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  4. How can renewable energy farms provide 24-hour power?
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How can renewable energy farms provide 24-hour power?

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Offline Scottish Scientist

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Re: How can renewable energy farms provide 24-hour power?
« Reply #20 on: 08/04/2015 22:46:23 »
Hi chiralSPO and thanks for your feedback.

Quote from: chiralSPO on 08/04/2015 20:24:28
1400 GWh (5.04x1015 J)
Check.
1400 GWh = 1.4TWh = 58.33 GW-days

Quote from: chiralSPO on 08/04/2015 20:24:28
of pumped hydro storage would be quite an engineering feat!
This is 1960s technology. Technically, it is very easy to do and not such a big a job either. £37 billion or 3 channel tunnels' worth of work.

Now the wind turbines are more work. 290GW with 12GW installed already leaves 278GW to build and install and at £1.6 billion per GigaWatt (on land) that comes to £445 billion worth of turbines or 37 channel tunnels' worth.

So the wind turbines are far more of an engineering feat.

Quote from: chiralSPO on 08/04/2015 20:24:28
Even assuming 100% efficiency (not a terrible approximation) you would have to have about 1010 m3 (1013 kg) of water pumped up 50 meters. That volume is slightly larger than the average volume of Loch Ness, which is the largest Loch in Scotland (7.4 km3 = 7.4x109 m3)*.

Perhaps we could use an elevation of 300 meters (the height of the Shard, in London) and only 1.67x109 m3 of water (somewhere between the size of Loch Tay and Loch Morar)*.
David JC MacKay in his book "Sustainable Energy - Without the Hot Air" considers finding sites for 1200GWh and reckons it would be tough.
http://www.withouthotair.com/c26/page_192.shtml

David cleverly managed to think of not putting all the water at one site though which makes it a lot less tough.

300 metres of head is typical for pumped-storage though 500 metres is possible too.
http://www.withouthotair.com/c26/page_191.shtml

The pumped-storage hydro scheme at the Cortes-La Muela, Spain hydroelectric power plant has a head of 524m and impounds a water of volume of 23Hm3 = 23 x 106m3 with a mass of 23 x 109Kg.



Which represents a stored energy maximum of mgh = 23 x 109 x 9.81 x 523 = 1.18 x 1014J or 32.8 GWh. A similar amount of energy is planned by the SSE for their pumped-storage hydro scheme for Coire Glas, Scotland.
http://sse.com/whatwedo/ourprojectsandassets/renewables/CoireGlas/

So only 1400/32.8 = 43 Cortes-La Muelas or 1400/30 47 Coire Glases. I should point out that unlike Cortes La Muela which is pretty much maxed out, the site at Coire Glas - if the design was maxed out in the same fashion - could host a much bigger reservoir there - not 1400 GWh certainly - but 1/3rd of that possibly.

So if three sites like Coire Glas could site our needs for pumped-storage, I don't think it is as tough as David MacKay claims.

Time for the tough to get going.
Quote from: chiralSPO on 08/04/2015 20:24:28
On the other hand, 1400 GWh of electrochemical energy could be stored in 1.4x105 m3 of zinc metal (and the air needed to react with it). Not a small volume, certainly, but four or five orders of magnitude smaller than for pumped hydro.

Well pumped-storage hydro is the method of choice for electricity grid energy storage.

Thanks again for your feedback chiralSPO!


 
« Last Edit: 08/04/2015 23:20:24 by Scottish Scientist »
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Re: How can renewable energy farms provide 24-hour power?
« Reply #21 on: 09/04/2015 00:13:39 »
Quote
My model has been tested on real gridwatch data for 2014 and the more cost effective solution is not "14 days' of storage capacity" but only a bit more than 1 day of storage and more wind power.

and that, I think, is the fatal flaw in all proposals for wind power. During a winter anticyclone, the whole of the UK (and most of Europe) can be covered by a high pressure zone with average winds of 5 kt or less, for at least a week at a time. "More wind power" won't deliver any power when there's no wind! You need to consider a supply that, in effect, can go to zero for several days at a time, and when it recovers, you need to supply all the present demand plus enough power to recharge your storage system before the next shutdown. Thus your installed primary generating capacity needs to be about 6 times average demand, plus 1 x peak demand for the pumped storage units. Ignoring the cost of building the storage ponds and extra grid capacity, this means that you have to install 7 times the present generating capacity in order to meet present demand from renewables instead of fossil and nuclear generators. 

Saying that
Quote
Also I don't see an urgent need to build additional renewable reserves since it would be acceptable at least initially to use other types of capacity - such as biomass fuel burning or even fossil-fuel burning power stations as a reserve.
is frankly ignoring the weight of the elephant. As I understand it, current biomass generators in the UK are net negative - the energy required to transport and process the fuel is more than they produce - and any "reserve" station has to recoup its costs from unplanned and intermittent running, which makes even gas an uneconomic investment. And it's intellectually dishonest! You can't start off with a plan for 100% renewables and then say "plus a bit of coal in case it goes wrong".

My preference would be to reinstate low-pressure gasholders and use wind power to generate hydrogen which we distribute through the existing gas grid. And before the usual smartasses tell us about the difficulties and dangers of hydrogen, let me remind them that until 1963, the gas grid contained 50% hydrogen: the dangerous stuff was 10% carbon monoxide.
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Re: How can renewable energy farms provide 24-hour power?
« Reply #22 on: 09/04/2015 01:33:29 »
Quote from: alancalverd on 09/04/2015 00:13:39
Quote
My model has been tested on real gridwatch data for 2014 and the more cost effective solution is not "14 days' of storage capacity" but only a bit more than 1 day of storage and more wind power.

and that, I think, is the fatal flaw in all proposals for wind power.
No testing my model on a whole year of real world demand and wind power data demonstrates there's no fatal flaw.

Quote from: alancalverd on 09/04/2015 00:13:39
During a winter anticyclone, the whole of the UK (and most of Europe) can be covered by a high pressure zone with average winds of 5 kt or less, for at least a week at a time. "More wind power" won't deliver any power when there's no wind! You need to consider a supply that, in effect, can go to zero for several days at a time, and when it recovers, you need to supply all the present demand plus enough power to recharge your storage system before the next shutdown. Thus your installed primary generating capacity needs to be about 6 times average demand, plus 1 x peak demand for the pumped storage units. Ignoring the cost of building the storage ponds and extra grid capacity, this means that you have to install 7 times the present generating capacity in order to meet present demand from renewables instead of fossil and nuclear generators.
Well I tested my model on all the data from 2014, including the winter months.

Actually, as this graph of the January modelling shows, there was no such shortage of wind in January 2014.


Click for full size image - https://scottishscientist.files.wordpress.com/2015/04/windpumpedstorage_january_b1.jpg

The biggest lull in the wind in 2014 was pointed to on this "Idiocy of Renewables" webpage.

"92 Continuous Days of LoLo Wind - That's EverSoLo Electricity from Wind Turbines!"
http://idiocyofrenewables.blogspot.co.uk/2014/10/92-continuous-days-of-lolo-wind-thats.html

To cope with this difficult time, I had to fine tune my solution, but it does work as this graph for June 2014 shows.


