By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale July 23rd

Some big tools

All Topics | Latest Posts

Search for:  in Thread Title in  
vintage engineer16/01/2019 19:24:24
avatar
142 forum posts

**LINK**

Rockingdodge16/01/2019 19:50:12
avatar
97 forum posts
20 photos

Who's going to build a model then? working of course devil

Phil Whitley17/01/2019 19:23:56
851 forum posts
115 photos

Amazing machine, but something very dodgy with the maths.230 megawatts will power about 19320 households at the average Uk usage of 12kWhr per day 230MW is 230,000 watts /230,000 households= 1kw each!!

roy entwistle17/01/2019 19:32:25
1005 forum posts

Phil

Surely 230,000 watts is 230 kw not mega watts

Roy thinking

not done it yet17/01/2019 22:37:27
3144 forum posts
11 photos
Posted by Phil Whitley on 17/01/2019 19:23:56:

Amazing machine, but something very dodgy with the maths.230 megawatts will power about 19320 households at the average Uk usage of 12kWhr per day 230MW is 230,000 watts /230,000 households= 1kw each!!

Do you use 1kW of power all day long, every day? That would be 24kWh per day? We most certainly don’t!

There is a difference between kW and kWh. One is power, the other is energy.smiley

Phil Whitley18/01/2019 19:04:20
851 forum posts
115 photos

Roy Entwhistle, 230 MegaWatts is 230,000KW divided by 230,000 householdsis, as I said, 1KW for each household, so what happens when the favourite tv serial ends, and one third of the consumers get up and put a 2kw kettle on? Energy usage is tied to time of day and generated power has to be matched as exactly as possible with demand from the grid, you cannot push more in than the demand, and if you cannot meet demand the results are disaster! The average daily usage iin the UK is 12 KWh, in the USA 24Kwh, but it will not be used at an even rate throughout the day, and at times demand will rise much above the available 1KW per household. This is why generators are kept running and on stand by, to be switched in when demand suddenly rises. Having been an electrical engineer since the seventies, I fully understand the difference between KW and KWhrs, but you must generate enough power to cover the huge peaks in demand when most people come home from work, and put on the kettle, the washer, the tumble dryer, and then start to cook the evening meal, when this happens, 1kw per household will be woefully inadequate!

Edited By Phil Whitley on 18/01/2019 19:08:57

Edited By Phil Whitley on 18/01/2019 19:10:00

SillyOldDuffer18/01/2019 20:19:03
4521 forum posts
971 photos
Posted by Phil Whitley on 18/01/2019 19:04:20:

... but you must generate enough power to cover the huge peaks in demand when most people come home from work, and put on the kettle, the washer, the tumble dryer, and then start to cook the evening meal, when this happens, 1kw per household will be woefully inadequate!

...

Not sure that's entirely accurate for two reasons:

  • Home usage of electricity tends to be balanced by commercial and industrial usage - when they're at home workers aren't consuming power at work and vice versa. A system sized to satisfy commerce and industry should be OK meeting residential demands - most of it occurs off-peak.
  • One advantage of Smart Meters is their potential to manage demand by encouraging consumer behaviours. Customers could be encouraged on-the-fly not to use electricity when it's expensive during peaks by charging more for it, and encouraged to consume power when there's a surplus, by selling it cheap. In other words, avoid boiling a kettle when the meter says it is charging you top-whack! Smart meters could also selectively shed load intelligently if the system was over-stressed. A visible-cost arrangement might work well in cooperation with electric cars. Your meter could be set to charge the car preferentially at cheap rates, and to credit you if the grid uses your car's battery capacity to smooth out peaks. On average I'd expect millions of cars to be simultaneously connected to the grid because many vehicles spend most of their time parked up.

Dave

mgnbuk18/01/2019 20:26:57
507 forum posts
10 photos

"Its the largest milling machine in the world" - 'cept it isn't - its a vertical borer, not a milling machine.

Neither is the centre lathe or the floor borer - an old Asquith.

Impressive project, though.

