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Author Topic: Gridwatch Overnight Tonight 14/06/18  (Read 2721 times)
oliver90owner
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« Reply #30 on: June 15, 2018, 08:07:26 AM »

AZPS,

Sorry but something flawed here.

Another 10GW of each of wind and solar is a drop in the ocean.  Only a week or so ago the wind generation was down to 50MW (according to gridwatch).  No solar in the dead of night and minimal in the depths of winter.

Supplying summer midday demand with wind and/or solar might be one thing but reducing carbon intensity throughout the year would not occur by closing down all the nuclear plants in short order.  Need a lot more storage and a lot more renewable generation for that to occur.  But letís get on with it and climb out of the fossil burning and nuclear options.

Tidal generation would be better - at least it is predictable and covers most of 24 hours.  Lagoons or flow, it matters not.  Cost of storage needs to be included for solar and wind generation, of course.  But a zero CO2 intensity is still a good target to aim for.  Then close down the nuclear facilities as and when possible.
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brackwell
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« Reply #31 on: June 15, 2018, 08:37:59 AM »

At the moment wind is "having its cake and eating it".  Due to the merit order effect wind and solar generation gets a kind of priority which at present levels is fair enough. However as the RE increases its gets paid for curtailment, has as just happened.  This in my opinion is a burden on the consumer and needs to stop immediately. This curtailment needs to be considered as part of the investment decision.  Investment will then continue until a balance point is reached where CF (capacity factor) is balanced against cost as an investment decision/calculation.  The tech guys will then develop ideas to use the excess to increase financial returns such as colocating wind with sun with storage with gas production etc.

Who knows how far down the line this development would go coupled with changing demand times,smart meters,EV charging and V2G etc.

Ken
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azps
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« Reply #32 on: June 15, 2018, 09:24:12 AM »

Another 10GW of each of wind and solar is a drop in the ocean. 

It's about 3.5 - 4GW of clean power on average. That's about 10% of electricity supply. Our nuclear fleet is aging, in decline and shutting down. Over the next few years, it's going to average about 10% anyway.

Quote
Only a week or so ago the wind generation was down to 50MW (according to gridwatch).  No solar in the dead of night and minimal in the depths of winter.

Yes, they're exogenously variable. And, the costs of managing that variability are now very low, as we've seen in the capacity auctions and the frequency-reserve auctions. And new transmission capacity is relatively cheap too.

Quote
Tidal generation would be better - at least it is predictable and covers most of 24 hours.  Lagoons or flow, it matters not.

Oh, it really does matter: lagoons do little or nothing for flood protection. If we build lagoons, and then have to build barrages outside them, it's going to be an deeply inefficient use of resources.

Quote
But a zero CO2 intensity is still a good target to aim for.  Then close down the nuclear facilities as and when possible.

The UK's old nuclear plants will be closed long, long before that. While the UK continues with its nuclear vanity projects, that sends a strong negative signal to renewables investors that they can and will get sidelined whenever the government feels like it, in favour of more expensive nuclear projects. And that negative signal means that investors require higher returns, pushing up prices. That's why Germany's signal to investors in 1999 that nuclear was being phased out, was so important, and so effective in getting huge amounts of capacity built, and getting lots of investment in wind & PV manufacturing.

On brackwell's point re renewables getting paid to generate and to curtail: well, yes - all other generators are eligible for those payments too, so I don't see any reason why renewables should be excluded from them. Wind, when generating, can be an amazingly fast responder to changing demand - that's a valuable service, and it should get paid to provide it, just as gas plants do. A lot of the time wind can do it better than gas can, too. We're just starting on a big transition. Existing markets certainly aren't fit for purpose any more. There will be a short period when we over-pay for ancillary services, in order to stimulate the innovation needed (and given how low the prices are in those markets, the over-payment isn't onerous at all). That's a good thing, as long as it's only a temporary circumstance. The sort of negative prices that Germany and Denmark see are a good thing: they're stimulating innovation in demand response, storage, and a bunch of other things. We'll know when there's been enough innovation, because the negative prices will shrink away, as long as we've restructured the markets to enable the demand-side to express itself fully.

