[David Cooper]

You think you could get planning permission for that massive salt-water tank? There are better technologies on the way which will wipe out the point of it before it could be built.

[alancalverd]

The scale of this 64 GW dam project can best be appreciated by comparison with the Hoover Dam with a peak output of 1.4GW, and Drax power station (4GW). The largest hydroelectric station in the UK is 0.3GW at present. Admittedly these are fairly historic structures, so a fair comparison would be with the 22 GW Three Gorges Dam

......the dam flooded archaeological and cultural sites and displaced some 1.3 million people, and is causing significant ecological changes, including an increased risk of landslides. The dam has been a controversial topic both domestically and abroad.

except that both Hoover and Three Gorges are freshwater systems. Having overcome the minor technical problem of pumping seawater back and forth, raised enough money to build a power station three times larger than any other on the planet, and installed a distribution system to carry the entire national demand to and from one station instead of 600 with sufficient redundancy, you may find just the teensiest hint of concern from the occasional treehugger!

I think it is an inspiring project, which should be started immediately and funded entirely by the windpower industry. As the Hoover Dam was completed in 5 years and the Three Gorges in 12, it should be possible to complete this project before wind generation exceeds 20% of grid capacity - the point at which grid stability would be seriously compromised. The only pity is that it is in the wrong place:

Because of the power loss associated with this north to south flow, the effectiveness and efficiency of new generation capacity is significantly affected by its location. For example new generating capacity on the south coast has about 12% greater effectiveness due to reduced transmission system power losses compared to new generating capacity in north England, and about 20% greater effectiveness than northern Scotland.

but you can't have everything!

[wolfekeeper]

Mere scale is virtually never a reason not to do something. You should look at stuff like cost per person, and the timescale over which it would be built instead.

[alancalverd]

Scale is important because this project requires capital input. There is obviously no physical reason why it can't be done but the practicality is that you need enough money up front to start the work, with a sufficient promise that it will be funded to completion. Failing that, a project will run into the sand as lack of continuing funding means delay, which increases costs and makes further funding less attractive.   

Whilst Scottish independence remains a serious possibility, it won't be funded by the UK government, so the money has to be raised either by private investors or by taxing the Scots for long enough to build up the required capital reserve (and not spending it on something else, which politicians are bound to do).   

So, let's have some cost estimates, please!

[Scottish Scientist]

I’ve updated my post to include more detailed estimates for the reservoir volume, maximum flow rate, energy storage and power capacity.

The volume of water impounded by the dam - about 4.4 billion metres-cubed of water.

The maximum potential energy which could be stored – about 6800 Gigawatt-hours – or 280 Gigawatt-days.

To fill or empty the reservoir in a day would require a flow rate of  51,000 metres-cubed per second, the equivalent of the discharge flow from the Congo River, only surpassed by the Amazon!

When nearly empty and powering only the lower turbines by the sea, then about 132 GW could be produced. When nearly full and the upper turbines at the base of the dam fully powered too then about 264 GW could be produced.

I’ve also used the Manning formula to estimate a canal size to cope with the maximum flow rate.

Canal

The empirical Manning formula relates the properties, such as volume rate, gradient, velocity and depth of a one-directional steady-state water flow in a canal.



Click to view a larger image - https://scottishscientist.files.wordpress.com/2015/04/manning_power_canal_200.jpg

For 2-way flow, the canal must support the gradient in both directions and contain the stationary water at a height to allow for efficient starting and stopping of the flow.



Click to view a larger image - https://scottishscientist.files.wordpress.com/2015/04/2-way_power_canal1.jpg

The “2-way Power Canal” diagram charts from a spreadsheet model for a 51,000 m³/s flow how the width of the water surface in a 45-degree V-shaped canal varies with the designed maximum flow velocity. The lines graphed are

• Moving width – from simple geometry, for a constant volume flow, the faster the flow velocity, the narrower the water surface width

• Static width – the width of the surface of the stationary water with enough height and gravitational potential energy to convert to the kinetic energy of the flow velocity

• 30km 2-way wider by – using the Manning formula, the hydraulic slope can be calculated and therefore how much higher and deeper the water must begin at one end of a 30km long canal to have sufficient depth at the end of the canal and therefore by how much wider the canal must be

• Canal width – adding the 30km-2-way-wider-by value to the static-width determines the maximum design width of the water surface.

