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DYI Solar-Powered PC Solar Components

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September 25, 2007 11:43:12 AM

http://www.tomshardware.com/us/2007/09/25/technical_foundations_diy_solar_powered_pc/index.html

In Part 3 we focus on the hardware for the solar arrays used to generate power for our PC. We fretted over every half-watt to obtain the longest possible up time even on cloudy or rainy days.
September 25, 2007 2:43:27 PM

What is DYI?

Do You Itself?
September 25, 2007 3:34:46 PM

What a wonderful article! I learned so many things like that the sun rises in the east and sets in the west. Or that thicker cables have less resistence than thinner ones. Amazingly, the authors also tell us that green/yellow cables are more "efficient" than blue cables. These examples about sum up the fine quality of the writing even though, some subtleties might have been lost in translation.

I also fail to understand the point of the undertaking. It would have been a lot easier, cheaper, faster and logical to just use some notebook - may be with a red keyboard for efficiency...


Related resources
September 25, 2007 4:05:06 PM

Not to mention, who cares about the power savings when you're paying 4 grand for a low end PC?

Pointless.
September 25, 2007 4:30:41 PM

Agreed! The whole thing is dimwitted and quarterbaked. Let's see:

With an assumed average consumption of 90W for the computer and the display, the solar maximum output is just about 4 times the load. Considering that it you never get the maximum output in wintertime and that there will be only about 8 hours of usable daylight (if at all), the system couldn't stand a single day in January. No way.
Running on battery alone, the system wouldn't survive much more than a day. What's the point of a battery at all - especially considering that a battery has a limited lifetime (5 years or ~$100/year or about $0.27/day or about the same as the potential cost of buying the energy from the power utility).

It is a great idea to use powerefficient equipment including computers and using clean, green energy is fine, too. But using solar energy in high latitudes for 24/7 computer operation makes as much sense as using hydro-electric energy in the Sahara for a space heater.
September 25, 2007 6:57:00 PM

Ditto. Nevermind lack of research into DIY solar in general. A couple of issues of Home Power magazine would have done wonders for their setup. Turntable tracking is a joke. If you're going to add complexity and failure points of solar tracking at least do two axis perpendicular. How many days until that OSB, rope, and hand drill setup dies? And how many days did it take to build a system that is inefficient and prone to failure? Drop tracking altogether and just add another cell. And drop the battery and direct 12v power supply. Run grid-tied with a laptop if you want an efficient solar PC.
September 25, 2007 7:20:28 PM

Don't forget to add something that will shovel the snow off the cells in the winter.

In some places you can sell your power back to the power company... that would be cheeper then the battaries.
Most nights the system would be running idle. So it wouldn't consume as much power.

how many solar panels would you need to run a high end overclocked gamming system.
Most people reading this would have high end systems.

my 2¢
a b B Homebuilt system
September 25, 2007 11:46:14 PM

Lets not be too mean here...

There is translation so the green/yellow cables are more "efficient" than blue cables does have a picture clearly showing the larger wire is whats efficient.....

My question is....Looking at the live stats the pc seems to go down allot. Is it running out of power at night and shutting down?

Worst case you still have a super efficient(not for games...but still ok for most other things....) PC to use with the power utility....
September 26, 2007 12:22:56 AM

Well, the green/yellow cables were just an example for the overall "journalistic" quality of the article. I could have chosen amongst at least 20 other examples.

Of course, the system goes out a lot. The battery and the solar panels are too small to support 24/7 even in September. Or may be the wooden panel frames are just shaking in the wind. In other words, your own observations are proof that the autors did not (!) succeed "in building a desktop PC system that runs completely and exclusively off solar power".

In the worst - and obviously existing case - the article totally missed - amongst others - its title ("DYI Solar-Powered PC Solar Components") - even though, come to think about it, I have no idea what the title really means.
And I would challenge the claims about super efficiency. They are not substantiated; any similarly powerful notebook (like C2D with a mobile graphics card) would be running with less than 40W of average power consumption and it would be at least equally powerful and probably a lot cheaper. The rediculous explicit claim of "world record" may justify a little sarcasm. It also just distracts from the importance of power efficiency and usage of renewable energies.
a b B Homebuilt system
September 26, 2007 1:53:49 AM

I wonder if wind would have done better?
September 26, 2007 7:51:34 AM

nukemaster said:
I wonder if wind would have done better?


You would need to live in a windy area to begin with and a giant wind generator will probably be more of an eyesore than the rigging for solar panels.

The article is a decent concept with not much practicality. Even the author stated that.

Something more practical would be to set up a solar cell array to supplement power to a house. Thereby reducing dependency on your local electricity provider. But that's beyond THG's scope.
September 26, 2007 7:19:01 PM

Project lifespan??

I am sorry to say, but I do not think Your experiment will last very long :heink: 

First thing:

Your power budget is 534 KWh annualy if the computer is supposed to run 24/7.

1 KWp (One Kilowatt of rated solar panel power) will in Denmark yield 800 KWh per Year. You live further south, so I will credit You another 200 KWh. If You have the same Solar input all Year round, (which is impossible unless You live in Africa near the equator), You will still need at least 600 Watts of Solar Panels.