Nigel B

roy entwistle18/01/2019 20:36:32
1005 forum posts

Phil What you just said is not what you originally wrote

Roy

Edited By roy entwistle on 18/01/2019 20:57:37

Phil Whitley18/01/2019 20:43:11
851 forum posts
115 photos

SOD, commercial usage has dropped through the floor since the advent of intelligent drive systems, led lighting and the demise of many if not all our major load producing industries. Smart meteres are not for the benefit of consumers, they are there for the supply companies to make extra profits!! why do you think they have put so much money into development and installation? It would be insane for private companies, who bill us for the power to make it easier for us to use less of it! There is never a surplus of power, load must be matched to demand always, and it is very expensive to have generators running on stand by. The daily requirements of the grid are known to a very fine tolerance, and the major job of the generators is to match exactly as possible, supply to demand. Remember, the companies that send you your bill and will be installing your smart meter do not generate any power, they just buy in bulk from the generators, and sell to us at retail prices. http://www.gridwatch.templar.co.uk/. "cheap rate" used to be called "off peak" and was a result of the generators realising that it was more economical to run steam turbines on line than keep them running on stand by, so sell the electricity in the off peak hours, but how? thats why storage heaters were invented, and they were marketed until there was literally no off peak hours left, the problem was, as the consumers soon found out, in most households with patchy insulation they are absolutely THE most expensive and inneficient way of heating your house, and they have been scrapped by the millions! Electric cars are very expensive, and there is, as yet no second hand market developing, because of the cost of batteries! they will not reach the mass market for a long time yet, and this may create a Cuba like situation where, although no new petrol or diesel cars are being produced, older cars are being kept going virtually indefinitely.

Edited By Phil Whitley on 18/01/2019 20:46:46

Phil Whitley18/01/2019 20:56:17
851 forum posts
115 photos

Sorry Roy, yer right, I missed a I missed the K off, 230MW is 230,000KW, and the rest is correct! If it is any consolation, I get called Whiteley all the time, I have got used to it! I assure you no discourtesy was meant!

roy entwistle18/01/2019 20:59:24
1005 forum posts

Phil Apology accepted

Roy

SillyOldDuffer19/01/2019 10:58:29
4521 forum posts
971 photos
Posted by Phil Whitley on 18/01/2019 20:43:11:

SOD, commercial usage has dropped through the floor since the advent of intelligent drive systems, led lighting and the demise of many if not all our major load producing industries. Smart meteres are not for the benefit of consumers, they are there for the supply companies to make extra profits!! ...

...

Possibly there's some confusion of ideas here, maybe because the industry is changing. What was truth 20 years ago in the supply industry is now much less solid, and the future less certain.

  • I don't think you can say 'commercial usage has dropped through the floor since the advent of intelligent drive systems, led lighting and the demise of many if not all our major load producing industries.' AND claim ' The daily requirements of the grid are known to a very fine tolerance' in the same argument.
  • What are Smart Meters for? Your suggestion they are a means of increasing profits cannot be right because they are being installed to meet government targets. They are an energy policy measure focussed on likely future developments. When fossil fuels were the cheapest way of making electricity there was no point in Smart Meters, but energy policy has to consider what happens when fossil fuels get much more expensive. Using Smart Meters to alter customer behaviours is one way of managing power if future supply is less reliable.
  • You also say 'There is never a surplus of power, load must be matched to demand always, and it is very expensive to have generators running on stand by.' Again, that was mostly correct 20 years ago. What it misses is the arrival of sustainable energy from solar and wind farms. The problem with these is they don't respond to demand. Instead, they often make power available to the grid when no-one wants it. Some of it does useful work by allowing turbines to burn less fuel, some of it can be stored - but that's expensive. Another way of using it is by pricing it so that people find ways of using it.

At the back of future eneg is that burning coal and oil cannot go on indefinitely because they are starting to run out. Even if environmental damage and risk of climate change are ignored, we have to do something else.

Electric vehicles are a possible way of exploiting sustainable energy - many owners could choose when they recharge and the batteries in electric cars could be useful storage.