The equation thus derived,

y = 2 √ ( 51000/x) + 0.1529 x² + x^8/3/40

where y is the maximum surface water width in the canal and x is the designed maximum flow velocity

predicts a minimum value for the canal width of about 170 metres (plus whatever additional above the waterline freeboard width is added to complete the design of the canal) at a design maximum flow velocity between 10 and 11 metres per second.

Guinness World Records states that the widest canal in the world is the Cape Cod Canal which is “only” 165 metres wide.

So the canal, too, would be the biggest ever!

You think you could get planning permission for that massive salt-water tank?

Well the SSE got planning permission for their plans for a pumped-storage hydro-scheme at Coire Glas.

BBC: "Scottish government approves £800m Lochaber hydro scheme" - http://www.bbc.co.uk/news/uk-scotland-highlands-islands-25365786

Admittedly, the SSE plan is only for a 30GWh reservoir and mine is some 226 times bigger.

There are better technologies on the way which will wipe out the point of it before it could be built.

Well the "long-life" electrical battery has been such a favourite topic for marketing hyperbole for so many decades that scientists are naturally sceptical of any such new claims.

The scale of this 64 GW dam project

I've increased the estimate for the storage capacity up from "200 GW-days or more" to "280 GW-days", so even assuming David MacKay's very conservative requirements for 5-days of average power that estimate goes up to 280/5 x 1.6 = 90 GW.

can best be appreciated by comparison with the Hoover Dam with a peak output of 1.4GW, and Drax power station (4GW). The largest hydroelectric station in the UK is 0.3GW at present. Admittedly these are fairly historic structures, so a fair comparison would be with the 22 GW Three Gorges Dam

......the dam flooded archaeological and cultural sites and displaced some 1.3 million people, and is causing significant ecological changes, including an increased risk of landslides. The dam has been a controversial topic both domestically and abroad.

The population density of the Highlands of Scotland is 9 people /km². The scheme could be easily contained within 4 squares each of 10km x 10 km. So tops only 400km² x 9 = 3600 people might be displaced (with generous compensation I trust).

except that both Hoover and Three Gorges are freshwater systems. Having overcome the minor technical problem of pumping seawater back and forth,

The Okinawa pumped-storage hydro scheme uses the sea as a lower reservoir.
http://en.wikipedia.org/wiki/Okinawa_Yanbaru_Seawater_Pumped_Storage_Power_Station

raised enough money to build a power station three times larger than any other on the planet,

Even the SSE has not raised the £800 million for their 226 times smaller scheme, so the 226 x £0.8 billion = £180 billion for this scheme is a big ask.

and installed a distribution system to carry the entire national demand to and from one station instead of 600 with sufficient redundancy,

It all adds to the cost, for sure.

you may find just the teensiest hint of concern from the occasional treehugger!

We can easily plant more trees than we have to uproot for this scheme.

I think it is an inspiring project, which should be started immediately and funded entirely by the windpower industry.

No for this, I was thinking some of the European Central Bank quantitative easing money would come in handy.
http://www.bbc.co.uk/news/business-30933515
The ECB has only created 60 billion Euros because, after all, governments don't tend to trust bankers all that much these days but for a sound investment like this, with overwhelming benefits for Europe's renewable energy goals, perhaps the ECB can be persuaded to chip-in a good deal more than 60 billion Euros. Then of course the UK can chip-in with some Q.E. or deficit-spending likewise.

It's a big ask but it is worth it.

As the Hoover Dam was completed in 5 years and the Three Gorges in 12, it should be possible to complete this project before wind generation exceeds 20% of grid capacity - the point at which grid stability would be seriously compromised. The only pity is that it is in the wrong place:

Well this scheme's full power output from 130 GW up to 230 GW of power available is 20% of 650 GW to 1150 GW or 20% of the entire generation capacity of Europe.
http://www.eia.gov/cfapps/ipdbproject/IEDIndex3.cfm?tid=2&pid=2&aid=7

Because of the power loss associated with this north to south flow, the effectiveness and efficiency of new generation capacity is significantly affected by its location. For example new generating capacity on the south coast has about 12% greater effectiveness due to reduced transmission system power losses compared to new generating capacity in north England, and about 20% greater effectiveness than northern Scotland.

but you can't have everything!

Direct current is more efficient for long distance power transmission.
http://en.wikipedia.org/wiki/High-voltage_direct_current

Mere scale is virtually never a reason not to do something. You should look at stuff like cost per person, and the timescale over which it would be built instead.

Agreed.

Scale is important because this project requires capital input. There is obviously no physical reason why it can't be done but the practicality is that you need enough money up front to start the work, with a sufficient promise that it will be funded to completion. Failing that, a project will run into the sand as lack of continuing funding means delay, which increases costs and makes further funding less attractive.   

Whilst Scottish independence remains a serious possibility, it won't be funded by the UK government, so the money has to be raised either by private investors or by taxing the Scots for long enough to build up the required capital reserve (and not spending it on something else, which politicians are bound to do).   

I think the way to build this is not all at once but first to build part of the sea-side scheme, using a length of canal as an upper reservoir.

Get a system working for Scottish 2020 renewables-only needs then once the team which has done that has a working scheme in place, hopefully the investment to complete the rest of the sea-side scheme and the reservoir and dam-base pumps would become available.

That way at least we'd have working pumped-storage to show for any investment if the money ran out before final completion.

So, let's have some cost estimates, please!

8 GW / 8.5 GW-days - £5.4 billion (Scottish needs demonstrator project, using about 20km of canal as the upper reservoir)
264 GW / 280 GW-days- £180 billion

[David Cooper]

There are better technologies on the way which will wipe out the point of it before it could be built.

Well the "long-life" electrical battery has been such a favourite topic for marketing hyperbole for so many decades that scientists are naturally sceptical of any such new claims.

I was thinking about two things: nuclear fusion power stations, and battery storage optimised not for power to weight ratio but for low cost bulk storage (there are promising noises coming from people working on that). Both of these will be in place before you can build your monster.

What is certain is that your giant fish tank would meet with enormous opposition for a variety of obvious reasons. You're talking about a dam 300m high and 2km long - an earthquake of 6 on the Richter scale is not an impossibility in that location, so I wouldn't want to live downhill from there.

[alancalverd]

The production of concrete generates 410 kg of CO₂ per m³.

A dam is roughly triangular in section with base width equal to its height, so we are looking at a carbon footprint of 37 million tonnes of carbon dioxide for the dam, plus probably twice as much to line the canal. plus whatever it takes to get the concrete to site. I guess at least 150 megatonnes. How much wind energy is required to offset this?

Remember that this project doesn't generate any energy, it merely stores energy generated elswhwere, so there's no "carbon offset" involved.

Nuclear power has the lowest carbon footprint of all energy sources, at about 4 gram per kWh so you would need 37,500 GWh of additional free wind energy to repay the carbon cost of building the project. Except that wind actually has a higher carbon footprint than nuclear, so if you wanted to reduce the overall carbon emission of the electricity grid you would do better to replace all the fossil plant with nuclear: no storage problem, no additional land requirement, and no additional transmission grid capacity.

But the SNP is pledged to a non-nuclear Scotland!

[chiralSPO]

I agree that nuclear power is an excellent, low carbon energy source that should be taken better advantage of. However, that doesn't get you completely away from the energy storage problem. Nuclear plants have a very constant output, that can only be modulated a little bit, and quite slowly (as far as I know). While this can be used to provide a large portion of the base load, it is ill-adapted to the variability in consumer demand for electricity. Energy storage technology is still required for peak shaving and peak shifting, if you don't want to have some gas- or coal-fired powerplants that get cycled on and off as needed...

[David Cooper]

We could get rid of a lot of the sudden peaks in energy demand by getting rid of soap operas.

[alancalverd]

There is certainly a place for pumped energy storage in an all-nuclear system, but as the ramp-up time for a nuke is a matter of minutes (the trick is never to shut the reactor down completely, and baseload is about half peak in the UK), you don't need to store the entire grid demand for 5 days, just half the demand for an hour or two. This was the philosophy behind Dinorwig, and it works very well.   

As I recall, the largest peak demand was during the Queen's coronation. as the procession left the Abbey, the entire nation switched the kettle on and went for a pee.

[wolfekeeper]

Nuclear is a non starter; renewables are growing far faster and that's not changing any time soon.

Although nuclear reactors can and are built to load follow, running a nuclear reactor at partial power makes it even less economic; the cost of the electricity is inversely proportional to its production.

Indeed that's why Dinorwig was built, it looked like they would need a whole bunch of pumped storage because the plan was to produce lots of nuclear power plants and they didn't want to have to make them load follow; in the end nuclear got scaled wayyyy back.

Apart from the huge economic risks of a major meltdown, nuclear power also has the waste problems, which have never really had any good solutions, only least bad ones; which still weren't very good.

[chiralSPO]

At the moment I can't remember who to attribute this to, but there is a quote or saying out there along the lines of:

"I am a firm believer that nuclear fusion will ultimately be the only source of power used by the people of Earth--after all, we already have the reactor!"


In all seriousness, with the exception of radioactive materials and geothermal power, all of our energy is originally solar. We just need to develop more efficient ways of capturing, storing and distributing that energy, and we would have access to an almost unlimited  supply of energy (several orders of magnitude more than our current demands.)

[alancalverd]

In all seriousness, with the exception of radioactive materials and geothermal power, all of our energy is originally solar. We just need to develop more efficient ways of capturing, storing and distributing that energy, and we would have access to an almost unlimited  supply of energy (several orders of magnitude more than our current demands.)

Plants do it very well, and you can eat them too. The problem is that there are too many people. But that problem can be solved by simply doing nothing - make fewer people. Alas, however, there is no profit to be made by such a simple solution, and a world with a small population of well-fed, contented people would have no need of priests, politicians, and other parasites, so it won't happen because people are individually clever but collectively stupid.

[wolfekeeper]

Plants are actually not that good at photosynthesis; their conversion efficiency for solar energy to plant energy is only about 1-3% or so, whereas solar panels are ~15-45% or more. Some of that is probably because they need the energy for metabolism; but the end result is the same; they suck for what we as humans want from them.

[Scottish Scientist]

Canal lining and boulder trap



To maximise the water flow velocity, canals are lined to slow erosion. Concrete is one lining material often used to allow for the highest water flow velocities, though engineering guidelines commonly recommend designing for significantly slower maximum flow velocities than 10 m/s, even with concrete lining.

Designing for a slower maximum flow velocity requires a wider canal to maintain the maximum volume flow rate and is expensive in construction costs.

Water flowing at 10 m/s has the power to drag large – in excess of 10 tonnes – boulders along the bottom of a canal with the potential of eroding even concrete, so I suggest that the bottom 6 metres width of the lining, (3 m either side of the corner of the V) may be specially armoured with an even tougher lining material than concrete and/or include bottom transverse barriers of 2 metres depth to impede the flow along the corner of the V and trap boulders, smaller stones and gravel, in which case the water flow is more precisely modelled for Manning formula calculations as a trapezoidal canal with a bed width equal to the 4 metre width of the top of bottom transverse barrier (“boulder trap”) and a 2-metre smaller depth from the top of the boulder trap to the water surface.

Main Dam


Click to view a larger image -  https://scottishscientist.files.wordpress.com/2015/04/strathdearndam.jpg

The image shows the location of the main dam at latitude 57°15’16.2″N, decimal 57.254501°, longitude 4°05’25.8″W, decimal -4.090506°.

Click to view location on Google Maps -

NOPE - MY LINK TO GOOGLE MAPS IS BEING BLACKLISTED
but I've got a work-around via tinyurl
http://tinyurl.com/StrathdearmDamGoogleMaps

Assuming the dam would be twice as wide as its height below the dam top elevation of 650 metres, the superficial volume is estimated at 80 million cubic metres, not including the subterranean dam foundations which would be built on the bedrock after clearing away the fluvial sediment.

There are better technologies on the way which will wipe out the point of it before it could be built.

Well the "long-life" electrical battery has been such a favourite topic for marketing hyperbole for so many decades that scientists are naturally sceptical of any such new claims.

I was thinking about two things: nuclear fusion power stations,

So impractical as to not even be worth discussing. In my opinion, that will never be in place. I regret that Prof Brian Cox has been allowed air time on the BBC to mislead popular science viewers about this topic. Well I suppose he is more entertaining than a lot of the other rubbish on the box, but still - there's no substitute for practical applied science.

and battery storage optimised not for power to weight ratio but for low cost bulk storage (there are promising noises coming from people working on that). Both of these will be in place before you can build your monster.

Well we've heard promising noises for decades about this. I'm not getting my hopes up.

What is certain is that your giant fish tank would meet with enormous opposition for a variety of obvious reasons. You're talking about a dam 300m high and 2km long - an earthquake of 6 on the Richter scale is not an impossibility in that location, so I wouldn't want to live downhill from there.

It should be possible to build a dam as strong as the surrounding mountains, to withstand any earthquake which the mountains endure.

Admittedly, for people living near such big dams, repeated minor earthquakes arising from reservoir induced seismicity
http://en.wikipedia.org/wiki/Induced_seismicity#Artificial_lakes
may cause fear and alarm, at least until such time as the locals get used to it.

The production of concrete generates 410 kg of CO₂ per m³.

A dam is roughly triangular in section with base width equal to its height,

I would place that configuration on the experimental side of the experimental-versus-conservative design boundary for dam footprints, which I would place at the ratio of base width equal to twice its height, which is how I've drawn my dam's footprint in my above diagram.

The issue is blast waves normal to the dam wall - with the 
"width = 2 x height"
or wider configurations, the normal shock is directed into the ground, harmlessly and foiling any sabotage of the dam.

Any narrower than w=2h and the normal shock wave reaches the opposite dam wall above the ground which can fail in tension as the shock wave is reflected from opposite wall, as was demonstrated in the WW2 Dam Busters raid.

so we are looking at a carbon footprint of 37 million tonnes of carbon dioxide for the dam,

You appear to have assumed a dam volume of 90 million cubic metres, which is closer to my estimate than expected because
a) the dam is effectively smaller near its edges because the geography is higher
b) my 80 million cubic metres doesn't include dam foundations so the total including foundations could easily exceed your 90 million cubic metres.

plus probably twice as much to line the canal.

Well I can't agree with this estimate. What did you assume for the canal length, lining area and thickness?

If the depth of the canal water is 88 metres and ignoring any freeboard above the waterline.

Length of lining of canal up the 45 degree slope = √( 2 x 88 x 88) = one slope 124.45 m
Two slopes = 248.9 call that 249m
Canal length 30km = 30,000 metres
Lining area = 30,000 x 249 = 7.47 x 10^6 m^2

Volume of lining per metre thickness is about 7.5 million metres cubed

So even if the lining were 1 metre thick - more than it needs to be I think - that would only be 7.5 million metres cubed, less than 1/10th of the dam volume.

Yet you estimate the canal needs twice the concrete for the dam. Why? Does the canal lining have to be 20 metres thick? Or has one of us got our sums wrong?

plus whatever it takes to get the concrete to site.

Plus fuel for the construction equipment and explosives to blast rock.

I guess at least 150 megatonnes.

Really?

How much wind energy is required to offset this?

Well it is your figure so you work it out. This link
http://www.electricityinfo.org/co2emissions.php
suggests that the average CO₂ emission is 470g/kWh of electricity generated.

I'll work out how much CO₂ my dam will save if used as part of a renewable-only generation system for the equivalent peak-power of 264 GW which equates to an average power capacity of 264/1.6 = 165GW

Annual CO₂-free energy produced is 165 x 24 x 365 = 1.445 x 10^6 GW-hours = 1,445 TerraWatt-hours = 1.445 PetaWatt-Hours (PW-hours)

CO₂ emissions 470g/kWh
= 470Kg/MWh
= 470 tonnes / GWh

So that's an annual CO₂ saving of 470 x 1.445 x 10^6 tonnes CO₂ = 679 million tonnes CO₂

Remember that this project doesn't generate any energy, it merely stores energy generated elswhwere, so there's no "carbon offset" involved.

This pumped-storage hydro scheme would allow intermittent renewables to supply power 24/7 so it should get part of the credit for the carbon dioxide not emitted.

Nuclear power has the lowest carbon footprint of all energy sources, at about 4 gram per kWh so you would need 37,500 GWh of additional free wind energy to repay the carbon cost of building the project. Except that wind actually has a higher carbon footprint than nuclear, so if you wanted to reduce the overall carbon emission of the electricity grid you would do better to replace all the fossil plant with nuclear: no storage problem, no additional land requirement, and no additional transmission grid capacity.

What is the carbon footprint of Chernobyl or Fukushima and who is wasting time counting that when the radiation poisoning footprint of a nuclear disaster is what matters most anyway?

But the SNP is pledged to a non-nuclear Scotland!

I favour retention of the British nuclear deterrent on the Clyde.


 [^]

[jccc]

maybe build a solar highway/belt around the equator? floating kind?

[alancalverd]

I'll work out how much CO2 my dam will save if used as part of a renewable-only generation system for the equivalent peak-power of 264 GW which equates to an average power capacity of 264/1.6 = 165GW

But (a) you state we only need an average of about 60 GW and (b) wind currently produces rather less than one third of its peak capacity - and the best sites have already been used.

Note that your dam won't save (i.e. generate or reduce the need for) electricity, only embarrassment. 


http://nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html

Calculated deaths per Terawatt hour

Wind power proponent and author Paul Gipe estimated in Wind Energy Comes of Age that the mortality rate for wind power from 1980–1994 was 0.4 deaths per terawatt-hour. Paul Gipe's estimate as of end 2000 was 0.15 deaths per TWh, a decline attributed to greater total cumulative generation.

Hydroelectric power was found to to have a fatality rate of 0.10 per TWh (883 fatalities for every TW·yr) in the period 1969–1996

Nuclear power is about 0.04 deaths/TWh.

So if we add hydropower storage to wind, it's altogether about 6 times more dangerous than nuclear.

[wolfekeeper]

I'll work out how much CO2 my dam will save if used as part of a renewable-only generation system for the equivalent peak-power of 264 GW which equates to an average power capacity of 264/1.6 = 165GW

But (a) you state we only need an average of about 60 GW and (b) wind currently produces rather less than one third of its peak capacity - and the best sites have already been used.

That may or may not be the case, but in any case there's something called 'repowering' where you replace wind turbines with bigger ones.

Note that your dam won't save (i.e. generate or reduce the need for) electricity, only embarrassment.

This is a systems question.

The system as whole certainly does generate electricity and not embarassment, and the dam is part of that system. 

http://nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html

Calculated deaths per Terawatt hour

Wind power proponent and author Paul Gipe estimated in Wind Energy Comes of Age that the mortality rate for wind power from 1980–1994 was 0.4 deaths per terawatt-hour. Paul Gipe's estimate as of end 2000 was 0.15 deaths per TWh, a decline attributed to greater total cumulative generation.

Hydroelectric power was found to to have a fatality rate of 0.10 per TWh (883 fatalities for every TW·yr) in the period 1969–1996

Nuclear power is about 0.04 deaths/TWh.

So if we add hydropower storage to wind, it's altogether about 6 times more dangerous than nuclear.

Yes, these are still very small numbers, whereas nuclear power is plausibly more than a billion times more potentially economically destructive in the worst conceivable accident. At one point in Fukushima, they were wondering whether they were going to have to evacuate the whole of Tokyo FFS.

Estimates I've seen are that Ukraine is spending about 5% of its GDP on Chernobyl-related work, to this day.

So, the upside with nuclear power is that your lights work. The downside is that you potentially have to evacuate, lose your job, your house, your pets die chained to a railing until they starve to death, while you go and live in some hell-hole evacuation centre, as happened in Japan.

Thanks... but no thanks.

[alancalverd]

Yes, these are still very small numbers, whereas nuclear power is plausibly more than a billion times more potentially economically destructive in the worst conceivable accident. At one point in Fukushima, they were wondering whether they were going to have to evacuate the whole of Tokyo FFS.

Estimates I've seen are that Ukraine is spending about 5% of its GDP on Chernobyl-related work, to this day.

So, the upside with nuclear power is that your lights work. The downside is that you potentially have to evacuate, lose your job, your house, your pets die chained to a railing until they starve to death, while you go and live in some hell-hole evacuation centre, as happened in Japan.

Thanks... but no thanks.

Ah yes, Fukushima. 16,000 civilians killed by a tsunami that destroyed an entire county, and one power station worker voluntarily received a lethal dose of radiation. My point exactly: water is dangerous, people are irrational. Apart, it seems, from our French neighbours who generate almost 80% of their electricity from nukes with remarkably few cases of hysteria.

Chernobyl wasn't an accident. It was a deliberate experiment to override the safety systems and ignore the operating manual "to see what happens" - which was all in the textbooks anyway.

[alancalverd]

Back to square one: it's 21 April, and so far only 4.5 days this unexceptional month with wind sufficient to generate 2 GW - the running mean is less than 10% of capacity. Time, I think, to review the statistics: as I suggested a few pages back, you need at least 14 days' storage at mean demand if you are going to use electricity as a reliable power source.

Interestingly, governments get upset and start putting emergency schemes into play when at-plant fossil fuel reserves fall below 5 days' worth. One can't help feeling that they know something about it.