Click for full size image - https://scottishscientist.files.wordpress.com/2015/04/windpumpedstorage_june.jpg

But instead of pointing to real data which illustrates a wind condition, you simply wave your hands in a data-free way. That's not scientific Alan.

I admit I have not tested my model on data from all years. Maybe there is data set from Gridwatch which will break my model and force me to increase the wind GW or pumped-storage GWh, but you certainly have not pointed to such a specific data set, have you?

You have not done the scientific thing which the author of the "Idiocy of Renewables" did when he quoted hard data to make his point.

You know Alan, I love a challenge. I really do. If you can point to the data of a very low wind spell in the UK from Gridwatch, I'd be delighted to test out my model on it.


Quote from: alancalverd on 09/04/2015 00:13:39
Saying that
Quote
Also I don't see an urgent need to build additional renewable reserves since it would be acceptable at least initially to use other types of capacity - such as biomass fuel burning or even fossil-fuel burning power stations as a reserve.
is frankly ignoring the weight of the elephant. As I understand it, current biomass generators in the UK are net negative - the energy required to transport and process the fuel is more than they produce
Really? Got some evidence for that? Mankind has long used wood as fuel so maybe they knew something you don't?

Quote from: alancalverd on 09/04/2015 00:13:39
- and any "reserve" station has to recoup its costs from unplanned and intermittent running, which makes even gas an uneconomic investment.
Well the grid can hire power plants to stay on stand-by and pay a premium for emergency power and make reserve stations profitable.

Quote from: alancalverd on 09/04/2015 00:13:39
And it's intellectually dishonest! You can't start off with a plan for 100% renewables and then say "plus a bit of coal in case it goes wrong".
If I had to resort to fossil fuel, gas would be the choice because a) it is a faster start up and b) renewable-generated hydrogen from power-to-gas can be added to the fuel mix.

My plan for Scotland recommends converting the last coal power station in Scotland at Longannet to burn biomass fuel.

I do offer a 100%-renewable 24-hours a day, 7-days a week electricity generation plan but it is much tougher to guarantee 52 weeks a year.

If that's as intellectually dishonest as the "teetotal" man who has one glass of sherry at Christmas, well I can live with that.

Quote from: alancalverd on 09/04/2015 00:13:39
My preference would be to reinstate low-pressure gasholders and use wind power to generate hydrogen which we distribute through the existing gas grid. And before the usual smartasses tell us about the difficulties and dangers of hydrogen, let me remind them that until 1963, the gas grid contained 50% hydrogen: the dangerous stuff was 10% carbon monoxide.
Yes, my plan generates surplus wind power at times of up 60% of maximum wind power. This can be used to produce hydrogen in power-to-gas for injection into the gas grid.

However, it is not as efficient to re-generate electricity from power-to-gas hydrogen as it is from pumped-storage hydro, so we need the pumped-storage as I have described for more efficient energy storage.
« Last Edit: 09/04/2015 01:42:54 by Scottish Scientist »
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Re: How can renewable energy farms provide 24-hour power?
« Reply #23 on: 09/04/2015 08:23:25 »
Quote
You know Alan, I love a challenge. I really do. If you can point to the data of a very low wind spell in the UK from Gridwatch, I'd be delighted to test out my model on it.

As you say, we have 12 GW installed windpower in the UK.

According to Gridwatch, today is the seventh consecutive day with wind power at less than 2GW. In fact the running average is less than 1 GW for the past week.

I think you - or at least your customers - will find 24 hours' storage rather inadequate, even in a mild spring.

I am reminded of the statistician who, on learning that the average depth of the Thames is 3 feet, drowned whilst walking from Chelsea to Battersea.
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Re: How can renewable energy farms provide 24-hour power?
« Reply #24 on: 09/04/2015 11:59:12 »
Quote from: alancalverd on 09/04/2015 08:23:25
Quote
You know Alan, I love a challenge. I really do. If you can point to the data of a very low wind spell in the UK from Gridwatch, I'd be delighted to test out my model on it.

As you say, we have 12 GW installed windpower in the UK.
Yes.

Quote from: alancalverd on 09/04/2015 08:23:25
According to Gridwatch,
Be aware that Gridwatch data for wind power is not what is served from the full 12 GW installed in the UK, but for only just over 50%. So Gridwatch's maximum wind power data reading in 2014 was only 6835 MW on 2014-12-09 19:50:02.

To check this, visit the Gridwatch website http://www.gridwatch.templar.co.uk/
and hover your mouse above the wind power dial and a context pop-up text bubble appears which says ..
Quote
Wind: This is the total contributed by metered wind farms. Wind power contributes another about 50% from embedded (or unmetered) wind turbines that shows only as a drop in demand.

Which also means the demand data is slightly lower than it really is too but that can be discounted for present purposes.

Quote from: alancalverd on 09/04/2015 08:23:25
today is the seventh consecutive day with wind power at less than 2GW. In fact the running average is less than 1 GW for the past week.

As I say, I love a challenge and the low wind period just now is such a challenge, so I've run it through my model - normalised for a case study of the UK this time - and here's the results.


Click for full size image - https://scottishscientist.files.wordpress.com/2015/04/windpumpedstorage_april2015.jpg

So there would still be some water left at this time in the 1400 GWh reservoirs with 290 GW installed wind power, but it is running low admittedly, so we'll have to wait to see if the wind can pick up to save the day or whether I will need to rethink my 1400 GWh / 290 GW recommendation.

Quote from: alancalverd on 09/04/2015 08:23:25
I think you - or at least your customers - will find 24 hours' storage rather inadequate, even in a mild spring.
Remember I have tested these the equivalent of these 1400 GWh / 290 GW specifications (normalised for the case study of Scotland) on the spring of 2014 and it worked.

As you can see for this period in early April 2015, the design specifications of 1400 GWh / 290 GW have managed this period of low wind (so far) for longer than 24 hours of low wind.

This is because 1400GWh is 58.33 GW-days but the daily average of power demand is less than the peak demand of 52.5GW. Demand from April 1 to 9 2015 has varied between a minimum of  25649 MW and a maximum of 43069 MW.

Quote from: alancalverd on 09/04/2015 08:23:25
I am reminded of the statistician who, on learning that the average depth of the Thames is 3 feet, drowned whilst walking from Chelsea to Battersea.
He should have gone to spec-savers.  [:)]
« Last Edit: 09/04/2015 12:19:35 by Scottish Scientist »
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Re: How can renewable energy farms provide 24-hour power?
« Reply #25 on: 10/04/2015 09:09:57 »
This is the 8th consecutive day with wind below 2 GW - your storage system is looking a bit marginal.

However, having addressed the elephant in the room, it is a good time to look at a couple of diplodoci.

Diplodocus 1. Electricity accounts for less than 25% of UK energy consumption. Practically all the rest is direct burning of fossil fuels. So if you replaced all electricity generation with wind, we would still be emitting at least 75% of current carbon dioxide levels, and society would grind to a halt when the oil runs out. If you want to run everything on unreliables, you will need at least 4 times as much generating distribution and storage capacity as your current best estimate, plus an unimaginable capital expenditure on electric transport and heating. As that expenditure will be mandatory, it will have to come from government or the windmill builders. Fat chance.

