Previous in Forum: Where'd the Wind Go?   Next in Forum: Sustainability Debate – 1
Close
Close
Close
21 comments
Active Contributor

Join Date: Jun 2009
Location: Atlanta
Posts: 15

The Answer to Total Grid Dependence?

06/16/2009 1:35 PM

Is DC Native Voltage UPS the answer to total grid dependence?

Let me start out by saying I'm no math master or whiz kid. I'm just a guy who grew up in the town Edison where built his electric truck factory and one of his two big labs; my grandpa worked for him pulling wire. The apartment we all lived in was just outside the first estate to have electric lighting and fans. It was all DC powered of course. So I know I'm not the first guy to think in these terms. I have a small working DC system in my home today and would very much like to benefit from the experience of others, as every man stands on another man's shoulders. I proffer this concept in open forum before the top engineering experts in all fields because I believe that all the "off the shelf" component parts, with minor modifications, are available to what has to be done to address the looming issues of grid reliability.

First things First, we are not trying to make fire here.. So what's the Big Idea?

All of our 21st century digital electronics work on DC inside the box!

How many a/c to d/c pigtails do you have running 24/7?

We need dual fuel digital electronics to give us www.thepowertochoose.us (site under construction)

Good point about the economies of scale. I'm an A/V engineer working in consumer electronics or communications plant Low Voltage applications since 1967 .

10 years ago I was installing a Fujitsu 42'' "HD" TV , yea right, panel for $12,000 US!

Now you can go to Costco and buy any number of 50" "True HD" for $1,200 and falling!

  • More Questions:

If the Grid is, as some say, only 17% efficient are consumers buying the wrong flat panels?

Fact is, there is as yet no real reasonable break even point, without subsidy, in inverter based Grid tied systems. Am I wrong about this?

All it takes is leadership - Education is key to empowerment, attitudes need to change.

There is a moving price target so long as 19th century norms are accepted such as:

  • Mining interests can bulldoze off a mountain top into streams- to facilitate-
  • Railroads which haul the coal hundreds of miles on trains a mile long -to facilitate-
  • Utilities that then burn it without any of the Carbon ramifications -to facilitate-
  • The Cartels that then push power over thousands of miles of Tesla AC lines -to facilitate-
  • The public that then be literally BURNS what is left in 3-5% efficient 19th century Edison lamps.. IT'S MADNESS!

With 35 million new PC's, all D/C inside the box, running 24/7 are added each year, does anyone think this is sustainable?

I think Edison had it right in short haul power. That is, if we take the personal responsibility to teach our children values and respect through the harvesting of home grown power, by any means and use it on site. Do the math... Every watt made is 8 -12 watts saved in grid dependence. The opposite of freedom is total dependence.

Our Canadian friends can tell you when the lights go out as they often do. Hence the original thread: Cost effective break point of alternative energy is but one of hundreds of jumping in points.Thus far, I've spent under well under $2,000 on what is little more than a 12v RV type system. When the power goes down my PC/communications, security system, and LED lighting will leave me relatively unaffected for days. I've got a back up genny and lots of fire wood, all costs included.

__________________
Everthing changes or becomes extict
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru

Join Date: Jun 2009
Location: South of Minot North Dakota
Posts: 8378
Good Answers: 774
#1

Re: Is DC native voltage UPS the answer to total grid dependence?

06/16/2009 3:05 PM

So where does the DC negative voltage UPS come in at? Did I miss somthing in your rant?

Register to Reply
Active Contributor

Join Date: Jun 2009
Location: Atlanta
Posts: 15
#8
In reply to #1

Re: Is DC native voltage UPS the answer to total grid dependence?

06/16/2009 9:31 PM

That is "Native" voltage. By that I mean in a close to it's original form as is practice.

I have laid out a concept in detail. Do you have any input

Thanx

__________________
Everthing changes or becomes extict
Register to Reply
Active Contributor

Join Date: Jun 2009
Location: Atlanta
Posts: 15
#12
In reply to #1

Re: Is DC native voltage UPS the answer to total grid dependence?

