79 replies to this topic

[Shortpoet-GTD]

Besoeker, on 20 November 2013 - 12:41 PM, said:

Both in the same hemisphere.
How would you do it between hemispheres?

Rather than arguing points with members, how about offering solutions for a change-or perhaps links?
Shooting down everyone on every post comes across as argumentative and it's not furthering the facts
or discussion.
Are you a member just to argue?

[Besoeker]

Shortpoet-GTD, on 22 November 2013 - 04:29 AM, said:

Rather than arguing points with members, how about offering solutions for a change-or perhaps links?
Shooting down everyone on every post comes across as argumentative and it's not furthering the facts
or discussion.
Are you a member just to argue?

A little unfair, I think......but, well, never mind.

I'm sure you already know what my day job is.
As I've mentioned a few times, in my professional life I have been instrumental in implementing systems that have saved and continue to save industrial scale chunks of energy. Next week I have a meeting with a customer to discuss a new bit of kit they are buying from us.
It will, based on my calculations, save just under 16,000kWh per day. And that's just one example.

I've written, presented, and co-authored a few papers on this stuff and I do energy effieiency audits. I don't often write about this. It can be taken the wrong way. But it's all part of what I do for a living. So you might wonder what what I'm getting at, why I'm setting this out?

Not self agrandisement I assure you - I'm far too far past my sell by date for that. Just background to explain that, after over four decades I just might have learned a bit about energy and energy efficiency transmission and other stuff.

On that basis, I rather think it would be a bit remiss of me not to comment on the practicalities of transmission over the distances being suggested. What are your thoughts on the matter?

[Mullerstainz]

For more information about the project of linking Africa and Europe with energy infrastructure go on Desertec.org. The fellows of DESERTEC are making practical the idea of linking Africa and Europe. Applying the same process to South America and North America is easier ‘cause there isn't a sea between them. DESERTEC is the practical way. It’s just a matter of applying the same process between different places.

[Besoeker]

Mullerstainz, on 22 November 2013 - 06:45 AM, said:

For more information about the project of linking Africa and Europe with energy infrastructure go on Desertec.org. The fellows of DESERTEC are making practical the idea of linking Africa and Europe. Applying the same process to South America and North America is easier ‘cause there isn't a sea between them. DESERTEC is the practical way. It’s just a matter of applying the same process between different places.

Voltage drop and distance is the issue that has to be addressed.
Bigger conductors or intermediate booster stations stations could help. It means the energy you get at the receiving end is less and perhaps a lot less than at the sending end.

Desertec I've known about for some years now.
North Africa  and southern Europe are not so far apart. You can stand in Tarifa and see the Atlas mountains.

For northern Europe, it then gets a bit more difficult.It isn't the sea that's a limitation - the cross-channel HVDC link has been in service for a long time and routinely operates at close to its 2GW capacity,

I don't know how to explain this very well.
Every km run results in losses. More km, more losses.
That's why I question the feasibility of connecting two hemispheres.

[eds]

How much energy is DESERTEC going to sell in Germany?

Germany, the 5th largest economy in the world in PPP terms and
. . . Europe's largest, with "Energiewende" producing:
. . . . . . EFFICIENT,
. . . . . . DISTRIBUTED,
. . . . . . SELF-CONSUMED energy,(Zero losses per Zero Kilometer)

The major electricity generators account for just
. . . 7% of the renewable energy, and
. . . 93% comes from farmers, households, communities and small business,
. . . that now makes up nearly 1/4 of the county’s  electricity production.

Now you see Germany starting to look at battery storage,
. . . storage is very different from Central energy,
. . . storage is very important.

Attached Files

•  Distributed.jpg   59.65K   0 downloads

[Besoeker]

eds, on 22 November 2013 - 11:52 AM, said:

How much energy is DESERTEC going to sell in Germany?

The major electricity generators account for just
. . . 7% of the renewable energy, and
. . . 93% comes from farmers, households, communities and small business,
. . . that now makes up nearly 1/4 of the county’s  electricity production.

Other sources suggest that renewables, including hydro, accounts for about 16%.
But, even taking your 25%, the other 75% has to be sourced from somewhere.
DESERTEC, if/when it gets up and running, overcomes the distance issue, might be a potential source of some of that 75%.

[Shortpoet-GTD]

Off topic note for a minute- you have the expertise besoeker; all I am suggesting is you share some of your knowledge
on these boards.
You may be greener in the long run than many on the boards but you don't sound that way sometimes.
Excuse my harsh words but please post some links or share your knowledge base with us-ok?

Back to topic. Thanks

[Besoeker]

Shortpoet-GTD, on 22 November 2013 - 03:39 PM, said:

Off topic note for a minute- you have the expertise besoeker; all I am suggesting is you share some of your knowledge
on these boards.
You may be greener in the long run than many on the boards but you don't sound that way sometimes.
Excuse my harsh words but please post some links or share your knowledge base with us-ok?

I thought I had.
From further up this page
"It will, based on my calculations, save just under 16,000kWh per day. And that's just one example."

I suppose I could include some detail but.......well here's an excerpt from something I did for a UK university presentation a while back.

"It is common practice to consider the cost of ownership over the projected life of a drive and for this the drive operating efficiency needs to be taken into account.
As with harmonics, the efficiency of the converter is largely dependent on the converter rating so it might be expected that losses would be around one fifth of an equivalent static inverter or similar drive and this proves to be the case. For the SILK, the losses are generally under 1% of the drive rating. For an inverter the losses, including a unit transformer, would be about 4%. Even if there is no unit transformer there will be losses somewhere in the distribution network via a step-down transformer unless the inverter takes power directly from the incoming supply voltage."

I'm sure very boring if you're not into these things and the difference of 4% to 1% may not seem a lot but when it is based on units of a few thousand kW.............

Enough!

My background is in industrial applications. Energy savings are taken very seriously. Perhaps none more so than in the water industry. In this country, and elsewhere in the world, water companies want to control costs. Capital costs are pretty much a one-shot deal amortised over typically twenty years here. The water comes out of the sky (or sometimes not) but the water company has no control over that.

One thing they can control is operating costs.Variable speed operation of pumps is one very effective way of doing that. Drop the speed by 10% and that reduces the power required by 30%. These are big numbers.. Really, really big numbers.

London (water) ring main, operated by Thames Water, has fifteen variable speed drives, each around 800kW so 12,000kW total. And that hardly scratches the surface of the Thames Water operation.

That's where it's at. At least a lot of it. So, if you want to make a BIG difference, lobby your water companies to go down the variable speed drives route - and point them in my direction..........

You asked for a link.
Here's one.

pumps

I confess that I haven't read it but stuff like that comes into my work email with mind numbing frequency.

Moving on.....

Something we touched on a while back at the other end of the power scale, and also something you gave me a bit of a hard time over, here is a little exchange from another forum, an electrical one, where I also post. It relates to, gasp, gasp, gasp to vampire power..........

"I agree. I think the term vampire for such things is greatly overused.
I post on another forum (shock horror, I know!) and vampire loads are routinely trotted out as our nemesis.
As always, it needs perspective. I don't switch off our main television. I ought to be hung, drawn, and quartered for that totally inexcusable behaviour.

My appeal to the executioner is simple and based on simple fact.
In the standby mode, the television uses 0.9W. My tiny mobile phone charger doesn't get above ambient as far as I can tell with my sensitive temperature monitoring devices AKA fingers. . Stick your finger on a 0.5W resistor running at full chat - better still, don't - unless you wish to permanently alter your fingerprint.

Common sense, though not as common as it's purported to be, ought to indicate that if something gets hot it gets hot and dissipates heat. If it doesn't, it doesn't."


"True, but keep in mind that the area through which the heat is shed has a big effect on the temperature that you feel.

If the charger has 100 times the surface area, then it will have 1/100th of the temperature rise."

"Yes. Of course, size matters. That's why I mentioned that the charger was tiny, you see.

It possibly won't surprise you that, with me being in the field I'm in, I routinely have to do calculations for thermal dissipation from electrical enclosures.
I've developed programmes for surface heat and force air cooling.
For something the size of the charger, a small fraction of a watt would produce an appreciable temperature difference. I can detect none."

[Shortpoet-GTD]

Numbers-percentages, kilowatt indicators; whatever -may sound boring but you'd be surprised how many
viewers love that kind of post.
Don't want to call them nerds, but they enjoy reading that; so please don't hesitate
to post stuff like that.
If it furthers the cause to green, it's worth  it; boring or not.   

Back to topic (and thanks besoeker)

[E3 wise]

I would agrr with Shortpoet, this was a nice posting on the affects variable speeds can have, along with both the mention of harmonics and inverters.  The saving of energy on an industrial scale is hugely important and seeing you talk about that was quite informative..you contributed new information, well done.

[Besoeker]

Thanks Short

Maybe you have a better idea now of what my day job involves.
I've made a few mentions of energy savings and efficiencies. the big driver for the water companies was reducing energy costs. So, not entirely altruistic nor particularly motivation to be green. But It helps the environment all the same.

FYI, this is the sort of thing we make. This one is for a fairly big pump.

[eds]

OUTSTANDING!   
I have no idea what i'm looking at,
. . . but it is impressive.
I just don't have the specialised knowledge to understand it, and
. . . that's just what we need,
People with specialised knowledge, willing to care and share their viewpoints,
. . . who while we may not always agree with each other on how to do things,
. . . are willing to hear each other out and contribute their expertize.

[Besoeker]

eds, on 23 November 2013 - 07:32 AM, said:

OUTSTANDING!   
I have no idea what i'm looking at,
. . . but it is impressive.
I just don't have the specialised knowledge to understand it, and
. . . that's just what we need,
People with specialised knowledge, willing to care and share their viewpoints,
. . . who while we may not always agree with each other on how to do things,
. . . are willing to hear each other out and contribute their expertize.

Thank you Eds.
Appreciate the mature viewpoint. Yes, we can agree to disagree.

A little explanation of the picture.
It's what is termed a variable frequency inverter (VFI).
Supply frequency is fixed (60Hz for you guys) and any motor connected to that will run at fixed speed.
In some cases, it is desirable to alter the speed of a motor and that's where the VFI comes in.

On centrifugal pump applications, that can save a lot of energy. As I noted above, dropping the speed by 10% reduces the energy consumed by about 30%. The unit shown is rated at 315kW at full poower. It's easy to see that it has the potential to take a big chunk out of energy consumption.

[E3 wise]

Ed’s if I am correct what you are looking at are electrical control units used for combining very large motors that are put together in series to pump very large volumes of water.  I bet Besoeker could find a picture to post to give you an example. I think it could be very educational to the forum.

The motors are three phase alternating current using high voltages (240, 440, 660,720 or up here in the US), by combining two or more huge motors together in series you are able not only pump more but also balance the electricity needed.  (Like the gas pedal on your car to balance current, torque, and load to achieve and hold a specific speed.) That way the motor does not waste energy running at full capacity all the time.

I think this area of electrical usage is very important because the technology is used in industrial water pumping and movement, HVAC (large buildings), and a myriad of other motor usage areas on the commercial and industrial scale.  Maximizing their electrical efficiency saves us all a lot of energy and reduces emissions from fossil fuel sources.  
Electrical control units are designed specifically to save energy by balancing the amount of electricity coming in to the amount of actual work needing to be done, thereby allowing speed control to reduce usage when not needed. Thereby achieving greater efficiency and folks that is one of the cutting edge areas of energy today, maximizing the most you can out of our business,production, commercial and industrial electrical usage.

[Besoeker]

E3 wise, on 23 November 2013 - 10:45 AM, said:

Ed’s if I am correct what you are looking at are electrical control units used for combining very large motors that are put together in series to pump very large volumes of water.  I bet Besoeker could find a picture to post to give you an example. I think it could be very educational to the forum.

The panel is for driving a fairly large motor depending on your perspective. But just one motor rated at 315kW. (about 420hp). The panel, one of seven on that particular project, went overseas - USA if I remember correctly - and subsequently exported from there. So, I don't know the head and flow characteristics of the pumps.on each of the drives.

E3 wise, on 23 November 2013 - 10:45 AM, said:

The motors are three phase alternating current using high voltages (240, 440, 660,720 or up here in the US)

Three phase, yes, But 400V in this case.Still technically classed as low voltage though.
We do also make medium voltage (3,300V) and high voltage (11,000V) variable speed drives but they are usually much higher power.

E3 wise, on 23 November 2013 - 10:45 AM, said:

by combining two or more huge motors together in series you are able not only pump more but also balance the electricity needed.

Not in series in this case. Three phase motors are not generally designed to be operated in series. As I said, in the case related to the pic, the motor is 400V 3ph. Pretty standard for European countries.

E3 wise, on 23 November 2013 - 10:45 AM, said:

(Like the gas pedal on your car to balance current, torque, and load to achieve and hold a specific speed.) That way the motor does not waste energy running at full capacity all the time.

Yes. you make the motor run at the speed just required to get the desired flow or sometimes pressure.
Usually there is some control system, SCADA or PLC based that sends a signal to the VSD to get the right flow. Actual flow is measured and compared with desired flow and the speed adjusted accordingly to maintain that flow. Feedback you see.

E3 wise, on 23 November 2013 - 10:45 AM, said:

I think this area of electrical usage is very important because the technology is used in industrial water pumping and movement, HVAC (large buildings), and a myriad of other motor usage areas on the commercial and industrial scale.  Maximizing their electrical efficiency saves us all a lot of energy and reduces emissions from fossil fuel sources.  
Electrical control units are designed specifically to save energy by balancing the amount of electricity coming in to the amount of actual work needing to be done, thereby allowing speed control to reduce usage when not needed. Thereby achieving greater efficiency and folks that is one of the cutting edge areas of energy today, maximizing the most you can out of our business,production, commercial and industrial electrical usage.

Yes, pretty much. Adjusting the speed is very much more energy efficient than than using valves or dampers for pumps and fans which was generally the method used before variable speed drives became main stream.

[E3 wise]

Thank you so much for the clarifications.

[Shortpoet-GTD]

Now we're talking!
The nerds (oops-techies) will love it. Post more of that!

[Besoeker]

E3 wise, on 23 November 2013 - 06:52 AM, said:

I would agrr with Shortpoet, this was a nice posting on the affects variable speeds can have, along with both the mention of harmonics and inverters.  The saving of energy on an industrial scale is hugely important and seeing you talk about that was quite informative..you contributed new information, well done.

Thank you kindly.

My professional life has mostly been based around variable speed drives.
They have been around in different forms for over 100 years.
Mainly for processes like paper and steel mills that needed to have speed control for operational needs rather than efficiency.
That's really how I got into the field. Thrown in at the deep end in my first job. Sent out on site  to fix problems on kit that dated, sometimes from the 1930s. Sink or swim. Some very elegant electromechanical systems that I'd never even heard of. But swim I did. Maybe when you are young, as I was then, you are undaunted. When you get older, perhaps you think to much, imagine scenarios.....stuff

Things move on . The introduction of semiconductors with ever increased power handling capabilities was a bit of a game changer. All that happened within my lifetime.
In the 1960s and 1970s, we were making DC variable speed drives.
By the 1980s, there were semiconductors that made control of AC motors a practical proposition and that's when we really got into energy savings for pump applications with variable frequency inverters.
Existing fixed speed applications could be converted. It was a rather specialised field but energy savings was an attractive proposition for customers.

Better semiconductors have followed on and it has now become a pretty mature technology.

[Besoeker]

Shortpoet-GTD, on 23 November 2013 - 02:45 PM, said:

Now we're talking!
The nerds (oops-techies) will love it. Post more of that!

I don't mind being called a nerd - or much else for that matter....:)
I do what I do. Engineering.
But also mathematics to - much of engineering is applied mathematics. Understand the problem. Formulate the mathematical equations. Solve them. Interpret the result. Very important last step that.

But just for some fun, I was discussing mathematics in another forum. Art or science.?
MA in my case. But, in no way, am I an artist.

Anyway, I had generated a couple of images.



This isn't a doodle. It is mathematically generated. And it serves no practical purpose.
Does that make it art?

And the same formula producing a stylised butterfly...



Better than a pile of bricks....

[synodbio]

Good post! To make things better and heal our world we need desperately to understand how we’ve made things worse, even with good intentions, and this means that we need to bring the psychological dimension into our discussions about the environmental crisis.