Diplodocus 2. We use electricity because it is cheapish and reliable. Given that you will need to install at least 3 times overcapacity (possibly 7 times on my assumptions) plus storage facilities in order to approach current levels of reliability, what is the anticipated future unit cost? You need to take into account a 10 - 15 year life for outdoor electromechanical equipment, a sensible rate of return on capital, maintenance costs (I usually estimate 50 - 100% of capital cost over 10 years for a guaranteed uptime maintenance contract. Equipment installed indoors at ground level is a lot cheaper to maintain.), and the cost of supporting the interim use of reliable sources.

The problem is that you are looking at it from an idealistic Scottish perspective. The more practical Irish saying is: If I was going to Cork, I wouldnt start from Dublin. Alas we are, metaphorically, in Dublin. And riding a diplodocus or two.
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Re: How can renewable energy farms provide 24-hour power?
« Reply #26 on: 10/04/2015 15:09:06 »
Quote from: alancalverd on 10/04/2015 09:09:57
This is the 8th consecutive day with wind below 2 GW - your storage system is looking a bit marginal.
I demonstrated with a graph how my plan coped with your challenge but still you nit-pick. [|)]

Quote from: alancalverd on 10/04/2015 09:09:57

However, having addressed the elephant in the room, it is a good time to look at a couple of diplodoci.

Diplodocus 1. Electricity accounts for less than 25% of UK energy consumption. Practically all the rest is direct burning of fossil fuels. So if you replaced all electricity generation with wind, we would still be emitting at least 75% of current carbon dioxide levels, and society would grind to a halt when the oil runs out.
Well what is the real problem? Fossil fuels "running out" or "warming the globe"?

Quote from: alancalverd on 10/04/2015 09:09:57
If you want to run everything on unreliables, you will need at least 4 times as much generating distribution and storage capacity as your current best estimate,
The 25% of energy use for transport would need 2 times as much (more because of rush hours by trains and trams but less because electric motors are more efficient than combustion engines) but the 50% of heating energy doesn't need proportionally more electrical power because we can use the surplus power at windy times for hydrogen generation from power-to-gas and electrical storage heaters using off-peak electricity. Also heat pumps and geothermal heating provide proportionally more heat energy than electrical power consumed.

Quote from: alancalverd on 10/04/2015 09:09:57
plus an unimaginable capital expenditure on electric transport and heating. As that expenditure will be mandatory, it will have to come from government or the windmill builders. Fat chance.
We can imagine and estimate the expenditure but none of it is "mandatory". We could just let the globe warm up.

Quote from: alancalverd on 10/04/2015 09:09:57
Diplodocus 2. We use electricity because it is cheapish and reliable. Given that you will need to install at least 3 times overcapacity (possibly 7 times on my assumptions)
I've recommended nameplate maximum wind power = 5.5 times peak demand.

The figures I gave were very clear - for Scotland 33GW/6GW = 5.5, for UK 290GW/52.5GW = 5.5

I'm not sure where you get "3" or "7" from?

Quote from: alancalverd on 10/04/2015 09:09:57
plus storage facilities in order to approach current levels of reliability, what is the anticipated future unit cost?
I anticipated a total cost in my first post.

Quote from: Scottish Scientist on 08/04/2015 15:26:30
My cost estimate for Scotland was £50 billion for wind turbines and pumped-storage not counting grid infrastructure upgrades.

So say maybe £480 billion for the UK.

The annual government budget for the UK is something over £700 billion so a project of the size of £480 billion or the cost of 40 channel tunnels would clearly take a number of years to afford and to build.

So renewables-only electricity generation is indeed possible but it is not cheap and it is not easy, if my figures are anything like correct.

It all depends on how quickly, over how many years, the country decided to spend those vast amounts of money and how it was funded.  There's no requirement to fund any of it by additions to fuel bills.


Quote from: alancalverd on 10/04/2015 09:09:57
You need to take into account a 10 - 15 year life for outdoor electromechanical equipment, a sensible rate of return on capital, maintenance costs (I usually estimate 50 - 100% of capital cost over 10 years for a guaranteed uptime maintenance contract. Equipment installed indoors at ground level is a lot cheaper to maintain.), and the cost of supporting the interim use of reliable sources.
Well it would have to be built to last because £480 billion extra is not an amount of money which Britain could afford to spend on electricity bills every 10 to 15 years. Maintenance costs would have to be much less than the capital investment otherwise it's not affordable.

Quote from: alancalverd on 10/04/2015 09:09:57
The problem is that you are looking at it from an idealistic Scottish perspective. The more practical Irish saying is: If I was going to Cork, I wouldnt start from Dublin. Alas we are, metaphorically, in Dublin. And riding a diplodocus or two.
Much is favourable in Scotland for renewable energy - the geography is ideal for both wind and pumped-storage - so Scotland could serve as a testing ground for a renewables-only energy strategy, for Britain, Europe and the world to test out solutions.

If we can't afford to do renewables-only in Scotland, chances are it won't be affordable anywhere.

HEY 'APOSTROPHES' ARE ALLOWED AGAIN!  [:)]
« Last Edit: 10/04/2015 16:16:04 by Scottish Scientist »
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Re: How can renewable energy farms provide 24-hour power?
« Reply #27 on: 10/04/2015 17:46:34 »
Quote
This is because 1400GWh is 58.33 GW-days

Fine. But average demand for the last 8 days has been over 30 GW so you needed 240 GW-days to supply it. I don't think a 300% shortfall (and the wind is only just now picking up to 3 GW) is "nitpicking"!

Quote
I've recommended nameplate maximum wind power = 5.5 times peak demand.

The figures I gave were very clear - for Scotland 33GW/6GW = 5.5, for UK 290GW/52.5GW = 5.5

I'm not sure where you get "3" or "7" from?


We're not far apart here. 3 is the absolute minimum required to meet average demand, assuming that all future windfarms have the same average load factor as at present. Thus is unlikely as the best sites are already occupied. You need twice that capacity in order to meet demand whilst you are recharging your storage facilities, hence 6. Your storage facilities must also be capable of meeting peak demand, hence 7. But given the high failure rate of windmills (see below) you will need a continuous build program to replace them all every 10 years or so, so the figure is probably nearer 8 times.     

Quote
Much is favourable in Scotland for renewable energy - the geography is ideal for both wind and pumped-storage - so Scotland could serve as a testing ground for a renewables-only energy strategy, for Britain, Europe and the world to test out solutions.

Perfectly correct and exactly wrong! Scotland is enormously favoured - perfect geography and climate, with very low populaton density. It is a rubbish model for England - flat, prone to long periods of zero wind, high population density - and virtually irrelevant to the rest of the world. Anywhere windier tends to be unpopulated except for the coast of Iceland, where steam comes out of the ground anyway. Anywhere with higher mountains and more rain already has signficant hydroelectricity.

Not much to test, really. You can't change weather or geography, or do much about demand distribution. Physics is well understood. Which just leaves economics:http://www.ref.org.uk/press-releases/281-wearnandntearnhitsnwindnfarmnoutputnandneconomicnlifetime

Quote
The Renewable Energy Foundation [1] today published a new study, The Performance of Wind Farms in the United Kingdom and Denmark,[2] showing that the economic life of onshore wind turbines is between 10 and 15 years, not the 20 to 25 years projected by the wind industry itself, and used for government projections. 