It's very difficult to predict the future. I might be completely wrong but I'm expecting the world to be rather different in 20 years time. Energy will be significantly more expensive, with knock-on effects through-out the way people live and behave. Motoring is likely to become relatively more expensive than it is today, I think private car ownership will drop. Change is nothing new - before 1840 all transport was animal or wind powered. Then steam locomotion enabled massive change (but London was full of horses in 1918). Over the next 40 years horse transport was gradually pushed out by electricity and internal combustion, but wasn't until about 1955 that private car ownership became popular. The world of cheap energy as we understand it has been running for about 60 years and it cannot be sustained for ever.

Very likely we will see Cuba-style cars on UK roads for a few years - people who can't afford to buy new electric, who struggle on while fuel prices rise. They will disappear as petrol gets more expensive and harder to find - not many of the existing petrol stations will stay open once demand falls. I don't see any of this happening overnight, short of someone triggering a recession. That's unlikely unless someone upsets the apple cart by starting a major political, constitutional and economic crisis where no-one knows what's going to happen next...

That's the way I see energy going, but I might be completely wrong. Although change is certain, it's hard to predict. What worked in the past cannot be relied on forever. In future the world will be different, where possible I think it best to gather facts, shoot all the sacred cows, and then try and swim with the tide.

Dave

Ady119/01/2019 11:40:38
avatar
3463 forum posts
513 photos

I read one article a while back now

Peak time for domestic electricity usage was no longer winter but the school summer holidays

Millions of kids with up to a KW of desktop computer playing World of War etc etc up to 20 hours a day

I've walked dogs for 35 years now and on a lovely summers day in the school holidays the park is empty.

In my youth the parks were stuffed with us all playing football, Celtic even won the European Cup with 11 Scottish football players

Colin Whittaker21/01/2019 01:51:41
98 forum posts
12 photos

Right at the end the destination for these turbines was revealed ...

I wish this manufacturing company good luck in getting paid by any customer in Venezuela.

Phil Whitley21/01/2019 19:52:04
851 forum posts
115 photos

Dave SOD, I am an avid reader of Electrical Review (first editor was Michael Faraday though unfortunately I dont have any issues from that time!), and have been since the seventies, when it was much more of an interesting magazine than the 90% advertising content it sports today. The most interesting page by far is "Gossage" insider news from the electrical industry, and it is an eye opener. there are many problems in the electrical supply industry, but one of the major ones is the unprecedented drop in demand, which has fallen 15% in the last ten years, and due to the ongoing conversion of all street lighting, shop lighting,traffic signals etc etc to LED demand is continuing to fall. Consider a time when all UK lighting is LED, which is about 90% more efficient than incandescent, and you are looking at 90% less demand for lighting.

The reason Hitachi have just pulled out of building two nuclear stations is the fact that, even at the garunteed price per MWh the government have promised them (approx double the rate today) they are unwilling to make such a huge investment on a falling demand market without garuntees the government was not willing to give them. A cynical viewpoint would be that the very reason they were invited to bid in the first place was that the government knew demand would fall to a point where nuclear power was so expensive that it simply was not a viable business model, and therefore needed someone else to carry the risk. When Tony Benn, as energy minister made his announcment that nuclear energy would be so cheap it would not be worth metering, and you would pay for it at an annual "rate" like water, he was not in possesion of the true costs of nuclear power stations, the only thing cheap about them is the fuel, the costs of building, maintaining, repairing, and eventual dismantling are collosal in comparison with other methods of turning water into steam for turbines which are, at best about 33% efficient. Remember also that when it comes to decomissioning, the taxpayer picks up the tab!

Hinkley is a case in point, there have been several different consortiums, most of whom have pulled out, leaving EDF holding the baby. Electricite De France is heavily backed by the french government, who have refused any more money to build this type of power station until and if EDF complete one and actually make it work. At present, the one they have built in France ( which, of the 5 they are building is supposedly nearest completion) has not produced a watt, is massively over budget, and (I think) 7 years behind schedule. In fact, no one from EDF will give a time when it will be completed, or will start testing! (Gossage, a few months ago, you can read gossage online at https://www.electricalreview.co.uk/features/10545-gossagegossip)

If you go to www.gridwatch.templar.co.uk you will see what is generating our power 24/7/365, updated every 5 minutes. Oil is now only used in standby stations, and coal usage is very low. Almost 50% of demand is met by combined cycle gas turbines, which are approaching 50% efficient, and use exhausted heat from the gas turbine to make steam for an additional turbine, hence the efficiency. Nuclear, at very best output, with all reactors operating at full output can only supply about 24% of peak demand and it is a red letter day when this happens. Even if Hinkley is ever finished and works, which is by no means certain ( the whole idea should be scrapped!) it will not provide any EXTRA energy, because it will be replacing existing units, which are long past their sell by dates (really) and will be shut down.