06/17/2009 3:38 PM

Presently I have 7 15 watt solar panels a good charge controller and 1 80AH AGM battery. w/ Fuses on each side. I get about 7 amps in peak hours on the charge side.

I have multiple LED lights and a half dozen DC fans.

There are lots of ways to harvest power available ..

Please take a moment to read what I have written in detail.

Thanx

__________________
Everthing changes or becomes extict
Register to Reply
3
Power-User

Join Date: Jan 2009
Posts: 187
Good Answers: 9
#2

Re: Is DC native voltage UPS the answer to total grid dependence?

06/16/2009 3:40 PM

It is far more efficient to convert voltages using AC than DC. PC power supplies typically convert incoming low frequency AC into DC, then convert it to high frequency AC because transformers can be smaller and more efficient at high frequencies. The transformers in the power supply then produce the several voltage levels needed by the PC circuits. These voltages are then rectified and filtered to produce DC. Similarly, you would still need to convert voltages for different applications.

Motors are typically more efficient at higher voltages. Since motors (appliances) are the biggest energy users in a typical household, it would be expensive and inefficient to install step-up inverters for all of them, but it would likewise be inefficient to run low-voltage high-power motors.

Nor would there be any advantage to increasing the frequency of the AC line in order to skip the first conversion step in a switching power supply. Power transmission systems use low frequencies because transmission losses increase with frequency. Some even use DC, which is then used to run DC/AC motor generator sets. In these cases, the loss in the MG set is less than the AC-related transmission loss. It's all a trade-off on equipment cost versus efficiency.

The greatest loss is in the conversion of thermal energy to mechanical energy at the power plant. That may be where the "17%" number comes from. I would expect that modern systems are somewhat better than that; it is possible to approach 50% with a high-temperature nuclear reactor. The better quality photovoltaic panels presently have a conversion efficiency between 10%-20%. Hydropower is probably the most efficient source, but its availability is limited.

Most people do not want to invest in two completely separate househol electrical systems (DC low-volt and AC). Since AC power generally has a much higher user availability than "alternative energy" sources, the most economical solution in most cases is to install AC and then use inverters or generators to supply backup power if such is considered necessary.

The point concerning stand-by power consumption in electronics is a good one. We pay a significant price for the convenience of not having to flip a mechanical power switch on our electronics and have the entertainment device come on to the last setting used when it was turned off. Transformers used for battery chargers, radios, telephones, etc. all waste power even when there is no load. If people would put those on a switchable power strip and turn it off when the devices are not needed, they could save enough to pay for the strip in a year or two.

The biggest payoff (for power companies and their customers) would be a way to circumvent the inevitable efficiency loss of the Carnot (thermo-mechanical) cycle. Some of the schemes proposed include fuel cells, magneto-hydrodynamic generators, and even converting gamma rays from nuclear reactions to visible light for driving photovoltaic panels.

Register to Reply Good Answer (Score 3)
Active Contributor

Join Date: Jun 2009
Location: Atlanta
Posts: 15
#4
In reply to #2

Re: Is DC native voltage UPS the answer to total grid dependence?

06/16/2009 6:06 PM

Everything you say is spot on. But once more I have no intention to use home grown power to run appliance motors, (or make fire) other a than personal cooling fan like the one I am enjoying right now. We have two in the bedroom and one in each office that bring in the cool of the eve and cut down on Air Conditioning thermostat quite nicely..

My contention if we need to move away from Edison's lamps to LED. The next Gen of TV is power sipping LED that blows away LCD or plasma at a fraction of the power . Your Home theater in the box has 6 Class T or Class D amps. Great Multi room sound has been Cat 5 DC line powered like ZON audio. Cordless phones, modem you name it.

Looks like you made my point on the PC power. All that switching is heating up my office which then needs to be cooled by my HVAC system.

Laptops are battery powered, a smaller PC doesn't hurt my feelings, I'm done with towers like the monster that is cooking my leg right now.

The best and most important thing about a finite system as described is that it will educate the next gen to conserve. There is no answer without conservation save more nukes and lots more transmission lines, at least that we know of.