The work has been conducted by one of the UK’s leading energy & environmental economists, Professor Gordon Hughes of the University of Edinburgh[3], and has been anonymously peer-reviewed.  This groundbreaking study applies rigorous statistical analysis to years of actual wind farm performance data from wind farms in both the UK and in Denmark.

The results show that after allowing for variations in wind speed and site characteristics the average load factor of wind farms declines substantially as they get older, probably due to wear and tear. By 10 years of age the contribution of an average UK wind farm to meeting electricity demand has declined by a third. 

This decline in performance means that it is rarely economic to operate wind farms for more than 12 to 15 years.  After this period they must be replaced with new machines, a finding that has profound consequences for investors and government alike. 

Specifically, investors expecting a return on their investment over 20-25 years will be disappointed.  Policymakers expecting wind farms built before 2010 to be contributing towards CO2 targets in 2020 or later must allow for the likelihood that the total investment required to meet these targets will be much larger than previous forecasts have suggested.  As a consequence, the lifetime cost per unit (MWh) of electricity generated by wind power will be considerably higher than official estimates.

Compared with 45-plus years for nuclear and coal plant, this isn't an attractive investment.

There is a solution, but wind isn't it.
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Re: How can renewable energy farms provide 24-hour power?
« Reply #28 on: 10/04/2015 19:41:40 »
Quote from: alancalverd on 10/04/2015 17:46:34
Quote
This is because 1400GWh is 58.33 GW-days

Fine. But average demand for the last 8 days has been over 30 GW so you needed 240 GW-days to supply it. I don't think a 300% shortfall (and the wind is only just now picking up to 3 GW) is "nitpicking"!
It seems nitpicking when you don't acknowledge the graph I posted shows acceptable performance for the data available when I downloaded it which was up to the 9th April.

Quote from: Scottish Scientist on 09/04/2015 11:59:12
Quote from: alancalverd on 09/04/2015 08:23:25
today is the seventh consecutive day with wind power at less than 2GW. In fact the running average is less than 1 GW for the past week.

As I say, I love a challenge and the low wind period just now is such a challenge, so I've run it through my model - normalised for a case study of the UK this time - and here's the results.


Click for full size image - https://scottishscientist.files.wordpress.com/2015/04/windpumpedstorage_april2015.jpg

So there would still be some water left at this time in the 1400 GWh reservoirs with 290 GW installed wind power, but it is running low admittedly, so we'll have to wait to see if the wind can pick up to save the day or whether I will need to rethink my 1400 GWh / 290 GW recommendation.

Quote from: alancalverd on 09/04/2015 08:23:25
I think you - or at least your customers - will find 24 hours' storage rather inadequate, even in a mild spring.
Remember I have tested these the equivalent of these 1400 GWh / 290 GW specifications (normalised for the case study of Scotland) on the spring of 2014 and it worked.

As you can see for this period in early April 2015, the design specifications of 1400 GWh / 290 GW have managed this period of low wind (so far) for longer than 24 hours of low wind.

This is because 1400GWh is 58.33 GW-days but the daily average of power demand is less than the peak demand of 52.5GW. Demand from April 1 to 9 2015 has varied between a minimum of  25649 MW and a maximum of 43069 MW.


Quote from: alancalverd on 10/04/2015 17:46:34
Quote
I've recommended nameplate maximum wind power = 5.5 times peak demand.

The figures I gave were very clear - for Scotland 33GW/6GW = 5.5, for UK 290GW/52.5GW = 5.5

I'm not sure where you get "3" or "7" from?


We're not far apart here.

We're as far apart as Hans Solo and Luke Skywalker.

Quote
Obi-Wan: How long before you can make the jump to light speed?

Han Solo: It'll take a few moments to get the coordinates from the navi-computer.

[the ship begins to rock violently as lasers hit it]

Luke: Are you kidding? At the rate they're gaining...?

Han Solo: Traveling through hyperspace ain't like dusting crops, boy! Without precise calculations we could fly right through a star, or bounce too close to a supernova and that'd end your trip real quick, wouldn't it.

Quote from: alancalverd on 10/04/2015 17:46:34
3 is the absolute minimum required to meet average demand, assuming that all future windfarms have the same average load factor as at present. Thus is unlikely as the best sites are already occupied. You need twice that capacity in order to meet demand whilst you are recharging your storage facilities, hence 6. Your storage facilities must also be capable of meeting peak demand, hence 7. But given the high failure rate of windmills (see below) you will need a continuous build program to replace them all every 10 years or so, so the figure is probably nearer 8 times.

You are "dusting crops" with your hand-waving guess-timates but I've got my "precise calculations" and "co-ordinates from the navi-computer" from my spreadsheet model.


Quote from: alancalverd on 10/04/2015 17:46:34
Quote
Much is favourable in Scotland for renewable energy - the geography is ideal for both wind and pumped-storage - so Scotland could serve as a testing ground for a renewables-only energy strategy, for Britain, Europe and the world to test out solutions.

Perfectly correct and exactly wrong! Scotland is enormously favoured - perfect geography and climate, with very low populaton density. It is a rubbish model for England - flat, prone to long periods of zero wind, high population density - and virtually irrelevant to the rest of the world. Anywhere windier tends to be unpopulated except for the coast of Iceland, where steam comes out of the ground anyway. Anywhere with higher mountains and more rain already has signficant hydroelectricity.

Not much to test, really. You can't change weather or geography, or do much about demand distribution. Physics is well understood. Which just leaves economics:http://www.ref.org.uk/press-releases/281-wearnandntearnhitsnwindnfarmnoutputnandneconomicnlifetime

Scotland is more of a "rubbish model" for somewhere such as Holland where it is even flatter than England. Scotland could still offer pumped-storage hydro facilities for surplus wind power generated in flat parts of Europe like Holland though.

My point was not that Scotland is the same as elsewhere but that all the key components of a renewables-only energy strategy could be developed, perfected and implemented there. It has the geography and it also has at least the beginnings of the engineers and engineering infrastructure required. It's an excellent place to host the engineering side of a renewables-only international effort.

Scotland is not the only such place in the world but the Scottish government has been keen to promote renewables - we have 5GW of wind power installed already - and I'm sure this is an area of industry where Scots would like to co-operate with others throughout the UK and internationally.

Quote from: alancalverd on 10/04/2015 17:46:34

Quote
The Renewable Energy Foundation [1] today published a new study, The Performance of Wind Farms in the United Kingdom and Denmark,[2] showing that the economic life of onshore wind turbines is between 10 and 15 years, not the 20 to 25 years projected by the wind industry itself, and used for government projections. 

The work has been conducted by one of the UK’s leading energy & environmental economists, Professor Gordon Hughes of the University of Edinburgh[3], and has been anonymously peer-reviewed.  This groundbreaking study applies rigorous statistical analysis to years of actual wind farm performance data from wind farms in both the UK and in Denmark.

