happens in the UK is largely irrelevant.

The medium-term problem

What timescale is that?
Is it long enough for the grandmothers and mothers to die and invalidate your argument on population numbers?
in the long run, the women need to have an average of (about)1 daughter to maintain a constant population and that pretty much means two children. In the UK the number is below 2 and so the population will eventually shrink.
You seem to be happy to be short termist about something, but not others.

[alancalverd]

1. Total UK power consumption before COVID was about 5 kW per capita - 325 GW total. We currently have about 15 GW of installed wind power capacity, delivering on average 20% of its rated output. so to generate 325GW average we will need 325 x 5 /15 = 108 times as many windmills as we currently have, plus sufficient storage to keep everything running when the wind doesn't blow, plus enough surplus generating capacity to ensure that the storage can be replenished whilst we are still using electricity when the wind does blow, so maybe 200 times as many windmills as at present, assuming that they can all be placed optimally - though market forces suggest that all the best spots have been taken by now. And of course we need to upgrade the grid to carry 6 times its present load, and distribute it to places that currently run on gas or oil, and replace all the gas and oil burning machines with elecrtical ones.

And that is the scene for an advanced industrial society with plenty of wind.The rest of the world is mostly starting from a much lower base.

2. Anything that happens in the UK is relevant to the UK. Whether the rest of the world wants to follow is pretty much up to them, as we don't have a empire to insist.

3. So why has the UK population increased  by an average of 0.4% per year since 1950, and is projected to continue to rise until 2100? The reason is simple: whilst the birth rate has remained fairly constant  at about 1.2% per annum, the death rate has decreased from 1.2 to 0.9% pa. The remaining 0.1% can be ascribed to net immigration. 

[Bored chemist]

The reason is simple: whilst the birth rate has remained fairly constant  at about 1.2% per annum, the death rate has decreased from 1.2 to 0.9% pa.

Good to see that you have recognised the importance of the birth rate exceeding the death rate.

[alancalverd]

And for as long as we increase life expectancy, we need to continue to decrease the birth rate if the population is not to increase. So the next question is what level of population is indefinitely sustainable,and  how do we attain it?

[Petrochemicals (OP)]

1. Total UK power consumption before COVID was about 5 kW per capita - 325 GW total. We currently have about 15 GW of installed wind power capacity, delivering on average 20% of its rated output. so to generate 325GW average we will need 325 x 5 /15 = 108 times as many windmills as we currently have,

I think that is a bit high, I do accept that wind power is only 20 percent of capacity, but burning fossil fuel is not 100 percent direct energy delivery, this will aslo need to be factored. UK energy demand is also factored to 80 percent non electrical fossil fuel use, which varies between about 80-90 percent efficient for heat and hot water use, to somewhere around 33-45 for vehicles.

I get a figure of 4kw demand for the uk, averaging around 0.7 conversion gives a convenient 3kw demand per person of utilised energy.

[alancalverd]

https://ourworldindata.org/grapher/per-capita-energy-use works out at 5.36kW per capita for the UK pre-covid. Even if we only needed 50 times as many windmills, and a storage and distribution system and total conversion of all vehicles, machines and heating systems happened at zero cost by magic, I don't see where the windmills might be put.

[Bored chemist]

5.36kW per capita for the UK

I don't see where the windmills might be put.

Well, I could put mine on my roof.
https://uk.rs-online.com/web/p/wind-turbines/9064242?cm_mmc=UK-PLA-DS3A-_-google-_-CSS_UK_EN_Fallback-_-All+Products-_-9064242&matchtype=&pla-293946777986&gclid=CjwKCAiAgvKQBhBbEiwAaPQw3Ok2_x3q7S8COXLc8vzIQ8fZbuihjXJeaXO7VsIZDVUJprxJpgKANRoCdTUQAvD_BwE&gclsrc=aw.ds

I realise I'm lucky to own my own house and that I'd need several (and solar PV and heating panels) to take account of when the wind's not blowing, but it does put the problem into perspective

[alancalverd]

That one will deliver about 1kWh per day, according to its data sheet. Enough to drive your electric car 3 miles in summer, or heat a bath every 3 days. Provided, of course, that you strengthen the roof, don't have close neighbors with the same idea or a taller house, and don't mind the noise.

[Bored chemist]

That one will deliver about 1kWh per day, according to its data sheet. Enough to drive your electric car 3 miles in summer, or heat a bath every 3 days.

So... you didn't understand this bit.

(and solar PV and heating panels)

And I still don't have a car.

[Petrochemicals (OP)]

https://ourworldindata.org/grapher/per-capita-energy-use works out at 5.36kW per capita for the UK pre-covid. Even if we only needed 50 times as many windmills, and a storage and distribution system and total conversion of all vehicles, machines and heating systems happened at zero cost by magic, I don't see where the windmills might be put.

Yep, far too many windmills, and probably far too much connecting infrastructure, that is a lot of cables switchgear etc.

I think the discrepancy is raw energy, power delivery, efficiency etc.

[alancalverd]

So... you didn't understand this bit.
Quote from: Bored chemist on Today at 18:06:53
(and solar PV and heating panels)

Not sure about heating panels but an average UK house roof covered with PV panels generates 350W averaged over a year, less than a tenth of your needs. Probably better to cover the roof with water heating panels but they seem to be out of fashion these days. And folk who live in a block of flats really can't benefit from local solar or wind - same roof area, maybe 10 times as many people! 

