SOT Dunkelflaute

No. If its all renewable it needs something like 100x nameplate.

If its nuclear it needs just nameplate

No, it doesn't.

Because:

Gosh - develop a whole new generation of gas-fired plants that are much more efficient you mean? That run efficiently when cold? What are your insights as to how you do this. Planning to repeal the laws of thermodynamics, are you?

Ah - introduce rationing and black market connections to the grid. No bad.

As has been pointed out, already happens.

What are your stunning insights as to how to do this?

Another fool belling the cat.

Why is it that we get these clowns coming on here and spouting TOTAL BOLLOCKS?

...

Well it's an engineering challenge all right, but why is it against the laws of thermodynamics? It doesn't have to run colder, just warm up quicker. Smaller. More of them maybe. Rather like lots of small nuclear reactors being apparently preferred to a few big ones.

So what in the laws of thermodynamic makes the warm-up time what it is and why can't it be different with different design objectives?

We're going to have to build some sort of new power stations aren't we?

nib

In about another ten days, judging by the Beeb weather site.

By which time it will have been two weeks, give or take.

If we assume a demand of 35GW, then for a ten day period that's 8400 GWh, or

And the bugger would be flat after 10 days.

I can't remember. It's almost 60 years since I did my physics degree.

The problems in the UK is that the green lobby is anti-gas and mostly anti-nuclear and the politicians seem only to be listening to this lobby with regards our future energy needs.

Today (4th Nov) gas and nuclear is producing 73% of our electricity needs. Biomass (wood chip imported from Canada and the USA) is generating 8% of our need, but it's hardly green when it comes to producing CO2. Wind has given up throughout the country and is producing around 5%. Solar is producing zero.

Going forward the Government medium to long term policy seems to be close gas, don't build any nuclear and let the existing nuclear continue to their life end. Build more and more wind turbines and solar farms which will also produce very little in weather conditions we are experiencing at the current time.

We do have links with our continental partners who are currently providing around 12% of our needs. This is not guaranteed if they have a shortfall of generation to meet their own needs or if their surplus is feed the other way to other European countries.

Our grid has the capacity to deliver from all our current centralised sources to the population centres. One problem in the UK is that the grid doesn't extend to many of the places future wind farms need to be situated so to get them on line a vast amount of money has to be invested in the distribution network.

Unfortunately after all this investment if the wind doesn't blow we get possibly a maximum of 20% of our electricity needs in the future net zero years, possibly less than 20% if we have all migrated to EVs and electric central heating.

The current main source for domestic central heating in the UK is natural gas. Gas is supplied to around 75% of UK houses.

I imagine these will be less efficient. And as I recall efficiency is defined as (useable energy out) / (energy in). In each of these, energy is directly proportional to absolute temperature, so that gives you (temp-in - temp-out) / (temp-in), all in K. So if we have a boiler whose temp-in is 600C (hottest possible for stainless and steam), output temp is as close to 100C as you can get, that gives you efficiency:

((273+600) - (273+100)) / (273+600) => .57 or 57%

That I would imagine requires three turbine stages (high, medium, low pressure) so you can get the lowest possible output steam temperature. Even that requires a f****ng great cooling tower to condense the steam. So this kit is never gonna be small.

(corrections from real engineers welcome, if needed).

Whereas a radioisotope thermoelectric generator using PU-238 gets sent into space and powers such as Voyager for decades.

They're not actually preferred, just perhaps more likley to be acceptable to those whose belief systems appear no different to those of the 17th C, when they ran around believing in witchcraft, instead of believing that nukes are evil.

Thermal capacity of the device, I imagine.

Yes, and nukes are preferred as, once built, they run for decades, as the French have shown.

This activity is embarrassing for any government. It says that a non-government body is able to pay for power generation where a government cannot.

I don't know about where you live, but where I live, NO civil engineering project finishes on time any more. At this point, why would a nuke be any different ? Even with the SMR concept, I predict five years will be wasted, waiting for the parking lot to be paved.