The results show that after allowing for variations in wind speed and site characteristics the average load factor of wind farms declines substantially as they get older, probably due to wear and tear. By 10 years of age the contribution of an average UK wind farm to meeting electricity demand has declined by a third. 

This decline in performance means that it is rarely economic to operate wind farms for more than 12 to 15 years.  After this period they must be replaced with new machines, a finding that has profound consequences for investors and government alike. 

Specifically, investors expecting a return on their investment over 20-25 years will be disappointed.  Policymakers expecting wind farms built before 2010 to be contributing towards CO2 targets in 2020 or later must allow for the likelihood that the total investment required to meet these targets will be much larger than previous forecasts have suggested.  As a consequence, the lifetime cost per unit (MWh) of electricity generated by wind power will be considerably higher than official estimates.

Compared with 45-plus years for nuclear and coal plant, this isn't an attractive investment.
Not at 10 to 15 years at £1.6 billion per gigawatt, admittedly. Nevertheless, the UK has 12GW already invested in wind turbines so the technology has advantages over the other renewables which the government has been promoting. Wind still looks like the best of the renewables.

Also, it may well be possible to drive costs down. Either new designs for turbines giving more power per pound and longer service-life or mass production techniques to reduce costs per turbine of much the same design.

Considering the size of the investment required, it makes a lot of sense to see what can be done to get costs down.

Quote from: alancalverd on 10/04/2015 17:46:34
There is a solution, but wind isn't it.
Backed-up with pumped-storage, maybe wind is a solution.

I don't think coal or fossil fuels can be made climate-friendly by carbon capture and storage (CCS) because CCS is vulnerable to black-market dumping of carbon dioxide which will defeat the climate change aim.

Nuclear has excellent prospects for portable power. I have a vision of helicopters big enough or nuclear reactors small enough to be flown anywhere in the world to provide power for the initial development of a location. Or a nuclear-powered ground vehicle, producing energy or fuel to power civil engineering machines - rail-track laying, road-building, runway making, port-construction. Enough to get conventional development established somewhere undeveloped, then the portable nuclear moves on to elsewhere in the wilderness where the going is too tough for fast progress because of power shortages.

So I'm all for nuclear where it offers unique advantages. But nuclear for grid power, I'm not convinced has a future though. Too risky - as Fukushima, Chernobyl, Dounreay shows. If you don't need to take the risk of nuclear - and with renewables, we don't - why take the risk?

« Last Edit: 10/04/2015 20:11:44 by Scottish Scientist »
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Re: How can renewable energy farms provide 24-hour power?
« Reply #29 on: 10/04/2015 20:01:40 »
Quote from: alancalverd on 28/08/2013 10:13:03
Excellent technology, with serious economic consequences.

The problem with unreliable energy sources is that if they account for more than about 10% of the maximum grid capacity, they make the entire system uneconomic. If the wind blew at rated speed for 90% of the time, you would need 10% of your reliable sources to be switched off for 90% of the time in order to cover the gaps. This might be tolerable, but idle machines need space and maintenance, so they represent a financial loss (and the wind generally only blows at 10% of rated speed). Above 10% of unreliables, it is difficult  to persuade anyone to invest in conventional plant: big nukes and clean coal take a long time to fire up, small ones are expensive; gas plant costs less to install but is at the mercy of suppliers on the other side of the world; and whilst oil can be stockpiled, it is horrendously expensive to run. The sensible investment is in nuclear and big coal plant, but the prospect of at least 20% overcapacity or underutilisation will not attract shareholders.

In 2014 Spain got 27% of its energy from wind power (21%) and the solar. According to you, nothing over 10% is possible. Spain are increasing this up to 40%.

Coal and nuclear? Are you blooding kidding?

Nuclear is very, very, very heavily subsidised (about 12p per kWh or more in liability insurance).

As for 'clean coal' what drugs are you on? The piles of toxic sludge that are the end product of burning coal are the lie to that, and there's the huge CO2 pollution. You'd have to be a complete idiot to build new coal power stations. Natural gas is much better, but even that...

Quote
So rather than impose levies on conventional power in order to subsidise unreliables, government should require windfarmers and the like to subsidise conventional standby plant, or require them to install at least 5 days' storage capacity at rated power, and insist that the store is full before allowing them to supply the grid directly.

Um. No.

The way it actually works is that the electricity gets a 'spot price' on the electricity market, and this determines what the electricity is sold at. In some grids, the price of electricity can actually go negative over short periods. The market mostly sorts itself out, people don't install generators if they don't think they will make money; and note that the subsidies on wind are very small right now; pennies per kWh.

Quote from: syhprum on 28/08/2013 13:18:13
But look how terribly dangerous nuclear power is probably as many as 100 people have died as a result of nuclear mishaps since 1940

It's not the deaths it's the economic disruption. Note that we haven't had the worst possible nuclear accident. For example with Fukushima, if the wind had been different, it would have dumped nuclear fallout over Tokyo. There was a possibility that they would have had to evacuate Tokyo...

Try to imagine what that would have been like. My brain is too small to imagine it, and I think yours is too.
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Offline alancalverd

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Re: How can renewable energy farms provide 24-hour power?
« Reply #30 on: 10/04/2015 20:40:41 »
Quote from: Scottish Scientist on 10/04/2015 19:41:40
Quote from: alancalverd on 10/04/2015 17:46:34
Quote
This is because 1400GWh is 58.33 GW-days

Fine. But average demand for the last 8 days has been over 30 GW so you needed 240 GW-days to supply it. I don't think a 300% shortfall (and the wind is only just now picking up to 3 GW) is "nitpicking"!
It seems nitpicking when you don't acknowledge the graph I posted shows acceptable performance for the data available when I downloaded it which was up to the 9th April.

Your graph appears to show 60 GW of wind power on 7 April. Gridwatch put the figure at about 1.5 GW. Does a discrepancy of 4000% count as nitpicking?


Quote
Not at 10 to 15 years at £1.6 billion per gigawatt, admittedly. Nevertheless, the UK has 12GW already invested in wind turbines so the technology has advantages over the other renewables which the government has been promoting. Wind still looks like the best of the renewables.

As long as I have to subsidise your product when I use it, pay an additional subsidy when it is not required, and fire up a coal station when the wind doesn't blow, wind power is one hell of a good investment. But if you eliminate the crooks politicians, insist on adequate storage and grid capacity, and leave it to the market, it isn't.

The fact that the government has been promoting anything is no measure of its rationality. There are three reasons why a politician does anything: because the EU tells him to, because it will improve his chances of re-election, or because his brother-in-law will make a profit.

Quote
We can imagine and estimate the expenditure but none of it is "mandatory". We could just let the globe warm up.

It probably will anyway. Massive climate change predates homo sapiens, and it was warmer 500 years ago than now. Or maybe it will cool down. Nothing we can do to prevent it, but we could spend a bit of time and effort mitigating its effect, which will be disastrous either way. Chucking money at windmill manufacturers won't prevent mass migration as world agriculture fails to meet demand.
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Re: How can renewable energy farms provide 24-hour power?
« Reply #31 on: 10/04/2015 22:18:18 »
Quote from: alancalverd on 10/04/2015 20:40:41
Quote from: Scottish Scientist on 10/04/2015 19:41:40
Quote from: alancalverd on 10/04/2015 17:46:34
Quote
This is because 1400GWh is 58.33 GW-days

Fine. But average demand for the last 8 days has been over 30 GW so you needed 240 GW-days to supply it. I don't think a 300% shortfall (and the wind is only just now picking up to 3 GW) is "nitpicking"!
It seems nitpicking when you don't acknowledge the graph I posted shows acceptable performance for the data available when I downloaded it which was up to the 9th April.