I've no wish to gloss over the exogenous variability of wind and sun. They're big and interesting challenges. We know we've got solutions for them. We don't know what the most cost-effective mix(es) of solutions look like yet, and to a very large extent, we're only going to discover that by asking the market. We do at least have very strong evidence that the market will fully solve this, and that we will as a country and a planet be able to afford it. I realise that this won't please those people who see it as a jigsaw puzzle, and who need to see the lid to get the full picture before starting to solve the puzzle. But radical transitions just aren't like that. Instead, we have an idea of many of the shapes in the picture, and many of the colours. But there isn't a single picture to aim for - there's a range of possible good-enough pictures, and we have the resources to make useful extra pieces as we go along. Some innovations we don't have time for - it's senseless to put things on hold until fusion or magically cheap small modular nukes appear - the time from early prototype to commercial-scale roll-out is too long. Other innovations are happening in good time - the huge cost reductions in offshore wind, in battery storage, in PV, in smart grids, electric vehicles, and so on, bears that out.

A zero-carbon target is important. Let's remember it's not the only challenge we've got. We are still resource-constrained, which means that we cannot ignore the economics. And right now, the economics favours early closure of nuclear plants. I agree with M that the cost savings are hidden, while the expenditure is not, and that that is a challenge for politicians. It does require politicians to be a lot franker with the public about the actual trade-offs. The challenge is that about half the public are insisting that they can have their cake and eat it, and they've been led to believe that by politicians who know full well that those sort of fairy stories end in bitter tears.
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pdf27
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« Reply #33 on: June 15, 2018, 01:00:24 PM »

I always struggle with the rationale behind the "social cost of nuclear" calculations, mostly because the statistical basis for them is extremely weak.
  • For radiation protection modelling, we use the linear no-threshold model: this assumes that cumulative radiation exposure is what matters, and that risk scales linearly with exposure - reduce the exposure by a factor of 10 and you also reduce the chance of cancer by the same factor. We have two good data points where people were exposed to known, high levels of radiation and tracked through their lives to give excess cancer rates - Hiroshima and Nagasaki. There is strong reason to suspect that this curve is not in fact linear but that high dose rates are much more damaging than low dose rates - but nobody really knows what shape this curve is: there are even still people who (rather implausibly IMHO)think that low dose rate radiation is actually protective against cancer.
  • A large fraction of the cost of an accident is related to how the cleanup is done, and that is largely a matter of what is acceptable to the public rather than being based on a measurable and acceptable level of risk. The Fukushima evacuation, for instance, almost certainly killed more people than it saved: the radiation levels across most of the zone are no worse than the naturally occurring levels in Cornwall, and we know that forcing elderly and vulnerable people to leave their homes will cause an increased rate of mortality. At the same time it would have been utterly acceptable to the Japanese public not to evacuate everybody in a zone where there was a measurable increase in the background radiation level, whether or not this would be good for them. The key point here is that the size of the cleanup/evacuation zone (and hence of the economic impact) will depend enormously on the public reaction to any accident - and this will be heavily influenced by both the prevailing culture in a country and the way the authorities handle the aftermath. The Japanese government and TEPCO both handled things poorly here, and due to the legacy of Hiroshima and Nagasaki I would expect the Japanese public to be more than usually sensitive to any release of nuclear material.
  • Location & weather conditions at the time of the accident are both hugely influential as well, for instance an accident at Bradwell when the wind is coming from the North-East would be very different to one where it is coming from the West. The only real way to approach this is to do a huge number of Monte Carlo simulations to predict the probability of each scenario, for each nuclear site and accident combination. That's a rather large task, so it would be very tempting just to take a particular site and study it alone, then extrapolate for other sites around the world.
The Leipzig study is at https://www.versicherungsforen.net/portal/media/forschung/studienundumfragen/versicherungsprmiefrkkw/20111006_NPP_Insurance_Study_Versicherungsforen.pdf - I'm struggling a bit with some of the terminology, but if I'm understanding it correctly the calculations were done based around the solvency requirements for insurance companies which require a 99.5% probability of making a profit where enormous risks are being insured.
The biggest variation seems to be how long after the premiums start to be paid that the insurance company must be able to pay out the loss insured for - compound interest has a massive effect, and all nuclear scenarios are extremely unlikely (1 accident per million years being a common standard to design to). If you want the insurers to be able to pay out after 10 years, the premium in the study was calculated at ~500 Billion Euros per year per power plant: however, from year 11 onwards the insurers have got sufficient money to cover any accident (indeed, because it is invested they are making a profit on it) and any further premiums are pure profit too. Because the study was limited to Germany, they seem not to have investigated the alternative way of lumping all the power plants worldwide into a single risk pot, which minimises the impact of compound interest and gives you a halfway decent chance of understanding what the social cost of nuclear power actually is, because as far as I can tell the 140-6730/MWh is the amount that a commercial insurer would have to charge to be able to assume full liability in a nuclear accident, which given the restrictions they operate under is not at all the same thing.
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knighty
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« Reply #34 on: June 15, 2018, 02:44:01 PM »