Besides when the power goes out I get real popular with my neighbors, they say they want one but are they willing to change behavior is the question.

All that is missing is the will, Leadership and standardization is the key.

__________________
Everthing changes or becomes extict
Register to Reply
Guru
New Zealand - Member - Kiwi Popular Science - Weaponology - New Member Engineering Fields - Power Engineering - New Member Engineering Fields - Electrical Engineering - New Member

Join Date: Sep 2006
Location: Auckland, New Zealand
Posts: 8778
Good Answers: 376
#3

Re: The Answer to Total Grid Dependence?

06/16/2009 4:55 PM

Sorry, could you briefly re-state your question? Are you just talking about the merits of off-grid generation compared to using the existing grid for powering say a home?

Have you looked at previous threads on the subject on CR4 where myself and others have discussed this?

__________________
jack of all trades
Register to Reply Score 1 for Off Topic
Active Contributor

Join Date: Jun 2009
Location: Atlanta
Posts: 15
#5
In reply to #3

Re: The Answer to Total Grid Dependence?

06/16/2009 6:11 PM

Please excuse my newbyness. There is so much out there that directly relates to this subject . Would you kindly point me in the right direction with a link? Thank you.

__________________
Everthing changes or becomes extict
Register to Reply
Guru
New Zealand - Member - Kiwi Popular Science - Weaponology - New Member Engineering Fields - Power Engineering - New Member Engineering Fields - Electrical Engineering - New Member

Join Date: Sep 2006
Location: Auckland, New Zealand
Posts: 8778
Good Answers: 376
#6
In reply to #5

Re: The Answer to Total Grid Dependence?

06/16/2009 7:21 PM

Your answering my question with another question, the thing is I cannot answer your question unless you answer mine.

Your discussions and statements are VERY broad and numerous (and quite vague), exactly what are you asking about (can you please be more specific)?

Are you actually talking about the merits of switching to DC instead of AC supply? Increased product energy efficiency? I would like to answer but I am still not sure what you are asking about. Do you have a specific question you would like an answer or link to? Jack - Confused Power Engineer

__________________
jack of all trades
Register to Reply
Active Contributor

Join Date: Jun 2009
Location: Atlanta
Posts: 15
#7
In reply to #6

Re: The Answer to Total Grid Dependence?

06/16/2009 9:23 PM

Jack ,

I have been hearing a lot about grid operators having to juggle base loads and scramble to meet peak demand. I own some property near lake Oconee which is a hydro facility that pumps water back up in non peak and lets water out to aid in surprise peaks! There have been many suggestions of how to shift loads to non peak hours to increase over all grid reliability. .

I've been around the consumer electronic business a very long time. having engineered and installed complete low voltage systems in hundreds of homes. I have some insights on just how wasteful my clients are and the entire industry is as it presently set up. Have been there let me assure you "Smart Homes" suck up more power!

I am a student of Edison having been raised in the shadow of his museum.

To Answer your questions:

  • No, replacing A/C in our current domiciles is clearly not feasible.
  • Yes, I am calling for help in the design of a new generation of digital devices

I will believe until proven wrong that each family can have "the power to choose" by taking personal responsibility to generate some power for the every day personal use in their ever expanding array of 21st century digital devices . The emphasis in on Safeguarding Security, communications and everyday ambient lighting while teaching their children to conserve a LIMITED resource. Lets have two systems DC simple Low Voltage Buss and a control/monitor on your wall to tell you about the two big C's, Cost and Carbon. We can develop dual fuel devices, Yep, they will cost more but that my friend has been what my industry has always been about.

I have many clients that budget $8000 -$12,000 for power back up they use a few hours a year at best. I know when they have been tripped because I get the service calls to go out and Cold Boot then re sync their A/V systems so their remote controls work right. That being said I've been installing more and more UPS to avoid these problems.

Bingo!The thought occurred to me why not just run the stuff on DC in the first place?

Who needs a Kilo Watt Surround Sound receiver anyway?

