Scrutable

Grumble wrote: ↑

Sat Nov 16, 2019 7:39 pm

PWRs are despatchable, or they wouldn’t be able to be used on aircraft carriers and subs. They aren’t typically used that way, and they’re a bit slower to react than a CCGT, but there’s nothing to stop them being used that way. Cheap solar with diurnal shifting isn’t available in the U.K. where I live, not to the extent needed anyway.

My point was not that dispatchable nukes are impossible (they have them in the French reactor fleet as well as in subs and carriers), it was that they are even more horrendously expensive than standard nukes. Not only are they more complex to make, the electricity they make ends up being much more expensive. The cost of electricity from a nuclear reactor is mainly the cost of paying back the capital to make the thing, as the marginal costs of production are low in comparison. That means you want your reactor running and making money 24/7 over its lifetime. If you run it at a 50% capacity factor, you effectively have to double the cost of the electricity you sell to pay back the capital. Hinkley C isn't dispatchable, nor are any other reactors under construction.

Apparently the original plan for the French reactor fleet was for it to be around 3 times the size it is, and use it for everything and anything, "tout-éléctrique, tout-nucléaire", including space heating, transport, oil and more. That would have significant chunks of the reactor fleet sitting idle during summer. They basically stalled the roll out when they hit around 75% of existing power generation without any significant replacement of space heating. Which was more or less the point where they would have had to do a decent amount of load following. Note that they are now planning winding down their reactor fleet to 50% generation, because Arriva and EDF are incapable of rolling out the new non load following EPRs anywhere near on cost or on time.

As for solar, no we don't have much, but we have some of the richest wind resources in the world. Overbuild cheap offshore wind turbines, sell that to Norway when the wind is blowing, buy their hydro when it isn't.

Oh, and insulate the f.ck out of every building in the UK.

I take your point about trying to repay the capital cost being a reason to run nukes as much as possible, but I don’t know what you mean about it being harder and more expensive to make them dispatchable? You can get more or less power from a PWR by putting the control rods further in or out. You can also run the turbines up or down which draws more or less power and has the effect of varying the moderating effect of the water. That’s built in. The extra cost of naval PWRs is more to do with making them so you don’t need to refuel them for many years because unlike a civil plant you have to cut a big hole in your vessel to take a fuel rod out.

Does your cost for nuclear power generation of £92.50/MWh include the disposal costs?

Fossil fuel costs have gone up, largely because people have started to include clean-up costs in the calculations of generation costs (or at least carbon tax, rather than actual clean-up).

Renewable power tends to have lower clean-up costs, making renewable power generation cheaper partly because it's come down in cost and partly because the decommissioning of a wind or wave turbine is so much cheaper than the decommissioning of a fossil fuel power station.

Nuclear generation costs can't include accurate clean-up costs, because no-one really knows the actual clean-up costs for disposing and treating nuclear fuel. Oh, the numbers have been crunched on how long nuclear fuel rods *should* take to be made safe, but seeing as no commercial fuel rod ever used is yet safe, all the costs are estimates. There has been a big step forward in vitrification to reduce clean-up costs, but then no-one's sure how long the vitrified waste has to be stored for; some estimates are multiple thousand years in deep mines - how do we ensure that the waste/mines stay safe for that period of time?

If you are regularly ramping a nuclear plant over the short intervals needed for load following, you are putting a f.ck tonne of thermal stress onto the whole system. You need to make the piping, the heat exchangers, the turbines, the containment systems etc... more robust than if the plant runs at constant temperature and powers up and down over longer intervals for maintenance.

Subs and carriers do it, but they are a special case where you don’t mind spending much more per kWh given the advantages they yield.

BTW, the same logic applies to coal plants, though their marginal cost of generation is higher. Their is a lot of capital tied up in a coal plant and you don’t want them load following for the same reasons.

Boustrophedon wrote: ↑

Fri Nov 15, 2019 8:29 pm

Doesn't work with natural gas. Acetylene tends to dismantle can.

CLEAPSS insist ONLY natural gas?

Martin_B wrote: ↑

Sun Nov 17, 2019 1:43 am

Does your cost for nuclear power generation of £92.50/MWh include the disposal costs?

Fossil fuel costs have gone up, largely because people have started to include clean-up costs in the calculations of generation costs (or at least carbon tax, rather than actual clean-up).

Renewable power tends to have lower clean-up costs, making renewable power generation cheaper partly because it's come down in cost and partly because the decommissioning of a wind or wave turbine is so much cheaper than the decommissioning of a fossil fuel power station.