I got to take a tour of a nuclear reactor site that was under construction. The place was quiet that day. The tour guide said one of the days activities, was sending a robot up the two foot diameter cooling pipe in front of us, "looking for pieces of 2x4". Sabotage! This would be a pipe that had already been welded and Xrayed for weld quality. And now another robot needed to be sent up the pipe and verify the pipe was clear and no materials were in there. (When someone lays a couple pieces of 2x4 in the mouth of the pipe that you can see, the robot has to inspect the entire pipe run.) That reactor was finished some years ago, and is running today.

The reactor has no backup unit. It's a single reactor in a geographic area. Any time this does not generate power, the base load must be met by another generation types. Most likely, hydro power from river generation, is the fallback. This picture shows the graph of output versus year. Showing how a reactor can let you down, and you need 2X nameplate for your grid design. During these multi-year outages, all the smaller pipes are replaced in the core. A good deal of the work is done with robots, as it wouldn't be safe to walk around in there and lay pipe. Since they have done a number of these, the recipe for the work is known.

This example of one of our turbine halls, ran continuously for three years, before being taken offline. Now that's an example of a baseline generation capability. No f****ng around turning it OFF and ON :-) That's because other units up the street from it, could be offline for a rebuild. With continuous refueling (robot loads new fuel bundles while running), this thing can keep up a head of steam for three years. I don't think all of them got run this way, but this one did. Bar bet maybe ?

And, given that Dunkelflauten can follow each other, how on Earth would it be recharged? Where would the energy come from? This is winter and we’re power short, we just don’t have a 2 or 3x grid to supply that power. And it would be a huge waste of resources to build it.

Typical greenie nut jobs, got no idea and Can’t Do Sums.

Same for me, but I think I can just about remember!

nib

At the time of writing this, Gas is producing 22GW and Wind is producing

The TNP Gridwatch graphs show that this current Dunkelflaute started late morning of the 28th Nov and is still continuing. That’s 8 days where Wind has failed and Solar isn’t worth mentioning. An estimate suggests that Gas has made up an average of 10GW over that time.

That’s some battery! And when the Dunkelflaute ends, Gas will have to run flat out to recharge it ready for the next one. Two winters ago we had three such 14-day Dunkelflauten, with little chance to recharge the batteries.

Numbers, eh? You love ‘em or hate ‘em.

You are siding with Spike, who has demonstrated that he doesn't understand the laws of thermodynamics.

All you need to do now is show your working.

Because the whole justification for renewables rests on carefully crafted bullshit

And its nodding dogs sagely agreeing with each other on how it will 'save the planet' (whatever that means) that are convincing people with their Bandar Logic ...They all say it, so it must be true.

And the most terrifying fact is that since Blair, academic institutions are flooded with political propagandists and no one is taught to think for themselves. They all just get full Marx.

In short today's 'educated' population isn't able to tell truth from bullcrap.

So they just regurgitate all the bullcrap they have been fed.

And here we are.

It doesn't matter. A smaller turbine may warm up faster, but it loses energy when running.

Big things stay hot longer. Like the core of the Erath still molten after 4 billion years compared with a pin head.

So fast warm up is a trade off for final efficiency.

OCGT are half the price to build and maintain and are fully up to temp in 15 minutes. But they use nearly twice as much gas.

Thus making renewables pretty pointless, since there is no net reduction in emissions.

See above.

Yes, Nuclear ones.

And no more renewables.

There is nothing a grid of nuclear power stations cannot do worse, with less reliability, more expense and more emissions and environmental damage than by adding renewable energy to it.

with a CCGT gas the first stage turbine is gas at alarmingly high temperatures like 1000°C

There are some actual engineering advantages. The chief one being that because they are small they lose heat faster and dont meed so much cooling under SCRAM., Therefore they don't need emergency cooling pumps once shut down. Convection alone will cool the core thus they can be deprived of all power and shut down and survive.

They are however less efficient and (often) require more enriched fuel.

If it hadn't caught fire.

That amount of energy storage is several megatons of energy.

FWIW whilst looking at the walpole substation out in the sticks, see this let are building a Condenser there to help iron out the grid they are installing reciprocating gas engines that seem self contained and are rapid start.

Nothing that powerful and as said just an observation.

I see no mention there of reciprocation. Its easier to just use a standard gas turbine