Your graph appears to show 60 GW of wind power on 7 April.
My graph is the result from a computer simulation of what wind power the UK would generate if the UK had installed 290GW of maximum wind power rather than just the 12GW we have installed just now.

So the grey line plots gridwatch data for wind power multiplied by a normalisation factor to indicate what wind power would have been produced had we 290 GW's worth of wind turbines installed. Understand?

Imagine 7 April is Groundhog Day but what Phil Connors (Bill Murray) does different this time is he installs 290 GW of wind turbines and 1400 GWh of pumped-storage hydro.


Quote from: alancalverd on 10/04/2015 20:40:41
Gridwatch put the figure at about 1.5 GW.
Well I told you to be aware about Gridwatch wind power data. Remember?

Quote from: Scottish Scientist on 09/04/2015 11:59:12
Quote from: alancalverd on 09/04/2015 08:23:25
Quote
You know Alan, I love a challenge. I really do. If you can point to the data of a very low wind spell in the UK from Gridwatch, I'd be delighted to test out my model on it.

As you say, we have 12 GW installed windpower in the UK.
Yes.

Quote from: alancalverd on 09/04/2015 08:23:25
According to Gridwatch,
Be aware that Gridwatch data for wind power is not what is served from the full 12 GW installed in the UK, but for only just over 50%. So Gridwatch's maximum wind power data reading in 2014 was only 6835 MW on 2014-12-09 19:50:02.

To check this, visit the Gridwatch website http://www.gridwatch.templar.co.uk/
and hover your mouse above the wind power dial and a context pop-up text bubble appears which says ..
Quote
Wind: This is the total contributed by metered wind farms. Wind power contributes another about 50% from embedded (or unmetered) wind turbines that shows only as a drop in demand.

Which means a Gridwatch wind data item of "about 1.5 GW" corresponds to a real UK wind power generation of something a bit less than 3 GW.


Quote from: alancalverd on 10/04/2015 20:40:41
Does a discrepancy of 4000% count as nitpicking?
The exact normalisation factor used in the simulation is 4243%. That is worked out as 290000 / 6835.

290000 MW is the 290 GW maximum wind power installed being modelled and 6835 MW is the maximum wind power data item from Gridwatch wind power on 2014-12-09 19:50:02

So the model plots 42 times the wind power data Gridwatch records but only 290/12 or 24 times the actual wind power currently installed.

So you were only nitpicking about the days plotted, when there is no way I could have plotted data that was not available at the time.

It seems you have not before now begun to examine what values are being plotted.

So maybe less nitpicking on the days plotted and more attention to the detail of what is being plotted might be appropriate.

Quote from: alancalverd on 10/04/2015 20:40:41
Quote
Not at 10 to 15 years at £1.6 billion per gigawatt, admittedly. Nevertheless, the UK has 12GW already invested in wind turbines so the technology has advantages over the other renewables which the government has been promoting. Wind still looks like the best of the renewables.

As long as I have to subsidise your product when I use it, pay an additional subsidy when it is not required, and fire up a coal station when the wind doesn't blow, wind power is one hell of a good investment. But if you eliminate the crooks politicians, insist on adequate storage and grid capacity, and leave it to the market, it isn't.
Well the energy market was never going to find its way to renewable energy on its own. It needed incentives. Either that or nationalisation.

Quote from: alancalverd on 10/04/2015 20:40:41
The fact that the government has been promoting anything is no measure of its rationality. There are three reasons why a politician does anything: because the EU tells him to, because it will improve his chances of re-election, or because his brother-in-law will make a profit.
And the greatest of these is "because it will improve his chances of re-election"  [^]

Quote from: alancalverd on 10/04/2015 20:40:41
Quote
We can imagine and estimate the expenditure but none of it is "mandatory". We could just let the globe warm up.

It probably will anyway. Massive climate change predates homo sapiens, and it was warmer 500 years ago than now. Or maybe it will cool down. Nothing we can do to prevent it, but we could spend a bit of time and effort mitigating its effect, which will be disastrous either way.
Disastrous which "either way"? Warmer or colder? Preventing or not preventing? Mitigating or not mitigating?

It seems to me if we can prevent it getting a lot warmer that's likely to prevent a disaster.

If we can't prevent it getting a lot warmer, it seems to me mitigating it - by say moving to settle the cooler polar regions, building sea walls to keep out rising sea levels, growing crops on floating man-made islands towed to where it is cooler, putting up orbiting sun-reflectors - that could all help to prevent a disaster.

Quote from: alancalverd on 10/04/2015 20:40:41
Chucking money at windmill manufacturers won't prevent mass migration as world agriculture fails to meet demand.
Well it may just help a lot with that too.
« Last Edit: 10/04/2015 22:22:18 by Scottish Scientist »
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Offline alancalverd

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Re: How can renewable energy farms provide 24-hour power?
« Reply #32 on: 11/04/2015 00:40:01 »
Quote
Disastrous which "either way"? Warmer or colder?

Yes.

A bit colder and crops fail in Russia, western Europe and North America. A bit warmer and crops fail in southern Asia. Either way you will be looking at mass starvation or mass migration. We may be lucky as the warming seems to have slowed down a bit, but it hasn't reached a historic maximum yet. Unfortunately the human population has, and continues to rise, so life is becoming more marginal each day.

You might try to increase crop yields with artificial fertilisers, but it's already the case that about 20% of the mass of humans is derived from the Haber-Bosch process, which consumes vast quantities of fossil fuel (about 5% of all natural gas, currently) and ultimately damages the environment through nitrate runoff. Even if we ignore those elephants, a small change in rainfall distribution will be disastrous.

In summary: wind-generated electricity on a large scale creates more problems than it solves and is not affordable as a significant replacement for conventional generation; electricity is in any case not the key energy source for sustaining human life or lifestyle; and a climate-led disaster is pretty well inevitable. 

One question intrigues me: the "unmetered" wind power contribution. I can't imagine anyone giving away expensively-generated electricity, so my guess is that the unmetered capacity is individual windmills supplying fully-off-grid installations. Thus whilst they might be said to be reducing (or rather, eliminating) demand, you can't factor them against the actual metered demand on the grid.  I'd appreciate some elucidation here. 
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Re: How can renewable energy farms provide 24-hour power?
« Reply #33 on: 11/04/2015 00:44:36 »
Quote from: wolfekeeper on 10/04/2015 23:26:02
It's perfectly possible to power an electric car your normal mileage using the electricity from a domestic roof PV. You need just 5kWh generation per day to get the average car mileage.