Not having a car probably means that you rely on buses and trains. Very fuel-efficient when full, absurdly wasteful when empty, and annoying if the Powers that Be don't run empty-ish trains outside peak hours. Remember my objective (and that of many others) is a Western  standard of convenience and comfort, which doesn't involve walking more than a couple of miles to go shopping.

[Bored chemist]

And folk who live in a block of flats really can't benefit from local solar or wind - same roof area, maybe 10 times as many people! 

So... you felt the need to repeat this bit.

I realise I'm lucky to own my own house

[Petrochemicals (OP)]

https://ourworldindata.org/grapher/per-capita-energy-use works out at 5.36kW per capita for the UK pre-covid. Even if we only needed 50 times as many windmills, and a storage and distribution system and total conversion of all vehicles, machines and heating systems happened at zero cost by magic, I don't see where the windmills might be put.

Does this include aircraft fuel and goods manufacture. Aircraft fueling could be considered as international.

So... you didn't understand this bit.
Quote from: Bored chemist on Today at 18:06:53
(and solar PV and heating panels)

Not sure about heating panels but an average UK house roof covered with PV panels generates 350W averaged over a year, less than a tenth of your needs.

If 30 million buildings have them that is 100 terrawatt hours Alan, that is suprisingly good.

[alancalverd]

Does this include aircraft fuel and goods manufacture. Aircraft fueling could be considered as international.

It is reasonable to assume that as many aircraft leave the UK as arrive here, and good management means you arrive almost empty. Thus all fuel delivered to aircraft in the UK may be assumed to be consumed by UK citizens.

If 30 million buildings have them that is 100 terrawatt hours Alan, that is suprisingly good.

If the 30 million buildings contain 65,000,000 citizens (which they do), with one windmill on each building, that equates to 162 watts per capita, well short of the 4 - 5000 we need. And you still need storage capacity.

[wolfekeeper]

So very much misinformation in this thread. The average car goes 30 miles per day. To produce the electricity to make an average electric car go 30 miles needs about 10 kWh. A solar panel in the UK produces about 1000 kWh per installed kW, so to make 10 kWh per day needs 3 kW peak. That's 15 square metres. Which isn't actually that much. The point isn't that every house or block of flats will need this or that every house ought to get a windmill (that's actually a spectacularly bad idea, small windmills are insanely inefficient, costly and even dangerous with their whirling blades.)

Of course solar will produce more electricity in the summer, and less in the winter, but almost everyone in the UK is on the grid, and sharing electricity is the entire whole point of the grid. And off-shore wind produces more electricity in the winter and less in the summer, so it averages out.

I do accept that wind power is only 20 percent of capacity

Wrong, a lot more than that. The UK gets virtually 25% of its electricity from wind (or did in 2020, and it's increasing), and the capacity factor of offshore wind power in the UK is about 40% now, so by nameplate capacity it's going to be a lot more than 20%.

[Petrochemicals (OP)]

. A solar panel in the UK produces about 1000 kWh per installed kW, so to make 10 kWh per day needs 3 kW peak. That's 15 square metres.

I do not follow

I do accept that wind power is only 20 percent of capacity

Wrong, a lot more than that. The UK gets virtually 25% of its electricity from wind (or did in 2020, and it's increasing), and the capacity factor of offshore wind power in the UK is about 40% now, so by nameplate capacity it's going to be a lot more than 20%.

Wrong seems a little bit judgemental. 40 percent of the uks 330twh electrical yearly demand is 132terrawatt hours.

[Petrochemicals (OP)]

Does this include aircraft fuel and goods manufacture. Aircraft fueling could be considered as international.

It is reasonable to assume that as many aircraft leave the UK as arrive here, and good management means you arrive almost empty. Thus all fuel delivered to aircraft in the UK may be assumed to be consumed by UK citizens.

But is that international or domestic listing. For some reason I think that figures, especially for government figures relating to government promises or favoured industries may be massaged, but maybe I need to take a leaf from your book and have more faith.

If 30 million buildings have them that is 100 terrawatt hours Alan, that is suprisingly good.

If the 30 million buildings contain 65,000,000 citizens (which they do), with one windmill on each building, that equates to 162 watts per capita, well short of the 4 - 5000 we need. And you still need storage capacity. 

Yep, but if we increace the solar on buildings throughout, ie factory roofs and offices you could have it doubled, storage would help we could up the pumped storage at our reservoirs, but the solar potential is easily judged by sticking your head out of the window.  Demand for electric is about 500 Watts a person.

[alancalverd]

But is that international or domestic listing.

The total energy consumption figure I quoted for the UK includes all known fuels for all purposes. Its actually surprisingly low per capita compared with some of our neighbors. 

[alancalverd]

A solar panel in the UK produces about 1000 kWh per installed kW, so to make 10 kWh per day needs 3 kW peak. That's 15 square metres.

So far, entirely credible. Problem is that the average UK citizen currently consumes almost 100 kWh per day and doesn't have 15 square meters of optimally aligned roof. To meet UK energy demand from solar panels, you would need to cover about 5% of the country. That is, every existing road and building - except that half of the buildings are facing the wrong way..  Almost feasible, if you started 50 years ago. And you still need to install storage and distribution, and convert all your existing machinery to run on electricity, so the time to do it was about 150 years ago.