The energy solution for South Africa is DC power.

[Wasabee!]

I think Eskom should buy lots of rechargeable AA batteries for extra power. OP you are right. DC FTW!

 

[Seriously]

Good, your endless fallacies were getting tiresome.

I am sure that is a phrase that many members in PD and on this forum tells you every day in so much words. There is just no ointment for idiocy?

 

[Seriously]

So roughly I measured 220AC@0.018amps input for a output of 5.27V@0.350 resistive load. The regulation in this unit was terrifying with this NNB China unit to say the least, If I load 0.59A then output voltage drop to 2.76V, which is probably due to the lack of digital control.

So on the DC-DC unit with slightly better regulation, If I load 0.65A then output voltage drop to 4.1V, I measured 12DC@0.2amps input for a output of 5.08V@0.330 resistive load.

I have done some measurements on a Samsung charger. Internally it looks more robust and seems to have a digital controller.

I measured 220AC@0.01amps input for a output of 4.76V@0.33amps resistive load. Much better.

 

[Swa]

2.2W in order to deliver 1.57W. Very efficient

 

[Swa]

Oh boy. Wasn't going to reply any more but I just can't let a few people believe the BS you spew here.

You Seriously lost the plot and missed the boat again.

Using the 220VAC Inverter you retain all the existing high power appliances and conveniences. Think induction stoves/hobs, heaters, PC power supplies, etc. All modern efficient appliances for their use and needs.

Using the modern 220VAC consumer electronics devices which use SMPS for regulating the required low power is more economical and effective than before. Think...Cell phone chargers 150mA@220VAC input with 1Amp@5VDC output. Very few devices still use transformers and linear regulator power supplies. Only cheap China junk. See picture below.

You lost the plot and missed the boat again. Using the inverter together with the other transformers to make it compatible with existing low power appliances has 80% efficiency at best. I hate to break it to you but most power supplies are still linear and not smps even if you want to believe them to be cheap China junk.

In the above pic the 220AV get rectified in 350VDC and then produce the regulated 5VDC via a high frequency switched mosfet at high efficiency. There is no linear regulators.

In the picture the lower unit converts 12VDC to 5VDC using a similar switching mode principle.

YOU CAN USE THREE OF THE 220VAC DEVICES AS OPPOSED TO ONLY ONE OF THE 12VDC DEVICES FOR THE SAME TOTAL LOAD SUPPLY CURRENT

What you fail to understand is the load losses due to copper resistance and thus the required heavy duty large diameter copper wire required to use all the devices in a home environment will be far more costly than simply using a 220V inverter with its claimed "efficiency losses". Effective high voltage potential energy is then available and many consumer devices can be used all at the same time on standard 2.5mm2 copper wiring. No need for modifications or expensive supply wiring. There are only a few plug circuits with trip switch breakers in a home electrical DB feeding a each to few power circuits. Most people use multi plug extensions to enable them to use more devices at such plug points at any one time. Changing these feeds to 12V DC will come at a large expense requiring more circuits with thicker copper wire and bigger more robust circuit breakers or tripping electronics to service the same amount of consumer goods. There are just no solutions to overcome this reality.

No, what you fail to understand is that the 12VDC unit is 6.6 times more efficient at using power so the AC unit would drain your source much quicker. That's without the inverter to supply the AC which reduces the efficiency even more. For the umpteenth time high power devices are an irrelevant straw man as they were never claimed to be running on the low voltage supply.

Your whole premise is that people should cut out their conveniences and appliances /snip

That is not my premise but your straw man. Also still a pretty big ego you have there that can claim to speak on behalf of everyone.

 

[Seriously]

2.2W in order to deliver 1.57W. Very efficient

Then again I can power 20 * more cellphones on the same wire all at the same time for zero cable losses where with 12VDC I will loose 16W or 20% due to heat in the cable.

Solar energy is free so the "efficiency" is a fallacy you cling on consistently. The installation is the main issue concerning costs not the efficiency thus again by saving on copper wire costs and thus civils/building modifications during installation there would be more funds available to add an additional 20% capacity to compensate. The other key point is that you still retain all the appliances and consumer electronics with no additional costs for special DC PC power supplies and appliances that costs a fortune and limits the use regards to total wattage possible on the supply source cables. Remember your 12VDC kettle that would take 45 minutes to boil your water for a cuppa and the 10mm2 copper wire required to feed your recommended 12VDC PC power supply?

 

[Seriously]

Oh boy. Wasn't going to reply any more but I just can't let a few people believe the BS you spew here.


You lost the plot and missed the boat again. Using the inverter together with the other transformers to make it compatible with existing low power appliances has 80% efficiency at best. I hate to break it to you but most power supplies are still linear and not smps even if you want to believe them to be cheap China junk.


No, what you fail to understand is that the 12VDC unit is 6.6 times more efficient at using power so the AC unit would drain your source much quicker. That's without the inverter to supply the AC which reduces the efficiency even more. For the umpteenth time high power devices are an irrelevant straw man as they were never claimed to be running on the low voltage supply.


That is not my premise but your straw man. Also still a pretty big ego you have there that can claim to speak on behalf of everyone.

What a lot of hogwash BS gibberish again. Solar is free so why be concerned for the 20% less efficiency? A few more batteries and panel capacity will overcome that problem. No need to spend a fortune on a copper bus bar and civils through the home so you can use more than one consumer items at any time. People just want to move over to solar not redesign the wheel.

 

[Swa]

Then again I can power 20 * more cellphones on the same wire all at the same time for zero cable losses where with 12VDC I will loose 16W or 20% due to heat in the cable.

No you can't because as we've seen converting from AC to DC has a big efficiency loss and then there's the loss of the inverter. So now we much search for super efficient inverters and smps modules which are compatible with the devices in order to just match the same efficiency of a direct DC system.

Solar energy is free so the "efficiency" is a fallacy you cling on consistently. The installation is the main issue concerning costs not the efficiency thus again by saving on copper wire costs and thus civils/building modifications during installation there would be more funds available to add an additional 20% capacity to compensate. The other key point is that you still retain all the appliances and consumer electronics with no additional costs for special DC PC power supplies and appliances that costs a fortune and limits the use regards to total wattage possible on the supply source cables.

You are the one clinging to a fallacy. Solar energy has costs associated with it and with the main costs for a storage system being the batteries you want it to be as efficient as possible. For a system where the cost of batteries is R50k a 80% efficiency means over budgeting with R10k. The first step in going solar is to reduce usage by as much as possible. Many people going solar also go gas for cooking and heating purposes in order to reduce the installation size so there goes your straw man of having to forgo modern conveniences which I showed to be an invalid argument to begin with.

What a lot of hogwash BS gibberish again. Solar is free so why be concerned for the 20% less efficiency? A few more batteries and panel capacity will overcome that problem. No need to spend a fortune on a copper bus bar and civils through the home so you can use more than one consumer items at any time. People just want to move over to solar not redesign the wheel.

For the umpteenth time again special wiring isn't needed so you can stop with that retarded logic that I already laid to rest. With the cost of storage efficiency is everything in a solar setup. It isn't free.

 

[Seriously]

No you can't because as we've seen converting from AC to DC has a big efficiency loss and then there's the loss of the inverter. So now we much search for super efficient inverters and smps modules which are compatible with the devices in order to just match the same efficiency of a direct DC system.


You are the one clinging to a fallacy. Solar energy has costs associated with it and with the main costs for a storage system being the batteries you want it to be as efficient as possible. For a system where the cost of batteries is R50k a 80% efficiency means over budgeting with R10k. The first step in going solar is to reduce usage by as much as possible. Many people going solar also go gas for cooking and heating purposes in order to reduce the installation size so there goes your straw man of having to forgo modern conveniences which I showed to be an invalid argument to begin with.


For the umpteenth time again special wiring isn't needed so you can stop with that retarded logic that I already laid to rest. With the cost of storage efficiency is everything in a solar setup. It isn't free.

Again a lot of hogwash.

Explain how can we feed 12VDC for 20 meters to my 360W PC using (your example) and specifically reference to the fact that no special wiring or conduit is required.

As for the so called extra storage capacity the simple fact that you will be saving a lot of energy costs over many years make your argument weak. The fact that many are going solar or have done it already and thus have the experience proves its viable. Yet you argued with those experienced members, How many installations have you done? Give me one example where anyone else have done the 12VDC solution you preach apart from the OP with some limited lighting?

 

[Swa]

Again a lot of hogwash.

Explain how can we feed 12VDC for 20 meters to my 360W PC using (your example) and specifically reference to the fact that no special wiring or conduit is required.

As for the so called extra storage capacity the simple fact that you will be saving a lot of energy costs over many years make your argument weak. The fact that many are going solar or have done it already and thus have the experience proves its viable. Yet you argued with those experienced members, How many installations have you done? Give me one example where anyone else have done the 12VDC solution you preach apart from the OP with some limited lighting?

Still continuing with your straw men. Yes many have gone solar. That doesn't mean your idea of a system is the best. It's a weak red herring to suggest that a system providing "free" energy should not be efficient and cut down on costs as much as possible.

 

[Seriously]

Still continuing with your straw men. Yes many have gone solar. That doesn't mean your idea of a system is the best. It's a weak red herring to suggest that a system providing "free" energy should not be efficient and cut down on costs as much as possible.

The PC was examples you injected and when you were caught out you started with your PD type circular arguments.

So I gather you do not have the answer to the PC and thus many other consumer devices and as such just spew your strawmen BS over and over. Many have told you they do not want to forego their consumer conveniences. Many are turning to solar and NONE what I have read proclaims installing a DC bus in the home. So again please give examples and back it up by calculations instead of spewing a total lot of BS.

Again:

How many installations have you done
How many 12VDC installation projects can you link to.
Explain how I can feed 12VDC to my 360W special and very expensive PC power supply I want to buy based on your recommendation.
Explain the double amps DC of 30Amps over a 2.5 mm2 copper wire.

Explain why a 12VDC system from solar is best and how it can be achieved

 

[Swa]

The PC was examples you injected and when you were caught out you started with your PD type circular arguments.

So I gather you do not have the answer to the PC and thus many other consumer devices and as such just spew your strawmen BS over and over. Many have told you they do not want to forego their consumer conveniences. Many are turning to solar and NONE what I have read proclaims installing a DC bus in the home. So again please give examples and back it up by calculations instead of spewing a total lot of BS.

Again:

How many installations have you done
How many 12VDC installation projects can you link to.
Explain how I can feed 12VDC to my 360W special and very expensive PC power supply I want to buy based on your recommendation.
Explain the double amps DC of 30Amps over a 2.5 mm2 copper wire.

The high power devices on a low voltage source is a straw man YOU injected. We have told you over and over that powering low power devices from 12V doesn't mean forgoing any conveniences but you keep harping on this non point of yours.

 

[Seriously]

The high power devices on a low voltage source is a straw man YOU injected. We have told you over and over that powering low power devices from 12V doesn't mean forgoing any conveniences but you keep harping on this non point of yours.

When member specifically asked you if they should rig their devices in the meantime until your futuristic 12VDc appliances arrive you answered that particular question with another BS argument, It's not something I injected it was something others asked you to explain YOU NEVER DID!

360Watt for a PC is not a lot and it's not a high power device, Also I am using YOUR own example you gave and you still mentioned there is a plan for it, so please explain as requested!

PS: Anything you may have forgotten you said I can look up and repost, I will do it for you.

 

[Seriously]

@Swa please just use your engineering and design skills and answer the list of questions with calculations and facts. No more BS circular arguments. We have homes to rewire!

For the umpteenth time again special wiring isn't needed so you can stop with that retarded logic

Explain this as you specifically stated that we should change to the two prong square plugs or cigarette lighter sockets as in cars?. So again do you you still maintain that we can pull 30Amps (your example) over the existing 2.5mm2 standard copper wires?

BTW please advise what circuit breakers we should use in the DB or are we turning to fuses or just connect straight and leave it till the home burns down?

 

[Swa]

When member specifically asked you if they should rig their devices in the meantime until your futuristic 12VDc appliances arrive you answered that particular question with another BS argument, It's not something I injected it was something others asked you to explain YOU NEVER DID!

360Watt for a PC is not a lot and it's not a high power device, Also I am using YOUR own example you gave and you still mentioned there is a plan for it, so please explain as requested!

PS: Anything you may have forgotten you said I can look up and repost, I will do it for you.

The only BS argument was yours. It was specifically said that most low power devices are already compatible with 12V. Iow they are current and not futuristic as you claim.

I would very much like for you to look up things. While you are at it you can also look up context. We will see people like lsheed_cn using principles like the skin effect to claim that DC requires solid core cable. Then there is your article on power transmission which you tried to use to prove that DC in a home isn't viable when the article itself says it isn't applicable to DC in the home. You claimed that 600V from solar panels are worth the extra costs of equipment and special wiring based on an argument from authority where calculations showed the little extra efficiency to not be worth the extra expense. You also then change your argument against special wiring when it comes to high power DC devices which wasn't even part of the argument and just your own straw man. After arguing for efficiency in a solar system you are now arguing against it.

@Swa please just use your engineering and design skills and answer the list of questions with calculations and facts. No more BS circular arguments. We have homes to rewire!

Come back when you have solid arguments instead of straw men and stopped with your flip flop arguments.

 

[Seriously]

The only BS argument was yours. It was specifically said that most low power devices are already compatible with 12V. Iow they are current and not futuristic as you claim.

I would very much like for you to look up things. While you are at it you can also look up context. We will see people like lsheed_cn using principles like the skin effect to claim that DC requires solid core cable. Then there is your article on power transmission which you tried to use to prove that DC in a home isn't viable when the article itself says it isn't applicable to DC in the home. You claimed that 600V from solar panels are worth the extra costs of equipment and special wiring based on an argument from authority where calculations showed the little extra efficiency to not be worth the extra expense. You also then change your argument against special wiring when it comes to high power DC devices which wasn't even part of the argument and just your own straw man. After arguing for efficiency in a solar system you are now arguing against it.


Come back when you have solid arguments instead of straw men and stopped with your flip flop arguments.

Again I am using your own examples and arguments you brought up and you yourself failed to justify and still do. Safe to say then you know Fall as practically everyone else in this thread already told you.

Now we wait for your solutions and calculations to prove us wrong. Go for it I dare you. Start with the 12VDC@360Watt@30Amps capacity on 2.5mm2 copper wire, Your example no one elses!

Oh, you forgot conveniently to mention your [-]misunderstanding[/-]lie about Isheed_cn's 600VDC application I see.

 

[Swa]

Again I am using your own examples and arguments you brought up and you yourself failed to justify and still do. Safe to say then you know Fall as practically everyone else in this thread already told you.

Now we wait for your solutions and calculations to prove us wrong. Go for it I dare you. Start with the 12VDC@360Watt@30Amps capacity on 2.5mm2 copper wire, Your example no one elses!

Again, as I'm continually showing you and you fail to acknowledge the examples you keep bringing up are your own straw men. So instead of clinging to things that have already been answered over and over answer these questions:
Why are you arguing against efficiency when you first argued paying for a slight increase in efficiency?
Why are you against special wiring when you argued for it in order to get a slight increase in efficiency?
Why did you use an article which states it isn't applicable to DC in a home as an argument against it?
What about all the other inaccuracies in your posts I keep pointing out?

Until you can answer satisfactorily why you keep flip flopping your arguments we have no reason to believe you know anything about what you are talking about.

 

[Seriously]

Sigh. Still no concrete evidence or information! just a lot of circular arguments and more BS.

See below the posts before I or you got involved in this thread, you responded to these members with lots of mental gibberish and no facts. It suits you to now claim I brought it up in the discussion.

More to come keep it up!

Lets save 30% on the cost of installing solar at home because its a DC system... but have to spend 300% more on appliances and stuff.

Just imagine the cost of copper cabling for DC allpications !!!
2kw kettle running on 240V AC will draw 8.3 Amp, so a 1,5mm copper cable is fine.
The same kettle running on 12V DC will draw 166.7 Amp, so a 50mm copper cable will be required. Cabling your house will cost more than the house itself

DC isn't going to happen as the wiring costs are too high, as has been pointed out already in the thread.
Copper costs money. DC requires more cable than AC does.

May be possible to run lighting on DC, as you can buy 12v or 24v LED lighting fairly easily (well, at least I can!), and at 5w a bulb, its not going to need thick wire, as the current draw is low. I just ordered a bunch of bulbs for my accountant who's running a 12v system in fact. 12v systems also need more calculations for voltage drop / cable length than ac systems do. For every few meters of cable, you drop a volt, so you end up needing to run things at higher voltages to cater for the voltage drop.

For anything resembling a moderate current draw, you can also forget DC - eg washing machine, kettle, heaters, toaster, oven, geyser etc etc. Note why your car battery cable is so thick, and look at the price of copper wire, then see why 240v ac makes more sense.

DC makes sense for some things, but not that many as you think.

As for your solar idea -

I have solar panels on my roof. I don't run low voltage DC from the panels, as the cabling would be insane. Instead I run high voltage DC @ 600v / 8a to an inverter (which is 98.8% efficient at the curve for the datasheet, not 80% as some have suggested in thread), which then generates A/C.
DC from panels will work for a few panels - eg a smaller system, but nothing really larger.

Ok, so now we must custom make all the little appliances we use at home, and jury rig solutions for the appliances we can't?

Sorry, but no.

 

[Swa]

Sigh. Still no concrete evidence or information! just a lot of circular arguments and more BS.

See below the posts before I or you got involved in this thread, you responded to these members with lots of mental gibberish and no facts. It suits you to now claim I brought it up in the discussion.

More to come keep it up!

Exactly, and all of these misconceptions were responded to and shown inaccurate but you keep digging them up as if they are valid. You haven't actually quoted anything you claimed you were going to quote.

So let's turn to some questions to see if your support is validly placed:
Do you agree with lsheed that DC requires solid core cabling?
Do you agree with him that DC requires more cabling?
Do you agree that it would be necessary to rig most of the appliances we use or custom make them?

Careful how you answer them as they will determine whether or not you know anything.

 

[itareanlnotani]

Do you agree with lsheed that DC requires solid core cabling?

High voltage DC does require solid core cabling.
AC cabling doesn't due to skin effect.
Please feel free to completely misinterpret that again, as you have done so many times.

Do you agree with him that DC requires more cabling?

Any moderate size current draw requires more cabling (substantially more) if running on your 12v DC suggestion.
If you run at higher voltages eg 240v you could reuse standard size cables, although you'd still need solid core cable vs the more typical multistrand as in point #1.

Do you agree that it would be necessary to rig most of the appliances we use or custom make them?

If you're running at higher voltage DC (which would really be necessary) then all the devices will still need to have equipment inside to bring the voltage down to whatever levels they need to run at. Given that 3/4 of the world has standardized on 240v or 120v AC its going to be a hard battle to change that. You also lose all your benefits of changing in the first place.


DC has a few area's where it make sense - high voltage transmission is one (as you don't need to sync DC up as there are no phases to sync). For house use, less so.


You've been debunked many times.