That's great if you work night shifts. Unfortunately most people use their cars during daylight. I guess you could have two cars, but as it takes as much energy to make a conventional car as it uses during its lifetime, and rather more to make an electric car, you're still screwed by the laws of physics.
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Re: How can renewable energy farms provide 24-hour power?
« Reply #34 on: 11/04/2015 01:48:28 »
Not on today's grid it doesn't. Solar panels mean that the fossil fuel production goes down during the day, and the car pulls it back up at night. So the net carbon footprint is zero, or negative, even if you're not putting the electricity directly into the car.

And suitable pricing would help. You should be able to be charging your car with the electricity you're generating, even if you're not at home. It's all the same grid. There's no reason that couldn't be sorted out.
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Re: How can renewable energy farms provide 24-hour power?
« Reply #35 on: 11/04/2015 02:08:09 »
Quote from: alancalverd on 11/04/2015 00:40:01
Quote
Disastrous which "either way"? Warmer or colder?

Yes.

A bit colder and crops fail in Russia, western Europe and North America. A bit warmer and crops fail in southern Asia. Either way you will be looking at mass starvation or mass migration. We may be lucky as the warming seems to have slowed down a bit, but it hasn't reached a historic maximum yet.
Even at our unluckiest, global warming couldn't speed up faster than the speed of modern civilisation to focus on the warming, slow it down or find another solution to any problems arising.

I wouldn't describe mass migration as necessarily being a "disaster" per se. One could describe the movement of Homo Sapiens out of Africa as a mass migration that happened over 200,000 years. Out-of-Africa was not exactly a disaster, except perhaps for the Neanderthals and maybe the previous top predators who had to make way for man.

The colonisation of the Americas was a mass migration. Again not a disaster, except perhaps for indigenous civilisations, such as they were.

You say "mass migration" like it is a bad thing. It doesn't have to be.

Quote from: alancalverd on 11/04/2015 00:40:01
Unfortunately the human population has, and continues to rise, so life is becoming more marginal each day.
Now human population is something which can rise and fall at an astonishing rate compared to global temperature changes. However population rise can also be a solution, if the populations are well led and productive.

Quote from: alancalverd on 11/04/2015 00:40:01
You might try to increase crop yields with artificial fertilisers, but it's already the case that about 20% of the mass of humans is derived from the Haber-Bosch process, which consumes vast quantities of fossil fuel (about 5% of all natural gas, currently) and ultimately damages the environment through nitrate runoff.
All such bridges have been crossed when we got to them. So shall it be.


Quote from: alancalverd on 11/04/2015 00:40:01
Even if we ignore those elephants, a small change in rainfall distribution will be disastrous.
I can see you are a rainfall gauge "half-empty" kind of guy.   [8D]

Quote from: alancalverd on 11/04/2015 00:40:01
In summary: wind-generated electricity on a large scale creates more problems than it solves and is not affordable as a significant replacement for conventional generation; electricity is in any case not the key energy source for sustaining human life or lifestyle; and a climate-led disaster is pretty well inevitable.
Well the affordability of £480 billion for the UK - or proportional sums for other countries - is questionable certainly. It would be wise not to put all our eggs in that basket until such time as the figures look more affordable. Nevertheless putting some eggs in that basket would be wise.

Quote from: alancalverd on 11/04/2015 00:40:01
One question intrigues me: the "unmetered" wind power contribution. I can't imagine anyone giving away expensively-generated electricity, so my guess is that the unmetered capacity is individual windmills supplying fully-off-grid installations. Thus whilst they might be said to be reducing (or rather, eliminating) demand, you can't factor them against the actual metered demand on the grid.  I'd appreciate some elucidation here.
I didn't factor in non-metered demand into my calculations. That was ignored or discounted as irrelevant. The system I designed and modelled was to supply the metered demand only and it does that, perfectly so far.
« Last Edit: 11/04/2015 02:14:03 by Scottish Scientist »
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Re: How can renewable energy farms provide 24-hour power?
« Reply #36 on: 11/04/2015 02:21:25 »
A lot of the 'unmetered' wind and (more so) solar is actually on the grid, and metered, but there's no real-time monitoring of them, so the graphs don't include them. Basically the individual installations are too small.

Nevertheless they do subtly appear on the graphs, but as a reduction in demand. The national grid do model them by using met-office data.
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Re: How can renewable energy farms provide 24-hour power?
« Reply #37 on: 11/04/2015 09:42:12 »
Quote from: Scottish Scientist on 11/04/2015 02:08:09

Even at our unluckiest, global warming couldn't speed up faster than the speed of modern civilisation to focus on the warming, slow it down or find another solution to any problems arising.

20 years after the Kyoto Protocol, nothing has been done. In fact, if the warmists are to be believed, things are getting worse. I don't share your faith in human altruism. 

Quote
I wouldn't describe mass migration as necessarily being a "disaster" per se. One could describe the movement of Homo Sapiens out of Africa as a mass migration that happened over 200,000 years. Out-of-Africa was not exactly a disaster, except perhaps for the Neanderthals and maybe the previous top predators who had to make way for man.
The gradual dispersal of a few humans into unoccupied hunting grounds cannot be compared with the movement of 150,000,000 Bangladeshis when the sea level rises and the crops fail for 3 consecutive years.

Quote
The colonisation of the Americas was a mass migration. Again not a disaster, except perhaps for indigenous civilisations, such as they were.
Hardly mass migration. The population of Tennessee, for instance, has grown "internally" by a factor of 200 since independence, and of the entire USA by a factor of 100 in just over 200 years. And as with the African diaspora, the spread has been onto largely unpopulated but very fertile land. There's not a lot left.

Quote
You say "mass migration" like it is a bad thing. It doesn't have to be.
Your peaceful solution to a 5 cm sea level rise in Bangladesh would be welcome.


Quote
Now human population is something which can rise and fall at an astonishing rate compared to global temperature changes. However population rise can also be a solution, if the populations are well led and productive.
You are halfway to the solution. We could live very well and entirely sustainably with about one tenth of the present population. If we reproduce at half the replacement level, we would reach that state in 100 years at no cost - in fact a considerable saving of effort and money. I shudder at the idea of "well led": Great Leaders like Stalin, Mao, Hitler and Thatcher were a disaster.

Quote
Quote from: alancalverd on 11/04/2015 00:40:01
You might try to increase crop yields with artificial fertilisers, but it's already the case that about 20% of the mass of humans is derived from the Haber-Bosch process, which consumes vast quantities of fossil fuel (about 5% of all natural gas, currently) and ultimately damages the environment through nitrate runoff.
All such bridges have been crossed when we got to them. So shall it be.
What an appalling strategy! Everyone involved in such activities, from Caesar to Montgomery, regarded the planning of bridges and crossings to be absolutely essential to progress. There's an old saw about "the skilled pilot uses his skill to foresee and avoid situations that will place demands on his skill".


Quote
Quote from: alancalverd on 11/04/2015 00:40:01
Even if we ignore those elephants, a small change in rainfall distribution will be disastrous.
I can see you are a rainfall gauge "half-empty" kind of guy.   [8D]
Well spotted. Actually I'm a pilot who notices "tanks half empty" before the fires go out.

Quote
I didn't factor in non-metered demand into my calculations. That was ignored or discounted as irrelevant. The system I designed and modelled was to supply the metered demand only and it does that, perfectly so far.