Nuclear generation costs can't include accurate clean-up costs, because no-one really knows the actual clean-up costs for disposing and treating nuclear fuel. Oh, the numbers have been crunched on how long nuclear fuel rods *should* take to be made safe, but seeing as no commercial fuel rod ever used is yet safe, all the costs are estimates. There has been a big step forward in vitrification to reduce clean-up costs, but then no-one's sure how long the vitrified waste has to be stored for; some estimates are multiple thousand years in deep mines - how do we ensure that the waste/mines stay safe for that period of time?

Sometimes I really wish the Like button had been retained, and then I wouldn't have to type that's what I was going to say.

And in terms of their 'greenness' of production, does it allow for the CO2 cost of the concrete used to make them, and then seal them at the end of their life. I know it's often seen as a 1off cost, to be ignored in the grand scale of things, but it's vast.

Even with all the concrete nuclear is still very much a low carbon energy source. And that’s the main point really, I don’t believe we can get to a point of 100% renewables because we need something like 1000x the current installation base to cover low wind days, or we need massive amounts of storage. We can get further with more wind and solar and more storage, but to provide 100% low carbon electricity we need nuclear in the mix. I don’t think we’ll get 1 TWh of storage, we might get up to the GWh range but that doesn’t last all that long. We’re currently in the MWh range. Can we really use Norway as our storage? I assume this would be pumped hydro, I don’t know what capacity they have?

Fusion will have the same issues of large capital costs to pay off, assuming it happens.

Grumble wrote: ↑

Mon Nov 18, 2019 12:43 pm

Even with all the concrete nuclear is still very much a low carbon energy source. And that’s the main point really, I don’t believe we can get to a point of 100% renewables because we need something like 1000x the current installation base to cover low wind days, or we need massive amounts of storage. We can get further with more wind and solar and more storage, but to provide 100% low carbon electricity we need nuclear in the mix. I don’t think we’ll get 1 TWh of storage, we might get up to the GWh range but that doesn’t last all that long. We’re currently in the MWh range. Can we really use Norway as our storage? I assume this would be pumped hydro, I don’t know what capacity they have?

Fusion will have the same issues of large capital costs to pay off, assuming it happens.

However, you seem to be assuming that nuclear power can carry the base-load in the same way that coal-fired power stations can, although with greater ability to turn-up and down the power generation to meet peak requirements. Nuclear power can't do this. The best nuclear power stations have less than 75% availability. (I can't tell you how I know this, as I've signed the Official Secrets Act!) Nuclear power really isn't the answer to provide base-load power to renewables.

Pumped hydro can be the answer in some places. New Zealand, for example, provides significant peak power generation through the release of pumped hydro, and *could* provide close to 100% of power through renewables, but maintains some non-renewable power generation to ensure a variety of power generation options. New Zealand is an extreme case (lots of water availability, low population density), but somewhere like Scotland or Norway could also do likewise. Norway maintains it's petroleum industry (quite a large number of North Sea platforms of significant capacity) to provide not just power generation diversity but also income through sales to foreign countries and in order to try and build-up their national surplus.

In theory, there is enough wave energy off the coast of west Scotland to provide sufficient power for the entire United Kingdom. Extracting that energy would be troublesome; (you can't extract all of the energy from the wind or a wave, as that would stall the air/water behind the turbine and prevent any more air/water going through the machine.)

Martin_B wrote: ↑

Mon Nov 18, 2019 2:37 pm

In theory, there is enough wave energy off the coast of west Scotland to provide sufficient power for the entire United Kingdom. Extracting that energy would be troublesome; (you can't extract all of the energy from the wind or a wave, as that would stall the air/water behind the turbine and prevent any more air/water going through the machine.)

For Wind, this is known as the Betz limit

Just under 60% for wind, not sure what it would be for tidal power.

For wave power it's different, as the direction of motion for a wave is up and down, and 'still water' behind the generator wouldn't be a fundamental problem.

science_fox wrote: ↑

Mon Nov 18, 2019 9:51 am

Martin_B wrote: ↑

Sun Nov 17, 2019 1:43 am

Does your cost for nuclear power generation of £92.50/MWh include the disposal costs?

Fossil fuel costs have gone up, largely because people have started to include clean-up costs in the calculations of generation costs (or at least carbon tax, rather than actual clean-up).

Renewable power tends to have lower clean-up costs, making renewable power generation cheaper partly because it's come down in cost and partly because the decommissioning of a wind or wave turbine is so much cheaper than the decommissioning of a fossil fuel power station.

Nuclear generation costs can't include accurate clean-up costs, because no-one really knows the actual clean-up costs for disposing and treating nuclear fuel. Oh, the numbers have been crunched on how long nuclear fuel rods *should* take to be made safe, but seeing as no commercial fuel rod ever used is yet safe, all the costs are estimates. There has been a big step forward in vitrification to reduce clean-up costs, but then no-one's sure how long the vitrified waste has to be stored for; some estimates are multiple thousand years in deep mines - how do we ensure that the waste/mines stay safe for that period of time?

Sometimes I really wish the Like button had been retained, and then I wouldn't have to type that's what I was going to say.

And in terms of their 'greenness' of production, does it allow for the CO2 cost of the concrete used to make them, and then seal them at the end of their life. I know it's often seen as a 1off cost, to be ignored in the grand scale of things, but it's vast.

And the energy cost of maintaining the waste storage until its safe. Or in the case of Fukoshima, the freezing of the ground in an attempt to contain the contaminated water.

Let's not bother with wave energy. The time for experimental installations is long gone - we are now forced into mass rollout of proven technology across the next 10 years. We've got the technology we need, and far more attractive prices than we could have ever believed even five years ago.

The sea is too unforgiving. The damage to installations in storms, plus the long term effect of salt, pretty much rules out wave energy. Tidal might have worked, but with the fizzling out of the Swansea lagoon there's nothing on the horizon in the timescales we need.

Martin_B wrote: ↑

Mon Nov 18, 2019 2:37 pm

you seem to be assuming that nuclear power can carry the base-load in the same way that coal-fired power stations can, although with greater ability to turn-up and down the power generation to meet peak requirements. Nuclear power can't do this. The best nuclear power stations have less than 75% availability. (I can't tell you how I know this, as I've signed the Official Secrets Act!) Nuclear power really isn't the answer to provide base-load power to renewables.

I don’t think I am assuming that, I am assuming that nuclear could make up a higher % of the load than it currently does. It doesn’t often get as far as 30% and that’s at times of lowest demand. I would suggest that could increase, but at this point I probably need to read some analysis papers to see if anyone agrees with me. I’ll try not to read analysis that only agrees with me.

lpm wrote: ↑

Mon Nov 18, 2019 4:24 pm

Let's not bother with wave energy. The time for experimental installations is long gone - we are now forced into mass rollout of proven technology across the next 10 years. We've got the technology we need, and far more attractive prices than we could have ever believed even five years ago.

The sea is too unforgiving. The damage to installations in storms, plus the long term effect of salt, pretty much rules out wave energy. Tidal might have worked, but with the fizzling out of the Swansea lagoon there's nothing on the horizon in the timescales we need.

Yes the Swansea and Severn lagoons were promising. I think they would actually have been worth the habitat loss for the CO₂ reduction.

lpm wrote: ↑

Mon Nov 18, 2019 4:24 pm

Let's not bother with wave energy. The time for experimental installations is long gone - we are now forced into mass rollout of proven technology across the next 10 years. We've got the technology we need, and far more attractive prices than we could have ever believed even five years ago.

The sea is too unforgiving. The damage to installations in storms, plus the long term effect of salt, pretty much rules out wave energy. Tidal might have worked, but with the fizzling out of the Swansea lagoon there's nothing on the horizon in the timescales we need.

Placing tidal turbines or experimental wave stuff alongside offshore and near-shore wind installations could be an interesting way to reduce some of the costs of developing and proving new technologies.

dyqik wrote: ↑

Mon Nov 18, 2019 7:02 pm

lpm wrote: ↑

Mon Nov 18, 2019 4:24 pm

Let's not bother with wave energy. The time for experimental installations is long gone - we are now forced into mass rollout of proven technology across the next 10 years. We've got the technology we need, and far more attractive prices than we could have ever believed even five years ago.

The sea is too unforgiving. The damage to installations in storms, plus the long term effect of salt, pretty much rules out wave energy. Tidal might have worked, but with the fizzling out of the Swansea lagoon there's nothing on the horizon in the timescales we need.

Placing tidal turbines or experimental wave stuff alongside offshore and near-shore wind installations could be an interesting way to reduce some of the costs of developing and proving new technologies.

You won't necessarily be optimising the placement of the wave thingumys if you do that, because you've (ideally) optimised the placement of the wind turbine.

bjn wrote: ↑

Mon Nov 18, 2019 8:21 pm

dyqik wrote: ↑

Mon Nov 18, 2019 7:02 pm

lpm wrote: ↑

Mon Nov 18, 2019 4:24 pm

Let's not bother with wave energy. The time for experimental installations is long gone - we are now forced into mass rollout of proven technology across the next 10 years. We've got the technology we need, and far more attractive prices than we could have ever believed even five years ago.

The sea is too unforgiving. The damage to installations in storms, plus the long term effect of salt, pretty much rules out wave energy. Tidal might have worked, but with the fizzling out of the Swansea lagoon there's nothing on the horizon in the timescales we need.

Placing tidal turbines or experimental wave stuff alongside offshore and near-shore wind installations could be an interesting way to reduce some of the costs of developing and proving new technologies.

You won't necessarily be optimising the placement of the wave thingumys if you do that, because you've (ideally) optimised the placement of the wind turbine.

No, but you'll have saved a big chunk of infrastructure. Which is particularly important for prototyping, or pilot installations.

Gfamily wrote: ↑

Mon Nov 18, 2019 2:59 pm

Martin_B wrote: ↑

Mon Nov 18, 2019 2:37 pm

In theory, there is enough wave energy off the coast of west Scotland to provide sufficient power for the entire United Kingdom. Extracting that energy would be troublesome; (you can't extract all of the energy from the wind or a wave, as that would stall the air/water behind the turbine and prevent any more air/water going through the machine.)

For Wind, this is known as the Betz limit

Just under 60% for wind, not sure what it would be for tidal power.

For wave power it's different, as the direction of motion for a wave is up and down, and 'still water' behind the generator wouldn't be a fundamental problem.

That's the one. Couldn't remember the name last night. (And I'd had a glass or two of wine!)

Grumble wrote: ↑

Mon Nov 18, 2019 12:43 pm

Even with all the concrete nuclear is still very much a low carbon energy source. And that’s the main point really, I don’t believe we can get to a point of 100% renewables because we need something like 1000x the current installation base to cover low wind days, or we need massive amounts of storage. We can get further with more wind and solar and more storage, but to provide 100% low carbon electricity we need nuclear in the mix. I don’t think we’ll get 1 TWh of storage, we might get up to the GWh range but that doesn’t last all that long. We’re currently in the MWh range. Can we really use Norway as our storage? I assume this would be pumped hydro, I don’t know what capacity they have?

Fusion will have the same issues of large capital costs to pay off, assuming it happens.

Actually, as far as I could make out when I looked at this about a year or so ago, very little. I was reading original documents from the Norwegian Water Resources and Energy Directorate (NVE: http://www.nve.no), so I could easily have missed something, but it looked like, although Norway has lots of hydro power, it has very little to no pumped storage ( https://www.nve.no/energiforsyning/kraf ... f=mainmenu 1626 power-generating facilities generating 135 TWh/year and 30 pumps using 0.16 TWh/year.). That could be changed, but it is not a short-term, or cheap project.
The electric power generating companies that own the hydro generators in Norway work very hard to maximise their profits, so sell Norwegian hydro generated power to neighbouring countries when demand is high, and buy nuclear and coal generated power from neighbours when demand is low, keeping the water in the upstream reservoirs. So despite the apparently impressive statistics that Norway generates roughly the same amount of electric power as it uses, the reality is a lot more complicated than that, and Norway runs on Swedish generated nuclear power and German coal and wind power for a lot of the time, making the maximum profit for the hydro generator owners (which are not 100% Norwegian) out of the hydro power. In addition, the carbon credits that accompany the hydro-power are split off and sold separately, so, for example, a Polish brown coal burner can buy carbon credits and sell 'green power', and Norwegian consumers, who believe they are using 'green' power, are actually not. This is separate to the 'renewable energy certification' scheme.
Converting hydro to pumped-storage is not simply a case of running the generators in reverse. While you can do that with specially designed generators, the Norwegian plants are not designed to do that. You could install pumps, and add extra tunnels/pipeline to send the water up to the reservoirs again, but that has not (as far as I can tell) been done on a large scale.

The above is mostly original research done by me, trying to read various Norwegian documents and spreadsheets, so I apologise for any errors, and would be grateful if bmforre (or others) could confirm or deny and/or correct what I've said.

So, as far as I can make out, hydro-power generated in Norway can act as a quickly dispatchable resource for the UK, once the UK-Norway interconnector is up and running, but I don't think it is possible to use it as remote pumped storage,

There is a separate interconnect between Norway and England. The North Sea Link. Also 1.4GW.

There are mumbles in the wiki article about directly connecting up wind farms to it as well.

Keeping the hydro in reserve for when other generation isn’t available means the market is working for the companies that own them as well as for society more generally. How a mixed grid should work.

Pucksoppet wrote: ↑

Tue Nov 19, 2019 9:33 am

Grumble wrote: ↑

Mon Nov 18, 2019 12:43 pm

Even with all the concrete nuclear is still very much a low carbon energy source. And that’s the main point really, I don’t believe we can get to a point of 100% renewables because we need something like 1000x the current installation base to cover low wind days, or we need massive amounts of storage. We can get further with more wind and solar and more storage, but to provide 100% low carbon electricity we need nuclear in the mix. I don’t think we’ll get 1 TWh of storage, we might get up to the GWh range but that doesn’t last all that long. We’re currently in the MWh range. Can we really use Norway as our storage? I assume this would be pumped hydro, I don’t know what capacity they have?

Fusion will have the same issues of large capital costs to pay off, assuming it happens.

Actually, as far as I could make out when I looked at this about a year or so ago, very little. I was reading original documents from the Norwegian Water Resources and Energy Directorate (NVE: http://www.nve.no), so I could easily have missed something, but it looked like, although Norway has lots of hydro power, it has very little to no pumped storage ( https://www.nve.no/energiforsyning/kraf ... f=mainmenu 1626 power-generating facilities generating 135 TWh/year and 30 pumps using 0.16 TWh/year.). That could be changed, but it is not a short-term, or cheap project.

It's a lot cheaper than building new pumped storage, or probably new other method storage sites. You've got the upper dam and reservoir, the generators, and the lines connecting to the grid already. The big outlays would be a lower water storage pond (probably much cheaper than the high dam and reservoir), pumps and plumbing*, and control and switch gear to reverse the direction of the grid connections.

*or whatever the appropriate word here is

Martin_B wrote: ↑

Mon Nov 18, 2019 2:37 pm

Pumped hydro can be the answer in some places. New Zealand, for example, provides significant peak power generation through the release of pumped hydro...

Do you have a citation for that? There is lots of hydro generation, certainly, but when I've gone looking for figures on pumped storage I've mostly found articles saying that we ought to consider doing it.

dyqik wrote: ↑

Tue Nov 19, 2019 1:10 pm

Pucksoppet wrote: ↑

Tue Nov 19, 2019 9:33 am

Grumble wrote: ↑

Mon Nov 18, 2019 12:43 pm

Even with all the concrete nuclear is still very much a low carbon energy source. And that’s the main point really, I don’t believe we can get to a point of 100% renewables because we need something like 1000x the current installation base to cover low wind days, or we need massive amounts of storage. We can get further with more wind and solar and more storage, but to provide 100% low carbon electricity we need nuclear in the mix. I don’t think we’ll get 1 TWh of storage, we might get up to the GWh range but that doesn’t last all that long. We’re currently in the MWh range. Can we really use Norway as our storage? I assume this would be pumped hydro, I don’t know what capacity they have?

Fusion will have the same issues of large capital costs to pay off, assuming it happens.

Actually, as far as I could make out when I looked at this about a year or so ago, very little. I was reading original documents from the Norwegian Water Resources and Energy Directorate (NVE: http://www.nve.no), so I could easily have missed something, but it looked like, although Norway has lots of hydro power, it has very little to no pumped storage ( https://www.nve.no/energiforsyning/kraf ... f=mainmenu 1626 power-generating facilities generating 135 TWh/year and 30 pumps using 0.16 TWh/year.). That could be changed, but it is not a short-term, or cheap project.

It's a lot cheaper than building new pumped storage, or probably new other method storage sites. You've got the upper dam and reservoir, the generators, and the lines connecting to the grid already. The big outlays would be a lower water storage pond (probably much cheaper than the high dam and reservoir), pumps and plumbing*, and control and switch gear to reverse the direction of the grid connections.

*or whatever the appropriate word here is

So long as the geography and geology is favourable to having a lower reservoir as well as an upper. That must limit the choices of suitable locations.

Grumble wrote: ↑

Mon Nov 18, 2019 12:43 pm

... I don’t think we’ll get 1 TWh of storage, we might get up to the GWh range but that doesn’t last all that long. We’re currently in the MWh range. Can we really use Norway as our storage? I assume this would be pumped hydro, I don’t know what capacity they have?

Latest first: We don't pump hydro in Norway, water rains down from above and is caught in our large reservoirs. From whence: dispatched.

Storage capacity in this country. According to https://energifaktanorge.no/norsk-energ ... rsyningen/, translated and commented by me:
"Normal year" production: 141 TWh. Trend: Increasing with climate change at present.
Storage capacity ca. 70% of yearly consumption.
That's ca 100 TWh.
While you state

... I don’t think we’ll get 1 TWh of storage ...

in Norway we do have 100 times that.

So it’s a case of it being so wet and rainy why bother pumping?