As I've recently commented I understand the need for more interconnectors but have a different view when it might mean having one as little as 0.6km from our house!!!!!!!

why?

I don't understand the nimby mentality
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M
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« Reply #35 on: June 15, 2018, 03:44:02 PM »

A zero-carbon target is important. Let's remember it's not the only challenge we've got. We are still resource-constrained, which means that we cannot ignore the economics. And right now, the economics favours early closure of nuclear plants. I agree with M that the cost savings are hidden, while the expenditure is not, and that that is a challenge for politicians. It does require politicians to be a lot franker with the public about the actual trade-offs. The challenge is that about half the public are insisting that they can have their cake and eat it, and they've been led to believe that by politicians who know full well that those sort of fairy stories end in bitter tears.

As you say we don't yet know what to aim for, but here's some more good news that 60% leccy from RE (actually just wind and PV) is looking fine:

Solar and wind could provide 60% of UK power without jeopardising reliability, study finds

I'm sure I remember being told that 20% was an upper limit, then 30%, when we hit 20%, then 40%, 50% etc. The naysayer limit always seems to be just above where we are, whilst investigations seem to suggest ever higher potential.
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Just call me Mart.     Cardiff: 5.58kWp PV - (3.58kWp SE3500 + 2kWp SE2200 WNW)
dimengineer
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« Reply #36 on: June 15, 2018, 08:30:34 PM »

As I've recently commented I understand the need for more interconnectors but have a different view when it might mean having one as little as 0.6km from our house!!!!!!!

why?

I don't understand the nimby mentality

|There's Nimby and theres' Nimby. 600m is actually quite a way away. I have a tube line 600m away in suburbia - could be 100km. I never see it or hear it. But if it were just across the bucolic valley in full sight, I might think different
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djs63
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« Reply #37 on: June 15, 2018, 08:45:46 PM »

Pdf27
I get your analysis with no buts or ifs. However, working with radioisotopes in a medical situation I used to believe that particles emitted might collide with a DNA or protein molecule and cause a change but given that there is lots of space between molecules the chances are small, but, the more particles emitted the greater the chance of a damaging collision. I thus tried to minimise exposure.

However, how you scale that hypothesis up to the world of nuclear reactors and drums of radioactive waste and thereby calculate the risk of damage to people and the environment is a mystery to me.

So
I would go back to the basic assumption that damage arises by chance collisions inside body cells and that more radiation means more risk.  And the energy in the particle....... linux

Wind, PV and hydro sound good to me.
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6 Kw Proven wind turbine, 15 Navitron evacuated solar hot water tube array and 1.8 Kw PV, grid connected (SMA inverters) and GSHP supplying radiators and UFH. Wood burning stove (Esse 300) and oil fired Rayburn. Rainwater harvesting 4000 litre tank underground. Nissan Leaf
pdf27
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« Reply #38 on: June 15, 2018, 09:51:11 PM »

Pdf27
I get your analysis with no buts or ifs. However, working with radioisotopes in a medical situation I used to believe that particles emitted might collide with a DNA or protein molecule and cause a change but given that there is lots of space between molecules the chances are small, but, the more particles emitted the greater the chance of a damaging collision. I thus tried to minimise exposure.
The ratio between exposure rate and a harmful mutation is the critical one, and while it is well understood at high dose rates the effect at low dose rates is not at all understood. There is some evidence that the body is able to repair damage below a certain rate pretty well - for example, smokers who are exposed to radon have a vastly higher rate of lung cancer than you would expect from evaluating the two effects individually. It's not perfect so all the radiation protection principles still apply (dose rate to be ALARP, etc.) but the distinction is pretty important when calculating population effects from a major accident.

However, how you scale that hypothesis up to the world of nuclear reactors and drums of radioactive waste and thereby calculate the risk of damage to people and the environment is a mystery to me.
They've taken the simplest of all possible models - worked out what the cancer rate is for say 500 mSv exposure in one hit, then said that 500 people getting a 1mSv dose or 1 person with a 500 mSv dose will have the same number of cancers as a result. Work out the population exposure from any hypothetical accident, and you get your cancer rate. Problem is, what limited evidence we have (it being massively unethical to do human studies!) suggest that this particular model (the "linear no threshold" or LNT model) really doesn't work at low dose rates. It's prudent to use it for radiation protection purposes because everybody is confident that low doses aren't more dangerous per mSv than high doses and so the public will be protected as a result, but it means the estimates are likely to be inaccurate.

Wind, PV and hydro sound good to me.
With appropriate regulation, yes - I get rather irked when some people seem to think that they're automatically safe. PV and Wind involve working at height which is inherently dangerous, and PV in particular is often installed in a domestic roof setting where installers may skimp on scaffolding, fall restraint, etc. to save money. Dams hold a huge amount of stored energy and need to be treated with particular care - the deadliest power generation related accident by some margin was the Banqiao dam collapse which officially killed 26,000 people from flooding and 145,000 through subsequent epidemics and famine. They can all be done safely - but attention to detail and rigorous risk analysis is required to ensure that appropriate protection measures are in place. For what it's worth I would be keen for all three to be expanded as fast as practicable in the UK, but I'm not blind to the fact that they have flaws too.
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brackwell
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« Reply #39 on: June 16, 2018, 09:19:16 AM »

RE curtailment payments.

I am led to believe that this only applies to wind generators.  In both wind and FF generators get paid the grid price for the not produced leccy (also bearing in mind this could be a very small amount in times of oversupply) but only in the case of wind is there an extra curtailment payment.  This curtailment payment might have been justified in the early days of wind but not know?

Ken
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azps
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« Reply #40 on: June 25, 2018, 06:52:16 AM »

RE curtailment payments.

I am led to believe that this only applies to wind generators.  In both wind and FF generators get paid the grid price for the not produced leccy (also bearing in mind this could be a very small amount in times of oversupply) but only in the case of wind is there an extra curtailment payment.  This curtailment payment might have been justified in the early days of wind but not know?

No, all technology types are able to bid into the balancing market to get those curtailment payments. Wind is not special at all in that regard. And how else can the system operator ensure that demand and supply match, and that no transmission links are overwhelmed, given the market structure? They buy regulation services. Anyone can sell them. It's just that wind happens to be particularly good at selling this one kind of regulation service: ramping down very quickly at very short notice.

Part of the problem has been that a lot of wind was built in Scotland, but there's not much consumption up there, meaning lots has to be moved South. And, due to one thing and another, building new north-south transmission capacity happened very slowly. So there used to be lots of times when there'd be too much power generated up North, and no way of moving enough of it down South, so there was a valuable market for ramping down generation in Scotland.

Now that the Western HVDC Link is operating, the need for curtailment of Scottish wind is expected to drop a lot.
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