Hold on there, pardner! You insist that present wind supply is twice what Gridwatch displays, but present demand is only the metered demand. You can't have it both ways!
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Re: How can renewable energy farms provide 24-hour power?
« Reply #38 on: 11/04/2015 11:30:04 »
Quote from: alancalverd on 11/04/2015 09:42:12
Quote from: Scottish Scientist on 11/04/2015 02:08:09

Even at our unluckiest, global warming couldn't speed up faster than the speed of modern civilisation to focus on the warming, slow it down or find another solution to any problems arising.

20 years after the Kyoto Protocol, nothing has been done. In fact, if the warmists are to be believed, things are getting worse. I don't share your faith in human altruism.
Civilisation has accomplished a lot in 20 years, including installation of renewable energy electricity generators. You, I and the warmists are 20 years older. For us as individuals things can always get worse, of course.

Quote from: alancalverd on 11/04/2015 09:42:12
Quote
I wouldn't describe mass migration as necessarily being a "disaster" per se. One could describe the movement of Homo Sapiens out of Africa as a mass migration that happened over 200,000 years. Out-of-Africa was not exactly a disaster, except perhaps for the Neanderthals and maybe the previous top predators who had to make way for man.
The gradual dispersal of a few humans into unoccupied hunting grounds cannot be compared with the movement of 150,000,000 Bangladeshis when the sea level rises and the crops fail for 3 consecutive years.

Quote
The colonisation of the Americas was a mass migration. Again not a disaster, except perhaps for indigenous civilisations, such as they were.
Hardly mass migration. The population of Tennessee, for instance, has grown "internally" by a factor of 200 since independence, and of the entire USA by a factor of 100 in just over 200 years. And as with the African diaspora, the spread has been onto largely unpopulated but very fertile land. There's not a lot left.
There's a lot of infertile land left world-wide to be made fertile by appropriate civil engineering works. There's also a lot of ocean left to be floated upon.

Quote from: alancalverd on 11/04/2015 09:42:12
Quote
You say "mass migration" like it is a bad thing. It doesn't have to be.
Your peaceful solution to a 5 cm sea level rise in Bangladesh would be welcome.
Raise the land by 5cm. Raise the sea walls by 5cm. If my first guess is not appropriate there will be plenty of time for the people of Bangladesh to come up with better solutions.

Quote from: alancalverd on 11/04/2015 09:42:12
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Now human population is something which can rise and fall at an astonishing rate compared to global temperature changes. However population rise can also be a solution, if the populations are well led and productive.
You are halfway to the solution. We could live very well and entirely sustainably with about one tenth of the present population. If we reproduce at half the replacement level, we would reach that state in 100 years at no cost - in fact a considerable saving of effort and money.
There's no need to seek to reduce the population. More people means more effort and money is available.

Quote from: alancalverd on 11/04/2015 09:42:12
I shudder at the idea of "well led": Great Leaders like Stalin, Mao, Hitler and Thatcher were a disaster.
The bad leaders make my point that the quality of leadership makes a difference.

Quote from: alancalverd on 11/04/2015 09:42:12
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Quote from: alancalverd on 11/04/2015 00:40:01
You might try to increase crop yields with artificial fertilisers, but it's already the case that about 20% of the mass of humans is derived from the Haber-Bosch process, which consumes vast quantities of fossil fuel (about 5% of all natural gas, currently) and ultimately damages the environment through nitrate runoff.
All such bridges have been crossed when we got to them. So shall it be.
What an appalling strategy! Everyone involved in such activities, from Caesar to Montgomery, regarded the planning of bridges and crossings to be absolutely essential to progress. There's an old saw about "the skilled pilot uses his skill to foresee and avoid situations that will place demands on his skill".
Well I've managed to cross my own bridges perfectly well thank you. I don't claim to cross everyone else's bridges for them but trust them to do so for themselves but offer my help if needed.

Quote from: alancalverd on 11/04/2015 09:42:12
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Quote from: alancalverd on 11/04/2015 00:40:01
Even if we ignore those elephants, a small change in rainfall distribution will be disastrous.
I can see you are a rainfall gauge "half-empty" kind of guy.   [8D]
Well spotted. Actually I'm a pilot who notices "tanks half empty" before the fires go out.
So you fly a fire-fighting airplane, do you? I always think there is more sense in dry lands subject to fires in allowing or insisting that people clear fire-breaks around their houses and that authorities do the same for roads so as to keep people safe enough but otherwise just let forests and scrub land burn. I'd rather employ fire-fighters in helicopters to go rescue people in danger than to employ them putting out forest, bush etc. fires.

Quote from: alancalverd on 11/04/2015 09:42:12
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I didn't factor in non-metered demand into my calculations. That was ignored or discounted as irrelevant. The system I designed and modelled was to supply the metered demand only and it does that, perfectly so far.

Hold on there, pardner! You insist that present wind supply is twice what Gridwatch displays, but present demand is only the metered demand. You can't have it both ways!
I've not claimed either the unmetered demand or unmetered wind is "not present". I've simply ignored both unmetered demand and unmetered wind power as not relevant to my calculations, my recommended solution or the success of my solution. I'd be recommending 290GW even if unmetered demand and unmetered wind was 1000 times what it is, even if it was all the rest of the demand and the wind power in the world, even if it was demand and wind power in strange new worlds, new civilisations, to which we have not yet boldly gone.

My plan is to meet the metered UK demand with 290GW and 1400GWh and so far, so good.
« Last Edit: 11/04/2015 11:56:08 by Scottish Scientist »
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Offline wolfekeeper

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Re: How can renewable energy farms provide 24-hour power?
« Reply #39 on: 11/04/2015 15:32:11 »
The only thing I disagree with in the model is that you're assuming only wind and pumped storage.

In the real world we have solar coming up. It's running behind wind because it's more expensive than it, and much more expensive than burning dinosaurs... but it's starting to be cheaper than metered electricity from the grid. When that happens the price of the metered electricity from the grid will start to go up; more of the electricity will be peaking electricity. This will push installation of solar ever harder, because it's cheaper to the end user, and the grid will get greener.

Also, wind and solar are anti-correlated.

During the summer, the wind is relatively low, but solar goes up. Vice versa in the winter.

And then there's electric cars. Electric cars are a drop in the bucket right now. But the lifetime cost of electric cars is becoming cheaper than petrol cars. We're more or less at the cusp. When we cross the cusp a LOT of people are going to start buying. Sure, they're not good for everyone, but 99% of most people's journeys can be done with them (some people-notably sales people-need hybrids or diesels or other cars). But the vast majority of other people are better off with electric cars. So we're probably going to suddenly see a jump; large percentages of new cars will electric.

I mean, right now, there's about 2 million new cars sold each year in the UK. If even half a million electric cars were sold, after two years, there would be one million cars. If they were connected to the grid through inverters, then they could potentially supply the entire electricity demand for about half an hour (not that they would, but the point is that it's a *substantial* resource.)

So, electric cars; the pumped storage stuff may not be needed.

The fundamental point is that the more you add different types of sources and other storage to the mix, the more the variations even out. So the full 290 GW may not be needed; that gives on average maybe 70 GW or a little less, but to the extent other sources provide power, this can be reduced.
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