Posts by Wilco 1
197 posts • joined Thursday 24th September 2009 08:48 GMT
Re: Like for like comparison required
A9-based Calxeda server chips have been available for a while. But for a rough comparison with modern ARM cores, Tegra 4 scores 4582 on Octane, so a Cortex-A15 is quite a bit faster than Centerton on single-threaded code. At 8.5W the current Centerton has no chance of winning the power efficiency battle.
Re: x86 uses microcode instructions...
The x86 complexity certainly wastes power, which is more noticeable in low power designs and less so in high performance cores. This shows the relative sizes of ARM and x86 cores: http://chip-architect.com/news/2013_core_sizes_768.jpg. Jaguar achieves similar performance as Cortex-A15 but needs twice the area. Atom needs a lot more area in order to achieve low voltage / low power operation, and it's huge die size explains why we won't see quad core versions until 22nm. So yes there is definitely a big cost to x86 - few companies have succeeded making competitive designs. With ARM it is far easier to design a high-end CPU.
He simply meant that Denver will be faster than ARM's fastest 64-bit core, Cortex-A57. So it might be 4-way OoO like AMCC's 64-bit ARM, ie. seriously quick given that A57 beats A15 by a good margin.
Re: False Prophet
There is no "other 60%". Capacity factor means you get on average 40% of the max capacity throughout a year. On average. Ie. it's not 100% for 40% of the days and 0% for 60% of the days but far more averaged. Obviously there are low-wind days across the UK, but in those cases you simply turn CCGT stations a bit higher. These are required anyway in order to follow the daily demand (nuclear and coal can't do this). Wind power simply reduces the amount of CCGT required (and to a lesser extent coal).
You can clearly see this happening in the last few days: http://www.gridwatch.templar.co.uk/index.php
See how the monthly nuclear/coal/ccgt graph shows much lower CCGT/Coal is from April 13 onwards? Next check out what wind power did in those days. Also remember the recent El-Reg scare story how we almost ran out of gas? Now you know why we didn't...
Re: Peak coal
Talking about recent cooling: check
AGW must be false because of the recent cold weather: check
Conflating weather and climate: check
From http://climate.nasa.gov/key_indicators/
CO2 increasing: check
Land ice melting: check
Sea ice melting: check
Sea level rising: check
Temperature rising: check
Checkmate.
Re: @esskay
Yes, without any subsidies solar PV would become competitive eventually, but it would take much longer that way. If you dislike renewable subsidies, do you also dislike all the oil, gas, coal and nuclear subsidies? The tax payer will be paying countless billions just for the cleanup of the current nuclear generation...
What source of energy can generate cheap and plentiful energy? Certainly not nuclear (not cheap, and we never got the promised "too cheap to meter"). What else? Fusion is still at least 50 years off...
We're going to face increased bills no matter what. Coal, gas, oil are all becoming scarcer and more expensive. You can't blame increased bills on renewable energy when Russia decides to charge twice as much on the gas we use.
Re: False Prophet @ Wilco1
Ledswinger, it's very simple really - wind, solar and nuclear always want to sell all electricity they can produce irrespectively of the market price. If you disagree with that, you simply don't have a clue despite trying to claim to know better. And no, I don't care who you work for. But can you show us some of your publications? Now that would show you know your stuff.
Nuclear is NOT competitive on the grid without subsidy. EDF tries to get a subsidy for 40 years at TWICE the current market rate for Hinkley C. That just says it all.
Re: Renewables can be more than afart in a hurricane.
Yes Germany and Denmark are ahead of the UK. But we're not doing that bad either: wind power generated 10% of the UK demand almost continuously since last Saturday: http://www.gridwatch.templar.co.uk/index.php
Re: False Prophet
You're wrong there, wind power is very reliable (it's unlikely wind is suddenly going to disappear forever is, it?), and quite predictable days and weeks in advance. Yes you cannot 100% guarantee it is windy all the time, but a recent study showed that just placing wind farms all around the UK reduced intermittency significantly.
Interconnects will play an increasing role in the future, and they don't need to be very far either. Connecting to Iceland would open up a large amount of geothermal power, Sweden/Norway/Finland gives you hydro and pumped storage.
Re: False Prophet
Again, in what way does it matter? Building a nuclear power plant costs far more as well. In the end what matters is the cost of the electricity produced. And nuclear costs more than on-shore and is similar with off shore.
Re: Renewable Energy
It's not just the anti-nuclear parties or the NIMBY's, EDF wants twice the market rate for electricity for 40 years for the new nuclear power station Hinkley C. That's a price where even the current government is saying that's a pretty huge subsidy to a private company (especially given wind subsidies last for just 15 years).
Re: @esskay
Renewable technology has become far far cheaper in the last few decades due to increased volume and efficiencies. For example solar PV panels are now just £1/W in the UK! That's becoming cheap enough that they pay for themselves through reduced electricity bills even without any subsidies. And it appears the relentless downward curve has no sign of stopping any soon. Efficiencies are constantly increasing and new discoveries (even thinner films) are being made regularly .
Re: False Prophet
When there isn't much wind obviously production is low. At the moment every GWh produced is consumed immediately, basically no storage is required unless capacity is larger than consumption (and we're a long way off reaching that). For storage solar thermal looks like a better option, but it's not really feasible in the UK climate.
In what way is the number of wind farms vs other plants relevant? Wind farms are typically smaller, even the largest is currently 0.5GW.
Re: False Prophet
Nuclear plants have their downtime as well. It can take many months to refuel for example and during that time you must have a backup.The exact same argument applies to all power generation, all have downtime for expected maintenance and unexpected failures, so you always have to have some kind of backup.
As one adds more windpower to the grid and more interconnects, it becomes more reliable - it is typically always windy somewhere!
Re: False Prophet
No, it's a fact. Wind power costs are coming down, nuclear costs seem to only go up. As I already mentioned, the electricity price EDF wants for nuclear power is twice that of the market rate - higher than on-shore wind power. And if you are going to mention subsidies, what about all the nuclear subsidies, cleanup and storage costs? Nuclear subsidies are an order of magnitude higher and have been going on for many decades.
Wind power and nuclear power are actually fairly similar in the way they work. Both are expensive to build but have low "fuel" costs compared to gas and coal. As a result, both want to sell as much electricity as they can generate. That's logical, if you think it is bizarre for wind power, do you also believe it is bizarre for nuclear?
The fact is that with modern generation, your "merit curve" no longer applies. It only works for fuel based generation.
Re: Renewable Energy
If we aren't already past peak oil, we certainly will be soon. Even shale oil will be a short fad, as each well only lasts a few years. But the real issue people always ignore is the cost of extraction, which is rising fast. Just because we've got large reserves of dirty tar sands in Canada for example doesn't mean it doesn't take huge amounts of gas and electricity to actually extract it (and refine it if you want low-sulfur petrol). So not only does it take a lot more effort to extract it, but in the process of extracting it, we actually waste a significant proportion of it as well. The end result is we get an ever smaller amount of actual useful oil for every barrel of oil extracted. That's typically not shown in the production figures...
Re: False Prophet
Actually nuclear is more expensive than wind power. The £14B new nuclear power station Hinkley C to be built in the UK will produce power that is twice as expensive as the market price, more expensive than on-shore wind power and similar priced as off-shore. Yes, modern, efficient off-shore windfarms like Greater Gabbard (40% capacity factor) are cost competitive with nuclear power. That's the hard reality.
Note wind turbines have been producing over 10% of total UK electricity over the last week: http://www.gridwatch.templar.co.uk/index.php
Re: Keep the fight going...
There has not been any pause in warming. All the measurements show the temperature increase is accelerating in the last 3 decades. Temperatures haven't gone down either - every decade has been consistently warmer than the previous decade. And all other climate indicators show steady loss of land and sea ice, retreating glaciers, increasing sea levels and lower pH levels. See for example: http://climate.nasa.gov/key_indicators/
Re: Keep the fight going...
Look at the actual DATA then, can you seriously claim it has been cooling? All the key climate indicators point to unabated warming at an accelerating speed (and that includes temperature):
http://climate.nasa.gov/key_indicators/
Re: Damn lies, statistics, and the big picture
You're entitled to stick your head in the sand and pretend nothing is going on. But I will laugh at you for being a denialist, especially when the reality turns out to be worse than any predictions so far.
Anyone with any sense of intellect will understand that spewing out an ever increasing amount of pollution is going to do serious long-term harm to our environment and health.
Re: Damn lies, statistics, and the big picture
"Allegedly"? Do you have evidence that proves the extra CO2 is not man-made? Or you simply wish to ignore that fact?
Yes the 30% increase is significant especially since it is unprecedented since at least 500 million years. And according to measurements there is no divergence. Warming trend is accelerating in the last few decades and all of the other climate indicators point to continued melting of ice and increasing sea levels:
http://climate.nasa.gov/key_indicators/
Re: Damn lies, statistics, and the big picture
30% of all CO2 in the atmosphere is man-made. That's less than half we have actually emitted so far (the rest is absorbed by the ocean). Is that not very significant either?
Re: Damn lies, statistics, and the big picture
Nothing is unprecedented if you go back to the start of the Universe. In the early years of earth's existence it didn't support life at all, let alone human life! What matters however is our existence and how much we rely on the current climate and sea levels. So the big picture is this: if our climate is changing it will be a major problem for billions of people - whether it happened 100 millions of years ago as well is irrelevant.
As for our CO2 contribution, humans emit 100 times more CO2 every year than all vulcanoes combined. That should give you an indication of the scale of the issue.
And yes, we are agreed on cutting pollution, improving energy efficiency and using renewable energy.
Re: Lack of Logic Lewis
Most other journalists do appear to have a better integrity and actually report on the science, not distort the science to make it fit within their particular worldview. As several others have already shown, the actual science shows unprecedented melting.
Re: Only quoting the bits where Steig agrees with you?
We'd know 100% sure that man-made global warming is not happening if the global temperature returns to pre-industrial levels, if arctic ice no longer mostly disappears in the summer, if sea levels decrease again, if the retreat of most glaciers is reversed, if ocean heat content decreases - all while CO2 concentration continues to increase.
Now what do you think the chances are this will happen?
Re: Cold winters, Wet summers
Anything that increases IR absorption will increase temperatures, so in that sense any increase is undesirable. As earth heats up, the increased temperature increases outgoing radiation, so at some point the energy radiated from earth matches incoming energy from the Sun and stable state is reached at a higher temperature.
Without feedbacks a doubling of CO2 concentration leads to about 1C increase. With feedbacks it is about 3C.
Re: Melting is unprecedented for at least the last 1000 years.
Funny how you got downvoted there for reporting the actual facts...
Re: This article is lies, isn't it?
How long have you been on here? Of course it is all lies.
The way to read Lewis' climate articles is to invert the meaning of everything he claims. You'll be a lot closer to the truth.
I wonder when we'll see another one of his "there has been no warming in the last 15 years" articles...
Re: Power v Performance
CPU power is quadratic with performance due to voltage/frequency scaling. Assuming all else equal it is also true when you compare high-end CPUs with lower end ones: big, fast, out-of-order CPUs scale non-linearly with increased complexity and need to use leaky transistors to achieve their high frequencies. However it is not necessarily true when comparing between different micro architectures, implementation quality, processes or ISAs (eg. Centerton doesn't look good compared to Calxeda).
In general, if you have a parallelizeable problem, using several slower cores will be more power efficient than one fast core. You can't use too many slow cores though, as the overhead of DRAM, communication etc will eat away the efficiency gained. So the trick is to find the sweet spot where the amount of work done per Watt is maximized. My gut feeling is this is just the start, the next generation of microservers in 2014 will become appealing enough to a wide market.
Re: Build Nuclear
Btw if you believe those motor generator claims or think that cars can run on water then I have an incredable investment opportunity for you. Remember how all that cold fusion was swept under the carpet by big oil corporations? Well I just need some money to continue researching it, and it will make you a billionaire when I find the answer.
Re: Build Nuclear
That just runs on the battery, if you disconnect it, it stops immediately of course. Simples.
Re: back to coal
There is nothing wrong with my calculations, eg. for nuclear I did 10GW capacity * 24 hours in a day * 365 days in a year = 87.6 TWh. Multiply with 0.04 deaths per TWh and you get 3.5 expected deaths per year. It's not that difficult is it? Actual TWh generated is very hard to find, so I was forced to use an estimate, but it gives a good feeling of the numbers.
Yes sure, deaths likely increase as we build more wind farms. But deaths are extremely low to start with, so it's not alarming even if it doubled. There are so many more important things which kill or injure thousands where relatively small investments could make a big difference in reducing deaths and cost to society - I already mentioned RCD's.
Well replacing coal with nuclear would certainly be a better option than keeping coal. Too much of Europe is powered by coal. I don't see how you can have issues with subsidising solar panels or wind power when nuclear/gas/oil subsidies are many times larger. Solar panels are now getting cheap enough that they don't require subsidies for much longer.
Re: Build Nuclear
1. I was using 40% efficiency based on overall efficiency of 36% of UK electricity generation (which is held back by coal). This claims 40-50% for CCGT, so the average is somewhere inbetween depending on demand: http://chp.decc.gov.uk/cms/centralised-electricity-generation/ Ie. your 57% average is way too high. It may be true for newly built CCGT's but it certainly isn't true for existing UK generation.
2. Backup is not required beyond what is already needed anyway to follow the daily demand curve (both demand and wind are followed almost exclusively using CCGT, ie. no CCGT is at 100% continuous capacity, so is already running at lower efficiencies to follow demand). Also you don't require 100% backup on hot standby 100% of the time as wind power is predictable and changes rather slowly - you just need to have enough capacity for windstill days. This capacity may be provided by other sources such as links. So unless you can provide hard evidence of that 10% extra gas, it's just another anti-wind myth.
3. Not sure where you get that 3% but a lot of windfarms are being built close to where most electricity is used. Think London Array. So losses are fairly small and not really different from power stations which need to be on the coast due to requiring huge quanties of cooling water.
So actual saving might be closer to 2.20W gas per 1W of wind assuming 45% average thermal efficiency and 1% losses.
Note that even off-shore wind power is about twice the market rate, so not anywhere near 4-7x. The standby claim is just a myth without evidence, and wind power generated at night is used 100% as we scale down CCGT. Look at this for example: http://www.gridwatch.templar.co.uk/index.php
You never see CCGT going all the way down to zero at night, even when it is very windy like in the last few days. In the summer coal is scaled back as demand is lower anyway. So nothing is dumped.
Re: Gas is far cheaper than electricity
People use gas central heating because it works well and is by far the cheapest option. I don't understand why you keep insisting electric heating is good when in fact it is horribly inefficient compared to a gas boiler or heat pump. I have electric storage heating in my house currently but it's about to be replaced by a combi as that is far cheaper and more efficient, gets rid of the 4 big tanks required and avoids the issue of needing to top up during the day if I use a lot of hot water. Overall the combi will significantly reduce my electricity bill as well as reducing my gas bill due to the increased efficiency.
If you had solar panels then you'd make far more money selling it to the grid and buying gas back for heating rather than heat using electricity. Only if you somehow generated so much electricity that you couldn't sell to the grid then it might make sense to dump it into a storage heater.
In the future we'll move towards heating and hot water using heat pumps. Resistive heating is a waste of energy as it only achieves 100% efficiency.
Re: Gas is far cheaper than electricity
If you use very little gas then don't pay a standing charge. There are lots of deals that don't require you to. But electricity is 2.5-4 times more expensive per kWh, so using electricity for direct heating is the most stupid thing you can do. Electric storage heating is actually a far better option because you can use cheap night electricity at 1/2 to 1/3 of the day rate. It's still 50% more expensive than gas but closer at least.
You're not going to get a 2kW turbine for £600, dream on. The cheapest are around £2000 and that is without the tower, inverter and grid connection. So it'll be at least £4000 before you're on the grid. In any case a small wind turbine on your roof is wasted money even if you can get planning permission - it'll never generate much power. Solar panels would be the way to go. I suggest you do some research on this, as you will lose a lot of money otherwise.
Re: back to coal
I forgot - I completely fail to grasp how you can possibly justify calling wind power "very dangerous, accounting for a great many deaths per year" when you yourself admit it's just 6 deaths per decade. Since when is 0.6 per year a "great many"???
Re: back to coal
Well if you quote deaths per GWh then you can hardly complain when I combine the worldwide numbers (0.04 and 0.15) with actual production in the UK to get expected UK deaths. Nuclear produces more GWh today so also more expected deaths... You can do the math yourself if you like.
As you say most of these are construction accidents. We haven't constructed any nuclear power stations or had a serious accident for decades, so it's no surprise there are 0 actual nuclear deaths in the UK. And 6 wind turbine deaths per decade is extremely low given the large number of turbines we have built. Let's see how Hinkley C changes the statistics.
But it's just crazy to talk about 0.6 deaths per year as being significant. You must be interested in saving lives because that's why you quoted deaths per GWh, right? So we should do something about coal as it would avoid many thousands of deaths in the UK every year.
Looking at the wider picture, even those are insignificant when comparing with deaths due to cars and their dirty exhaust (~1900 deaths due to accidents, ~13000 due to exhaust fumes). And you're proposing we should build nuclear rather than wind just to save 0.6 deaths per year?!? That's just insane. Even fitting RCD's to every home in the UK would save 2 orders of magnitude more lives - every year.
Gas is far cheaper than electricity
For heating gas is far cheaper than electric heating, a really efficient boiler achieves 90+% for central heating and 85% for hot water. I pay 20p/kWh for electricity and 5p for gas including standing charges - that's pretty much the cheapest deal for low usage. So that makes electricity 3.5 times more expensive.
With a really good ground source heat pump (COP > 3.5) one could beat gas, but most won't. If the electricity price is closer to 2 times the gas price then fitting new homes with ground source heat pumps as standard would work. Adding solar panels helps offset any extra electricity used.
For cooking it's much closer, gas is still a little cheaper but electric is about as fast, less dangerous (especially induction) and avoids the extra water and exhaust fumes from burning gas. So overall electric cooking is the better choice, and it's used almost exclusively on the continent.
Re: Too right we are running out of gas.
I found an article on the record: http://www.renewableuk.com/en/news/press-releases.cfm/2013-03-23-record-breaking-day-for-wind
Re: Burning Gas = Electricity
Actually as wind penetration increases, it becomes more rather than less predictable (thousands of turbines give a better "average" than any single turbine does - basic statistics). It does become harder to manage of course - if it is windy too much power may be generated (yes that can be a problem too), and if there is little wind across the UK, you need to find enough capacity of gas/coal and interconnectors to make up for the shortfall.
Re: Sellafield disaster
No there are many tonnes of stuff in that pool, mostly from Magnox reactors. One single reactor generates 25 tonnes of highly radioactive waste containing ~300kg of plutonium per year. Yes, that's a lot more than you thought, right?
So the 1300kg is just the actual plutonium that might be there. Lots of it has now corroded into radioactive mud on the bottom as Magnox reacts with water. And it is going to cost a lot more than $4000/gram just to get it out of there. So I wish you good luck with that JCB!
Btw I guess you didn't know the UK is sitting on a stockpile of 112 tonnes of high grade refined plutonium, worth... absolutely nothing. Nobody wants it, we can't even PAY other countries to take their own plutonium back! We could make a killing on it by selling to North Korea for $4000/g...
Re: Build Nuclear
Well let's look at the actual UK capacity factors then, shall we? Average over 2007-2011 was 27% for wind. Nuclear in the UK achieves 60%. Gas does 62%. Coal in the UK does just 42%. So you need ~50% more wind capacity to match coal and ~120% more to match nuclear/gas assuming no technology improvements (we know new wind and new nuclear do much better, new coal/gas might too).
Yes we agree you need more wind capacity to produce the same output - I have never denied that. But why is that a lousy use of money? New nuclear costs more than new wind per MWh. And ultimately the price per MWh matters more than how many wind turbines one needs to match a power station, right?
Also, you seem to believe, like many, that the capacity factor means that wind turbines are turning only a fraction of the time. In reality wind turbines generate power almost every day of the year, especially if dispersed over a large area. It's just that lower wind speeds result in a lower output. Note that nuclear power stations do actually have extended downtimes (months) where no power is produced. Ie. they cannot reach 100% nameplate capacity over a long period either. 60% capacity factor is pretty bad, does that mean they are doomed too or lousy value for money in your opinion?
The reason I'm impressed with the current wind power results is that the UK just broke the 5GW mark for the first time (a large windfarm came online late 2012) and stayed above 5GW pretty much for 4 full days continuously (and still going strong at 80% capacity today). That has saved a serious amount of gas - the subject of the article.
Re: back to coal
Wrong. Our nuclear capacity is about 10GW, so that's 3.5 deaths per year - or TWICE as many deaths per year than wind power (5GW at 26% capacity). And if we switched ALL our wind to nuclear you'd save... just 1.25 lives per year.
That hardly makes wind power "very dangerous, accounting for a great many deaths per year"... You've got to be a serious spin doctor to make that kind of ridiculous claim.
The fact is gas, oil, coal and even hydro cause about 2 orders of magnitude more deaths. Switching our 20GW of coal to either wind or nuclear would save 2628 lives (or 48700 for Chinese coal) per year. And deaths per GWh doesn't include costs of pollution cleanup, treating illnesses and reduced economic output from work absence. Now that is something that adds up to a measurable quantity.
Re: Build Nuclear
Calm winds will still produce some power with the latest low-speed turbines. Yes it is true you will need CCGT to supplement wind when that happens, but why is that an issue? I don't understand why we would be doomed if we need to burn more gas (or even coal) occasionally. Even using cheap/inefficient OCGT generation for a few total wind still days a year would be fine.
I agree we should diversify renewables far more than we have done so far. That will improve the stability from renewables and further reduce gas/coal usage. The main issue is that most are not as well developed as wind turbines and are often more expensive (the Severn barrier is a huge investment for example, but one we may be forced to do anyway). We should also ensure every new building must have solar PV+thermal panels - the additional cost on a new building is low as panels have become cheap.
About 3.4GW of nuclear power will be decomissioned in the next 6 years, which is replaced by Hinkley C in 2020. It's 2023 before another 5GW goes offline (although extensions to 2030 are expected).
Sellafield disaster
Boris I am not talking about small inaccuracies here but about enormous amounts of radioactive material leaking into our environment. Let's just consider plutonium. For example ~200 kilos of plutonium was dumped in the Irish Sea. Plutonium was found in unfiltered air ducts in various buildings. Around 1300 kilos are thought to be in the leaking open pool "dirty thirty". Nobody actually knows how much radioactive material it contains - radiation around it is so high one cannot get near it for more than a few minutes. It'll cost many billions to clean up just that open air pool. Total cleanup cost of Sellafield is £67.5 Billion: http://www.bbc.co.uk/news/uk-england-cumbria-21298117 Yes, that's several thousand pounds for every tax payer.
If that sounds like a safe and successful way to reprocessing waste to you then I don't know what to say. And you are surprised that many people are against nuclear power? Seriously, read up on the facts before posting ridiculous nonsense about killing the very people who actually care about our environment: http://en.wikipedia.org/wiki/Sellafield
Re: back to coal
Shutting down coal is a good thing, it's by far the most polluting of all forms of electricity generation. It's a shame those costs are currently externalized (deaths and NHS costs due to bad air quality), but when you add pollution controls then you start to see the true cost.
We've just agreed to build more nuclear power stations in the UK. It happens to be as expensive as off-shore wind power: $14 Billion for 3.2GW...
Re: Build Nuclear
Off-shore in the UK achieves 32% capacity factor (Denmark is ahead here with several farms doing 44-52% and a 40% average). Greater Gabbard achieves 40% and costs about £1.3 Billion/GW for the turbines - quite a lot cheaper than a nuclear power station. Turbines last for 20-25 years and existing 20 year old farms are still going, so 30 years seems achieveable. No additional capacity is required as power stations already exist, they just have to work less hard, in particular burn less gas - every Watt produced by a wind turbine saves about 2.5 Watts of gas.
Note the electricity cost of Hinkley C is twice the market rate, on par with off-shore wind power.
Re: Too right we are running out of gas.
I meant 100% of max capacity, it stayed above 5GW for 4 days, a lot more than the 26% average. As far as I can tell it's a new record for the UK. You can see it in these graphs: http://www.gridwatch.templar.co.uk/index.php