By installing a Low Voltage DC buss (V tbd) by need one can easily remove a significant part of our over all demand, especially at peak when the grid is least efficient. Even if the starter system needs to be recharged a bit at night.

This would encourage people to buy electric cars which would double as a storage device in case of extreme emergency, imagine how may Jules of energy would be available on that snowbound week! Remember we are not trying to make fire here just keep some lights on and contact with the outside world.

This coupled with a plethora of new devices of ever increasing efficiency are vital to maintaining our standard of living as we will always live in a disposable society.

Did you know a Motorola Cable DVR sucks up 1/2 kWh 24/7?

Sorry Jack the engineering field is all about numbers. I am talking vision and concept here. A concept that I am putting to work as we speak at very little expense so far.

Thanx for your time,

Rocky

__________________
Everthing changes or becomes extict
Register to Reply
Power-User

Join Date: Jan 2009
Posts: 187
Good Answers: 9
#9
In reply to #7

Re: The Answer to Total Grid Dependence?

06/17/2009 2:04 PM

"Did you know a Motorola Cable DVR sucks up 1/2 kWh 24/7?"

Over what period of time does it use 1/2 kWh of energy? If it is a year, or even a day, that would not be a significant amount to most people. But if it uses 1/2 kWh in an hour (i. e., 500 Watt power input), that is grossly wasteful for what it does.

I have always paid attention to the amount of power my circuit designs used. Usually, it doesn't take that much extra work to shave off a few microwatts here and a milliwatt there, and over time it adds up. This should be a point of special concern to those who design stand-by circuits. It is ridiculous to require 5 Watts or more for something that just sits there waiting for an ON signal from a remote control. We as consumers should demand to know the stand-by power needs of equipment before we buy, as well as the maximum power spec currently mandated by law. When the designers hear from Marketing that customers are concerned about this, they'll respond to stay competitive.

Register to Reply
Active Contributor

Join Date: Jun 2009
Location: Atlanta
Posts: 15
#11
In reply to #9

Re: The Answer to Total Grid Dependence?

06/17/2009 3:29 PM

I have not put a "Kill a Watt" meeter on it but it says 500 watts next to the plug and sure heats up a rack! There has got to be a better way .. The cable monopoly doesn't have to pay for the power so they give you no choice.

__________________
Everthing changes or becomes extict
Register to Reply
Power-User

Join Date: Jan 2009
Posts: 187
Good Answers: 9
#17
In reply to #11

Re: The Answer to Total Grid Dependence?

06/20/2009 10:51 PM

Wow! I think my 15 W DSL modem is a power hog, but compared to yours, it's just a piglet. You could threaten your cable company with a switch to a different ISP if they can't find you a more efficient box. (For example, the Linksys BEFCMU10 runs on 12 V 1A.) I would bet your cable company unloaded one of the first-generation modems on you.

Register to Reply
Guru
Popular Science - Weaponology - bwire Hobbies - Car Customizing - New Member

Join Date: Dec 2007
Location: Upper Mid-west USA
Posts: 7503
Good Answers: 96
#10

Re: The Answer to Total Grid Dependence?

06/17/2009 3:04 PM

You can lead a horse to water but you can't make it drink...........

__________________
If death came with a warning there would be a whole lot less of it.
Register to Reply Off Topic (Score 6)
Active Contributor

Join Date: Jun 2009
Location: Atlanta
Posts: 15
#13
In reply to #10

Re: The Answer to Total Grid Dependence?

06/17/2009 3:45 PM

Don't waist my time I'm trying to do something good here.

I think the answers are right in front of us .

I have built a simple system my electric bills are dropping.

Show me something besides a bad attitude .

__________________
Everthing changes or becomes extict
Register to Reply Off Topic (Score 5)
Guru
Popular Science - Weaponology - bwire Hobbies - Car Customizing - New Member

Join Date: Dec 2007
Location: Upper Mid-west USA
Posts: 7503
Good Answers: 96
#19
In reply to #13

Re: The Answer to Total Grid Dependence?

07/01/2009 3:13 PM

My numbers indicate the grid is only 8% efficent and the average house only 3% efficient.

Yes DC is actually inside the box in most appliances and A/V equipment and the power hogs can be cut by public opinion only.

__________________
If death came with a warning there would be a whole lot less of it.
Register to Reply
Active Contributor

Join Date: Jun 2009
Location: Atlanta
Posts: 15
#20
In reply to #19

Re: The Answer to Total Grid Dependence?

07/01/2009 3:41 PM

To date the "free market" like your cable monopoly has given us two choices , Use their 500watt power hog or no HD DVR at all.

We can change this... But how?

__________________
Everthing changes or becomes extict
Register to Reply
Guru
Popular Science - Weaponology - bwire Hobbies - Car Customizing - New Member

Join Date: Dec 2007
Location: Upper Mid-west USA
Posts: 7503
Good Answers: 96
#21
In reply to #20

Re: The Answer to Total Grid Dependence?

07/02/2009 1:42 AM

digital TV receiver not only receives Over-the-Air (ATSC)/Unencrypted ClearQAM (Digital Cable) signals but supports HD sound and image quality up to 1080i resolution, with variable aspect ratios of 4:3 and 16:9. Thanks to the high bandwidth of the PCIex1 interface you can watch flicker free HDTV on your Windows Media Center PC. Advanced PVR functionality lets you pause and rewind live TV, schedule recordings ahead of time and fast forward through the show to watch it at your own pace.

__________________
If death came with a warning there would be a whole lot less of it.
Register to Reply Score 1 for Good Answer
Associate

Join Date: Nov 2007
Location: Denmark, Aalborg
Posts: 53
Good Answers: 2
#14

Re: The Answer to Total Grid Dependence?

06/17/2009 5:05 PM

Hi Boogieman145, I like your ideas, and I have been wondering about the same things. I formerly worked as A/V technician, but I am also an electrician with 25 years of experience, and have always had electronics as a hobby.

To start thinking "green", one has to start with minimizing consumption. The biggest gain starts with low-tech engineering, such as insulation, and the fact, that a powerswitch can be set in the position "OFF".

Your ideas takes this a bit further, adding complexity and expensive technology. But hey, thats what I (we?) feel is fun, to challenge ones ability to overcome difficulties and save some money. When a kwh is put back in the grid by renewable, the price is a joke, but when you use your own energy, the price is the same. What is saved, is earned. And as the other thread started by elnav questioned, the powersaving technology has to be on the local level, and on the DC side of the grid. Otherwise the price runs wild.

On most routers and ethernet-switches the power in is 12 V DC, mostly 1 A or about, so some simple distribution with scrap automotive fuses and switches should do the trick. And when the battery is empty, a simple relay turns on the 12 V PSU, which of course should be the switchedmode type to gain some efficiency. Old PC PSU's could be made to do just that. In all, not much cost, just fun. And the save, well, I can save 200$/year on the electrical bill, if these devices ran on renewable, being wind or PV. So thats what my aim is. The difficulty is a steady 12 DC supply from a battery. When charged, the voltage is higher, and I'm not sure, my devices can take 14,5 V or higher. So I'm looking for a DIY DC-DC converter, 5-10 A, 8-20 V in, 12 V out. And efficiency around 95 % or more.

I have been experimenting with a solar heater, 2,2 m2 and 100 l watertank and with the ability to track the sun. My plan is to make an outdoor shower, so in the summer my wife and I can save on the hot water otherwise supplied from the coalfired plant, which, by the way, is the cleanest and most efficient plant in northern europe. But it takes a lot of time to make, and remake such a device to the point where it actually works...

But I'm enthusiastic about your ideas, so keep it up

Regards, moe

__________________
Don't think, play!
Register to Reply
Active Contributor

Join Date: Jun 2009
Location: Atlanta
Posts: 15
#15
In reply to #14

Re: The Answer to Total Grid Dependence?

06/17/2009 5:48 PM

Well Thanks Moe .. The whole object of my experiment it the change behavior we need to stop and think before we hit that incandescent light switch.

Here is an micro urban hydro idea.

My house has a 3/4 water feed with 100 LBS ! Wow of pressure before the regulator.

We use 11,000 gallons per month... I wonder how much power free power I could get while flushing the toilet?! LOL per month I mean.. Hell the heat in my attic can make electricity ..

__________________
Everthing changes or becomes extict
Register to Reply
Power-User

Join Date: May 2009
Location: Upstate NY USA
Posts: 148
Good Answers: 7
#16

Re: The Answer to Total Grid Dependence?

06/20/2009 8:19 PM

Rather than two grids- one AC and one DC- how about this:

Wire each house for 120v AC 60 hz and 12v DC. Use AC to power the big electricity users- air conditioning, water heating, refrigeration, etc.

Use one high-efficency AC-DC inverter for the whole house, to power the miscellaneous electronics. If you have your own power (solar, wind, whatever) feed that into the 12v system with a big UPS backup, so that the grid only suppliments and backs up your 12v home grid.

For me, it comes down to price. Until the total cost of home small-scale power per KWH comes down to less than the price per KWH at the electric meter, I'm not going there.

Sure, I care about the environment. We have an all-electric house, with a time of use meter, so you can be darn sure we restrict our power use as much as we can. Nuclear and hydro are part of the power mix we buy. And I pay taxes on 50 acres of woods, so our carbon footprint is seriously negative.

So why should I spend my scarce capital resources on a project that will increase my total cost per KW? That's financial suicide. Also, I am currently starting up a business (very green, BTW.) If myself and my partners had spent our capital resources on home solar panels and wind turbines, there would have been no money to start the business- and we intend our business to eliminate more fossil fuel and CO2 in the first couple years than the three of us will emit in a lifetime. That's an opportunity cost, which has to be figured in to the equation also.

Now, when we build our manuracturing plant, we will need a high pressure steam boiler as part of the plant equipment. So that is capital we already have to spend. And we need to supply heat, so that is also capital we have to spend. The extra cost to fuel the boiler with biomass will be more than offset by fuel cost savings, so that's a plus. And if we build our own turbine and get a surplus generator, the capital cost of the power part of the project will be less per KWH than the grid power. So we expect to have our factory pretty much off the grid, since we can do the CHP thing on the cheap.

As to the bullet points on the supposed evils of coal power, I will agree that anyone who agrees with you should not buy one single KW of coal-generated electricity, or any product produced with coal-generated electricity. Here in upstate NY we pay for power and delivery (transmission) separately, so we can choose whether to buy "green" power (at a higher cost) or the cheapest supply. Since my wife (who has the science degree) and I don't accept the science behind the "climate change" hysteria, we have no problem buying the cheapest power, and providing jobs for coal miners, railroaders and power pland workers.

__________________
ASCII silly question, get a stupid ANSI.
Register to Reply
Active Contributor

Join Date: Jun 2009
Location: Atlanta
Posts: 15
#18
In reply to #16

Re: The Answer to Total Grid Dependence?

06/30/2009 11:08 AM

Selling power back through a grid tied system is a fixed game. Let me explain why my friends.

As I see it there are plenty of ways to harvest energy to supplement grid dependence .

I also grow a small vegetable garden. I use and enjoy what I grow without first having to sell it back to the supermarket packaged the way they want it then by it back!

Using 21st century technology to push power back into 19th Century legacy infrastructure is futile.

I am harvesting a small amount of solar energy, storing it in a deep cycle battery and using it to run this PC. modem, some of my house sound system, my security system and ambient lighting 24/7. I will see how a change in my family's behavior effects my power bill. Right now, at the summer solstice, I'm harvesting as much as I can use free for these devices. In the winter or with a string of multiple cloudy days I have a back up charger that kicks on at night. I have not plugged it in yet tough.

__________________
Everthing changes or becomes extict
Register to Reply
Register to Reply 21 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Boogieman145 (10); bwire (3); jack of all trades (2); Mark Stockman (1); MNIce (3); moe (1); tcmtech (1)

Previous in Forum: Where'd the Wind Go?   Next in Forum: Sustainability Debate – 1

Advertisement