 

The problems with nuclear go on and on because of the golden deal they have with the government which goes back to the fifties. The electricity supply companies, whoever they may be, are tied to buying ALL the output from nuclear stations before they can use other forms of generation This is the only way nuclear can ever be commercially viable. As I have said before, you cannot push extra power into the grid, output from generators has to be matched as exactly as possible to demand at all times, so many times a day, some generation will have to be shut down, and because of the "golden deal" what is shut down is wind and solar. I am sure you have driven past turbines on breezy days and seen them not running, well this is the reason! What is needed is a reversal of this situation, so that the base load is picked up by wind and solar, and the top up comes from other forms of generation. This of course is not going to happen till (perhaps we have almost got there?) the nuclear plants are worn out (they are already well past their design life) and too expensive to repair or replace.

Please check out the Grid status link, at the moment wind is providing 10.03 Gigawatts, whilst nuclear is providing 5.77 gigawatts coal is providing 3.5GW, and combined cycle gas turbine is providing 22.6GW and oil no longer features at all. We are not running out of fossil fuels, despite the horror stories of the sixties and seventies, Britian has huge coal deposits which are virtually unmined today, and new oil and gas discoveries are being made all the time, indeed some areas of the scientific world are beginning to look at if these substances are indeed "fossil fuels" entirely, or by products of the huge amount of underground volcanic activity which cases them to rise up from the core to be trapped under impervious rock layers

Edited By Phil Whitley on 21/01/2019 20:35:08

Phil Whitley21/01/2019 19:52:50
851 forum posts
115 photos

The power generation industry needs an overhaul, maybe renationalised it might work better, maybe not, but under the old electricity boards (My Dad worked for the YEB as an engineer for 22 years) there were only two tariffs, Domestic and Commercial, today there are so many that it is impossible to know whether you are getting a good deal, which like mobile phone contracts, which they mirror, is exactly what is intended.

on smart metering, there is one thing for sure, the meter can sense the difference between resistive and inductive load, and without getting into power factor, which is a very complex subject, the generators have to generate more power to satisfy an inductive load, than they do for a resistive one, and it looks like they are going to begin charging for this extra, or at the very least these meters give them that ability. That the public have purposely been told that the smart meter will save them money is a barefaced lie, I will repeat, no one in the business of selling anything will spend many millions on developing and installing a device that does nothing other than reduce their sales. The cat however is slowly crawling out of the bag, and if the public get fully aware of what is going on, they may never be able to fully implement smart meter use to their advantage. If it was all about saving energy, why not make their installation compulsory? I am quite convinced that this was going to be implemented in a way that the public would not notice a gradual increase in charges for inductive loads. Ofgem has been singularly unsuccesful in making the power companies toe the line on many issues, so all I can say is, "watch this space"

Phil.!

Tim Stevens21/01/2019 20:10:15
avatar
1048 forum posts

Phil says: If it was all about saving energy, why not make their installation compulsory?

I thought that was exactly what the UK Govt have done, (but being the Govt, they are not pressing the point.)

Tim

Phil Whitley21/01/2019 20:46:55
851 forum posts
115 photos

No Tim, you can refuse them, and many are!

Phil Whitley21/01/2019 20:55:25
851 forum posts
115 photos

Colin, well maybe 1KW would be enough for a venezuelan consumer, but without getting into KvA, most UK consumers, whose incoming cutout is fused at 100amps have almost 21KW available. which sounds like a lot till you consider that some electric showers are 10KW!

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
Advertise With Us
Eccentric Engineering
TRANSWAVE Converters
Ausee.com.au
Warco
Eccentric July 5 2018
Meridienne Sept 2019
ChesterUK
Allendale Electronics
emcomachinetools
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest