Naked Science Forum
Non Life Sciences => Technology => Topic started by: acsinuk on 03/08/2024 11:17:47
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Recently visited Dungeness and found that they have not generated power for over a year although the "B" station is totally intact after cooling down. .
We keep being hassled by the government to buy electric cars assuming the electricity to charge the batteries is produced in a green environmentally way. But it is not!!
Look at the gridwatch stats https://www.gridwatch.templar.co.uk/
If you compare it with another statistic site we find that they are different?
https://grid.iamkate.com/
This sunny windy morning 3 August shows that
FUEL GW %
Fossil fuels 5.1 19.2
Renewables 10.0 37.7
Nuclear/other 6.9 26.3
But this assumes that some of our imported power imported from France is nuclear .possibly 12 GW and UK just 4.7GW. as confirmed by gridwatch https://www.gridwatch.templar.co.uk/
We need to get our nuclear stations back up and running quickly to green our grid before spending tax monies on motorway charging stations and electrifying transport.
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We need to get our nuclear stations back up and running
The problem is the radioactive waste that is produced. In the US we still don't have anyplace for long term storage.
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I would prefer to live close to a nuke power plant than a coal burner. I know waste is a problem but surely not intractable. Deep mine storage in ceramic/glass form has been suggested but whether it has ever been implemented I don't know. The reserves of uranium and thorium would power the world for a heck of a long time.
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The problem with nuclear power is the quantity of fossil fuel you need to burn to build a new nuke. It made economic sense in the 1950s when we had functioning coal mines and before oil became the chosen weapon of Allah, but nowadays the financial payback period is too long to attract investment and the energy breakeven is dubious. If you add the political risk of decommissioning and waste disposal, it probably isn't worth the effort.
Never mind. Fusion power is just 20 years away. In 1955, it was only 5 years away! That's progress.
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Jam tomorrow, but not today.
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Plus a Hubble factor!
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Nuclear waste could be stored in waterproof containers at the bottom of Atlantic ocean for millions of years without bothering us.
In fact, I did read somewhere that where the continental shelves collide it may be possible to get the waste reabsorbed inside the planetary crust.
We could place the waste problem on the back shelf for now and get on and green the grid immediately by going nuclear!!
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Nuclear waste could be stored in waterproof containers at the bottom of Atlantic ocean for millions of years without bothering us.
Over a timescale of a million years, the bottom of the Atlantic is not reliably waterproof.
Dumping at sea is illegal- for a reason.
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We could place the waste problem on the back shelf for now and get on and green the grid immediately by going nuclear!!
But see reply #3. You have to burn an awful lot of oil to make a nuclear power station, and even if you ignore the carbon footprint, you may not get your money back.
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Alan, Nuclear submarines are safe so just build a big one and float it into Dungeness under water and connect up to the grid if we cannot rehab the "B" station economically.
Solar and wind cannot be reliable on for power in cold winter nights and we must green the grid..
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Nuclear submarines are safe
Actually, no. The radiation dose to the crew and maintenance personnel would not be acceptable in a permanent civilian unit. And the cost is still prohibitive.
The only sustainable solution is to reduce demand (by reducing the population) and use renewables to generate hydrogen.
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Actually, no. The radiation dose to the crew and maintenance personnel would not be acceptable in a permanent civilian unit. And the cost is still prohibitive.
Nonsense, if the dose is as much as pilots get the government would be sued these days.
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The statutory occupational dose limit is 20 millisievert per year, 20 times the "public" limit. When designing any publicly-accessible facility you need to adopt a dose constraint of about 0.3 mSv/year or less.
Submarine crews and shore maintenance personnel are monitored and rotated to keep their dose "as low as reasonably practicable" given the inevitable exposure associated with their employment, but the reactor shielding for any vehicle is necessarily a compromise between weight and safety, which is why there are no nuclear-powered aircraft. To bring the reactor into a permanent civilian facility you would need to build a whole lot more shielding, which demands concrete and steel, which consume a lot of fossil fuel. On patrol, of course, sea water is a very effective and zero-cost radiation shield when the reactor is running at full steam, so you only need to shield the forward bulkhead (assuming the reactor is at the stern) against maximum flux. You can't run the part-shielded reactor at full chat in a crowded harbor, but you'd need to if it is intended to supply the electricity grid.
Civil aircrew generally receive about 4 mSv/yr but there is some debate over whether this is an employment dose since (a) the source is entirely natural and uncontrollable and (b) it's still within the range of natural background doses to which some populations are exposed (up to 8 mSv/yr in parts of Cornwall, and a lot more in some other countries) with no evidence of harm. So we have monitoring programs and advisory crew rotation but so far, no lawsuits.
Nuclear submarines generally work at about 200 MW, which won't make much impact compared with Drax (biomass) or any of the coal, nuclear or gas stations opened in the last 50 years, which run at 2000 - 4000 MW. You could probably run a big hospital from a submarine.
And rerturning to acsin's plan, why build a submarine anyway? A land-based nuke would be a lot cheaper, though still uneconomic.
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Alan,
" 8 mSv/yr in parts of Cornwall, and a lot more in some other countries) with no evidence of harm. So we have monitoring programs and advisory crew rotation but so far, no lawsuits.".
Exactly correct, the legal requirement is totally OTT and unrealistic. Some people at Chernobyl stayed on and are still alive at age 90 so what on earth are we stating as a safe limit??
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There is no safe limit.
The statutory requirement for third party exposure is based on the ALARA principle, with a cutoff based on what is practicably measurable. We can usually detect 1 mSv/yr arising from a controllable source, against the local natural background which tends to be fairly stable.
It's all subject to ongoing debate. There is evidence that folk who live in a background of high gamma exposure (up to 20 mSv/yr) actually live longer than matched controls at 3 mSv/yr, but where the background is alpha radiation (e.g. Kerala) there seems to be an anomalous incidence of birth defects. So I don't argue with the consensus on this one!
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Exactly correct, the legal requirement is totally OTT and unrealistic.
You didn't understand it, did you?
"as low as reasonably practicable" is realistic by definition.
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So if it is economically impractical to obtain 1 mSv/yr limit, then as many normal places like Cornwall already have 3 mSv/yr, then why not standardise on the Himalayan high altitude limit [were some over 100 year olds lived all their lives] of 20 mSv/yr as a practical limit which I assume would simplify nuclear construction enormously.
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which I assume would simplify nuclear construction enormously.
No!
The simplest model of any sort of radiation is a 1/r2 decrease in intensity with distance from the source. Now if we set 20 mSv/yr as the limit at the fence of a nuclear power station, 100 m from the reactor, what is the dose rate at 10 m, where the employees are?
What we do is always to protect the employees first, then decide whether additional protection is needed for everyone else. And the answer is usually no. Except in the odd case of a partially-shielded reactor on a submarine in dock!
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The simplest model of any sort of radiation is a 1/r2 decrease in intensity with distance from the source. Now if we set 20 mSv/yr as the limit at the fence of a nuclear power station, 100 m from the reactor, what is the dose rate at 10 m, where the employees are?
Cumulative effects, if you live in Cornwall, work in the nuclear industry, fly for 10 hours a week, have a CT scan, enjoy Brazil nuts and go skiing and mountain climbing you may well rack up quite a dose. What we do is always to protect the employees first, then decide whether additional protection is needed for everyone else. And the answer is usually no. Except in the odd case of a partially-shielded reactor on a submarine in dock!
But you are not going to be standing by a reactor for 12 months of the year, it is the same as an x-ray or visiting the chernoblyl reactor, large dose small duration.
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Recently visited Dungeness and found that they have not generated power for over a year although the "B" station is totally intact after cooling down. .
We keep being hassled by the government to buy electric cars assuming the electricity to charge the batteries is produced in a green environmentally way. But it is not!!
Look at the gridwatch stats https://www.gridwatch.templar.co.uk/
If you compare it with another statistic site we find that they are different?
https://grid.iamkate.com/
This sunny windy morning 3 August shows that
FUEL GW %
Fossil fuels 5.1 19.2
Renewables 10.0 37.7
Nuclear/other 6.9 26.3
But this assumes that some of our imported power imported from France is nuclear .possibly 12 GW and UK just 4.7GW. as confirmed by gridwatch https://www.gridwatch.templar.co.uk/
We need to get our nuclear stations back up and running quickly to green our grid before spending tax monies on motorway charging stations and electrifying transport.
Answering your point, wind is significantly cheaper in this country, we could just use wind and make a very substantial reservoir for future years if we install enough, the more you build and operate at any one Tim the cheaper it is. Energy storage is the thing we need to overcome, but the governments are all interested in electric cars, heat pumps and solar.
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we could just use wind and make a very substantial reservoir for future years if we install enough,
There's the weakness - there is no primary "reservoir" in renewables. On a hot or cold day the wind doesn't blow, and the sun only shines half the time. So even if you had a reservoir, like a huge battery farm, you would have to install enough wind power to supply peak demand and recharge the battery, from average wind. Problem is that power output depends on the cube of wind speed, so you need to install several times the peak demand capacity.
And then there's the problem that electricity only accounts for about 30% of UK energy consumption, so when we are fully decarbonised, peak demand will be about 3 times the present level.
There just isn't enough wind!
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we could just use wind and make a very substantial reservoir for future years if we install enough,
There's the weakness - there is no primary "reservoir" in renewables. On a hot or cold day the wind doesn't blow, and the sun only shines half the time. So even if you had a reservoir, like a huge battery farm, you would have to install enough wind power to supply peak demand and recharge the battery, from average wind. Problem is that power output depends on the cube of wind speed, so you need to install several times the peak demand capacity.
And then there's the problem that electricity only accounts for about 30% of UK energy consumption, so when we are fully decarbonised, peak demand will be about 3 times the present level.
There just isn't enough wind!
Round the UK if we made an effort and put turbines all over, made them so they generated during the heavy winds with variable resistance generators, converted the hydrogen close to the turbine and stored it we should have more than enough, if you look at the UK portion of the north Sea, what we have of the channel and what ridiculous amounts off Scotland north and West. I am unsure of how many years we could store but offshore wind does about 33 percent of its plate capacity, so if we put in 200 gw we would be generating 2 years worth per year.
That however is mucho mucho gasso.
Edit: that is just to replace the electricity, times by 3 for inefficiencies.
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So we need to install 600 GW of renewable electricity generators and triple the gas grid capacity. By no means impossible.
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To replace everything, like for like, you require about 120 Hornsea 6gw arrays, double it for reserves and we may just squeeze them in Norway once again will be laughing, France Spain and Portugal will struggle but they have solar to fall back on, Denmark should just about manage, but any country like Germany will have no hope either with solar or wind.
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double it for reserves
No, there are no reserves with renewables. The wind either blows or it doesn't. Any "reserve" must be a battery or gas store.
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double it for reserves
Any "reserve" must be a battery or gas store.
Yes
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But hydrogen is not a compressible gas so totally uneconomical to store unless you mix it with carbon to liquify it?
Hydro is a possibility if we can dam a whole upland valley or 2 ??
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Hydrogen storage is plausible, Germany already stores much of its gas, enough for 3 months winter usage I think, buying during summer when it is cheaper The UK government didn't think that this was worth it so we end up paying through the nose for it, especially when vladimit put in throws hit toys out of the pram.
The problem with hydrogen is that wind energy operates about a third of the time so the UK would need the UK energy usage is about 250 gw so wind would need at least 750gw, double that for storage capacity for a production peak of 1,500gw. That would be about 15,000,000,000 m3 of hydrogen an hour I think. Not impossible but a hydrogen generating and transport infrastructure of that scale is more problematic than the 150,000 wind turbines.
As for hydro storage it is not feasible long term, MGH tells us 1km3 of water 1000m high has 10,000,000,000,000,000 joules or roughly 3,000,000,000 kwh, long enough for 12 hours of UK usage. There are not may places on earth you can achieve such capacity.
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But hydrogen is not a compressible gas
An incompressible gas? Amazing.
On this planet we distribute hydrogen compressed to 300 atmospheres, and it's still a gas, right down to 33K. What is the atmospheric pressure and temperature on your planet, I wonder?
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Germany already stores much of its gas,
From about 1750 to 1965, the UK stored and distributed town gas, consisting of 50% hydrogen, in huge low-pressure collapsible tanks ("gasometers") which have mostly been demolished apart from those overlooking the Oval cricket ground, which are subject to a preservation order.
The gas grid already exists and has been developed and maintained continuously since the 18th century. It was converted from town gas to methane in the 1960s by simply altering the burners, district by district, with no need to dig up the roads, and gradually replacing the generating stations and gas stores with banks of LPG bottles.
The high pressure grid runs at 69 bar and will carry pure hydrogen with no problem. Local compression to 300 bar for road transport is straightforward.
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km3 of water 1000m high has 10,000,000,000,000,000 joules or roughly 3,000,000,000 kwh, long enough for 12 hours of UK usage. There are not may places on earth you can achieve such capacity.
And certainly none in the UK - the highest point is only 1,345 m above sea level!
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The push for electric cars feels a bit premature when we aren't fully set up with green energy to back it up. The grid's still heavily reliant on fossil fuels, and nuclear seems underutilized.
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The push for electric cars feels a bit premature when we aren't fully set up with green energy to back it up. The grid's still heavily reliant on fossil fuels, and nuclear seems underutilized.
I agree, if the uk could manage to keep the wind turbines turning and store the energy for a short period rather than paying for them to be turned off it would signal that the infrastructure was becoming mature enough to handle extra demand.
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The present problem is that we need to maintain fossil and nuclear stations to fill the gap, up to peak demand, when the wind doesn't blow, so we can't reduce their number but as they aren't always working to capacity, they are uneconomic.
When demand is low, it's not a good idea to run down the nukes because they take a long time to run up again, and as Chernobyl demonstrated, the run down needs to be very carefully planned, so at times of low demand we pay wind farms not to generate power when it isn't needed, and there's little point in building more nukes than are required to supply the minimum base load - which we already have.
So from the consumer's point of view, introducing windfarms has just increased the cost of electricity, and from the investor's point of view neither nuclear nor fossil power is a good investment for the future.
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We need to store energy quickly and retrieve at peak demand. The answer is hydro assisted by nuclear .
But Hydro large scale.
Lock Ness is 16 metres above sea level 56 square km and contains ? billions of tons of water.
Loch Locky is 29 metre above sea level 16 square km and contains ? billion tons of water.
So if we drain 1 metre of water from Locky we move 16 thousand million cubic metres/tons down to Lock Ness.
We need to do this transfer in 12 hours and it needs to be a reversible process. i.e. Pumped storage.
There are other examples of Lochs with hydo stations between but these need upgrading to ?9 times the size reversible.
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We need to store energy quickly and retrieve at peak demand. The answer is hydro assisted by nuclear .
But Hydro large scale.
Lock Ness is 16 metres above sea level 56 square km and contains ? billions of tons of water.
Loch Locky is 29 metre above sea level 16 square km and contains ? billion tons of water.
So if we drain 1 metre of water from Locky we move 16 thousand million cubic metres/tons down to Lock Ness.
We need to do this transfer in 12 hours and it needs to be a reversible process. i.e. Pumped storage.
There are other examples of Lochs with hydo stations between but these need upgrading to ?9 times the size reversible.
The point you are missing is that at present the uk uses 250gwh of energy per hour. Now we may be able to reduce this somewhat by electric heat pumps and electric cars, and install 125 gwh of nulcear capacity but we will then have a massivley skewed electricity demand in the winter, (a squint at my gas metre tells me that in the winter 4 months I have used about 800kwh of gas and the summer 4 months under 50kwh). That will still be quite some hydro electric storage. This dam in the alps could store 2,000 gwh if it had storage at the bottom.
https://en.m.wikipedia.org/wiki/Grande_Dixence_Dam#:~:text=The%20Grande%20Dixence%20Dam%20(French,the%20tallest%20dam%20in%20Europe.
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When demand is low, it's not a good idea to run down the nukes because they take a long time to run up again, and as Chernobyl demonstrated, the run down needs to be very carefully planned, so at times of low demand we pay wind farms not to generate power when it isn't needed, and there's little point in building more nukes than are required to supply the minimum base load - which we already have.
Yes and i remember asking a question on here about whether nuclear plants still degrage and loose life span even when not generating, the consensus seemed to be yes. If you have them on 50 percent of the time the cost of your electricity doubles, from what is already expensive.
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We need to store energy quickly and retrieve at peak demand.
No need to store it quickly, but we need to be able to supply mean and peak for up to 5 days at a time when the wind doesn't blow.
It is true that the British Isles are rarely completely becalmed, but power output from a windmill depends on the cube of the wind speed and a machine that can genrate its rated power for say 80% of the time, effectively generates nothing at all for at least 10%. And these are the hottest and coldest days (persistent anticyclone) when electricity supply is most critical.
Occasional sharp peaks are already met by pumped storage, but only for the 20 - 30 minutes it takes to fire up the fossil plants. The beauty of hydrogen storage is that you can modify existing gas stations to use hydrogen with very little extra investment, giving you flexible response and guaranteed fast runup times to continuous working at minimal cost.
Emptying a sea loch is in the realm of tidal power, which despite being around in principle and in a few mechanical tide mills for thousands of years, has never been shown to be economic on the scale of a national grid.
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First things first we need to have 22Gw of nuclear to supply the night minimum load and have just found this article from IET.
https://eandt.theiet.org/2024/07/30/small-modular-reactor-designs-approved-first-step-towards-uk-nuclear-power-expansion
As 10% of the nuclear plant is normally out of service for regular maintenance we need 24Gw to cover the 22Gw night load which will leave 20Gw to top up the day load using wind, solar, tidal and hydro/storage to complete a green grid by 2050.
It is achievable if we push the government to prioritise green grid and backpedal on electrifying transport .
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Hydro storage is useless for the UK. We have no significant mountain valleys, and the little ones we do have are intensively farmed and somewhat populated.
Direct wind and solar are useless because they can't meet peak loads when they occur, only if the wind is blowing at the optimum speed or the sun is shining.
Tidal hasn't produced useful power anywhere in the last 60 years, and any substantial modification to allow controllable tidal power will flood huge areas of productive farmland and essential wetlands.
Re: mini-nukes the regulatory judgements do not guarantee that Rolls-Royce will be granted a site licence or the environmental permits needed to construct a power station based on the designs.
Nuclear power is not an investable business.
I can see no realistic alternative to wind farms with hydrogen storage and distribution.
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You also have to factor energy security into this. Given the current militarism rampaging the globe what would we do if we found ourselves at war and only reliant upon renewables, including nuclear. If somehow our 150,000 10kw wind turbines where sabotaged in someway like nord stream 2 or worse, if we were reliant upon batteries, nuclear and hydrostorage for winter demand we would be in serious trouble. The same problem is there with solar, we could be brought down by contrails.
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The same problem is there with solar, we could be brought down by contrails.
Or by the absence of sunlight for exactly half the year (same anywhere on the planet) plus British weather even during daylight. No need for contrails!
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Or ""chemtrails""!!
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Look at the current reading from the grid to see where the power is being generated at present.
Today is currently, slight breeze and cloud/sunny Monday morning 16 September weather,
Max demand is 35GW. This is generated by 5GW nuclear [mostly French interconnector], 2GW wind, 4GW solar, 4GWBiomass/incinerators, 1GW hydro, 4GW EU interconnectors, 12GW CCGTgas, and 3GW others.
So, to green the grid we need to generate the base 24 hour day and night load using nuclear 24 GW which will be backed up by wind 20GW average and solar 20GW average daytime only plus incinerating plastic waste 10GW with advanced chemical flu scrubbers to remove toxic chemicals. Pumped storage or tidal systems or possibly coal will be needed to completely green the grid.
https://www.gridwatch.templar.co.uk/
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Look at the current reading from the grid to see where the power is being generated at present.
Today is currently, slight breeze and cloud/sunny Monday morning 16 September weather,
Max demand is 35GW. This is generated by 5GW nuclear [mostly French interconnector], 2GW wind, 4GW solar, 4GWBiomass/incinerators, 1GW hydro, 4GW EU interconnectors, 12GW CCGTgas, and 3GW others.
So, to green the grid we need to generate the base 24 hour day and night load using nuclear 24 GW which will be backed up by wind 20GW average and solar 20GW average daytime only plus incinerating plastic waste 10GW with advanced chemical flu scrubbers to remove toxic chemicals. Pumped storage or tidal systems or possibly coal will be needed to completely green the grid.
https://www.gridwatch.templar.co.uk/
Electricity is only 20 percent of uk energy usage, we manage 50 percent of electricity at present from renewables maximum, viz 90 percent of our energy usage is fossil fuel based.
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We could place the waste problem on the back shelf for now and get on and green the grid immediately by going nuclear!!
If my glasses were 10% stronger, I'd be classified as "partially sighted".
And I'm still less short-sighted that your attitude.
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Petrochemicals quote " Electricity is only 20 percent of uk energy usage, we manage 50 percent of electricity at present from renewables maximum, viz 90 percent of our energy usage is fossil fuel based" is nearly correct of course.
Google says Oil: 31.2% Coal: 27.2% Natural gas: 24.7% Hydro (renewables): 6.9% Nuclear: 4.3% Others (renewables): 5%
So what to do after we green the grid is to find alternative sources of fuel which could mean reopening coal mines or burning peat, which we have in abundance of in the UK and as happens in many other parts of the world already..
The alternative is to risk oil/petrol/diesel and gas running out and becoming extremely expensive.
Admittedly, CO2 will be produced but with careful management of flu gases, by carbon capture techniques or seaweed absorption is possibly a way forward
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Carbon capture sounds simple though it is anything but simple. It is costly to implement and generates a lot of "waste", what ever way it is done. The two ways I know of are collection as co2 or as carbonate. If co2 is collected where is it to go?, deep mine storage has been touted but how secure this would be long term, I don't know but I am dubious. To collect it as carbonate would involve huge quantities of a basic substance and would be more secure long term but again huge quantities of waste, albeit relatively innocuous, would have to be dumped. I am not convinced.
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Hydro (renewables): 6.9%
Nope.
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reopening coal mines
Not feasible on a commercial scale. Thanks to Margaret Thatcher there has been no maintenance of deep mines in the UK since the 1970s. Lack of maintenance leads to flooding and collapse from the bottom upwards so an abandoned "soft rock" deep mine cannot be safely reopened.
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To collect it as carbonate would involve huge quantities of a basic substance
..... such as calcium oxide, made by heating calcium carbonate to drive off the carbon dioxide.....or sodium hydroxide, made by electrolysis, using electricity made by, er, burning carbon......
Green plants are the only sensible sinks for CO2, which they turn into food and building materials.