Next thing, Your Storage Battery.

I am really looking forward to see to how long You take to run the battery completely down.

Lead Acid batteries made for Solar Power or Marine use, can withstand a discharge down to 50% of full charge without damaging the battery. Some batteries even alows You to go to 30% SOC on occations, but not always.
If You discharge below 50% SOC (state of charge) You will shorten the lifespan of the battery. Discharge it completely and You will cut the lifespan in half in one go.

So, If You want Your $500+ battery to live much longer, You need one more battery equal to the one already obtained. Next, remember to set the charge controller to Solid GEL, if this option can be selected. Solid GEL Batteries cannot be overcharged like ordinary lead acid batteries.
I trust You obtain the consumption through the charge controller. This way You may save Your battery's life because a decent solar controller cuts off consumption before the battey discharges too much. Regrettably I am not able to find Your charge controller's data.

Please don't be offended. I am sure You tried to think of everything, but You are obviously new to solar power.

Best of luck.

ChrisD


September 26, 2007 8:49:07 PM

I think some people r missing the point. a computer that runs 24/7 completely off the grid. where you only option might be a gas generator. in remote locations has huge merit. although i think a laptop with solar might be a better choice. i am thinking 3rd world.
September 27, 2007 1:50:01 PM

ccc10156 said:
-snip-
Lead Acid batteries made for Solar Power or Marine use, can withstand a discharge down to 50% of full charge without damaging the battery. Some batteries even alows You to go to 30% SOC on occations, but not always.
If You discharge below 50% SOC (state of charge) You will shorten the lifespan of the battery. Discharge it completely and You will cut the lifespan in half in one go.
-snip-
ChrisD


The battery has been hovering around the 12V mark for the past few *days*; it looks like as soon as there is enough energy to run the computer, it's turned on without regard to the battery's state of charge (whereas every effort should be made to prevent the battery from going below 50% SOC). The $500 battery will die from sulfation if it never gets recharged--as it looks like is quite possible with the usage pattern.
a b B Homebuilt system
September 27, 2007 2:44:14 PM

Above mentioned practical flaws aside, as a concept article (however poorly executed), I think it served its purpose. We can all think of practical improvements, from adding another panel or two while forgoing tracking, to increasing battery capacity; but if you needed to run a computer in a remote location where power was an issue, yes you would use a laptop. While parts of the article (perhaps as translated) are downright silly, it is still thought provoking, and I enjoyed reading it.
September 27, 2007 6:21:20 PM

I agree with you, jtt283, the article, project, and concept are downright silly. Nothing, but really nothing makes any sense. However, I enjoyed reading it. I laughted a lot.
Yet, I am not quite sure if THG was the right place for publication. May be "Mad" would have been better.

More seriously: Are there any conceivable reasons for running a desktop (not server) 24/7 without putting it to sleep mode when unused?
September 30, 2007 12:44:45 AM

Like pretty much everyone else is saying, good idea, bad implementation.

I would have definitely used a laptop, but, if I was going to do a desktop system, I would have definitely used an underclocked processor, and 2.5" hard drive. Since you wouldn't reasonably be using this system for anything too extreme, an underclock and undervolt would be reasonable, and lower power consumption a LOT.

2.5" hard drives aren't exactly hard to come by either, and it's not like they'd be storing a ton of data, so I think one of those should have been used as well. The argument that they wanted to use off the shelf parts doesn't work, because the PSU wasn't either.

As for the battery issues, you guys are all pretty much right in saying that that battery isn't gonna last long at all, a little more research in that department would have went a long way.

I think the concept of a computer running of nothing but sunlight is pretty cool, but it's completely unreasonable to ever use in any circumstance (at least until solar cells get WAY more efficent and way cheaper.)

Sapit, I leave my computer on 24/7 simply for convenience, and in case anyone wants to leave me messages via MSN. It's hardly costing me any money and it's near silent, so why not? I do underclock it overnight and when I'm gonna be gone all day, at 400mhz and 0.9v the cpu pulls about 4w full load, the hard drives shut off after a certain amount of time, monitor shuts off, etc, so it's really not pulling much power. This may also sound strange, but I can't sleep without the ever so faint hum of my computer running, without it on it's just too quiet and I can't sleep. Doesn't make much sense but yeah...
a b B Homebuilt system
September 30, 2007 3:00:21 AM

400.....what cpu is it....i cant get down that low....

think 1200 is the lowest i can go....never tried....but 800(QDR) fsb is as low as the board goes to my knowledge....

so 6 x 200 = 1200
October 1, 2007 7:22:11 PM

from the looks of the system thay need 2 more solar panles and maybe 2 batts and that should be able to keep the system going for longer

good try tho

my server gives me my hum to make me sleep (2 to 6 of the disks spinning away :)  )

-------------------------------------
UK THG web site sucks as thay are not linking to forums i only found this by some how been able to use the USA web site

None of the UK main page stuff links to forums thay have an comment system that no one uses

All main page stuff should go into its own thread ( like bit tech does http://www.bit-tech.net/ that web site works very well)
October 2, 2007 1:09:26 PM

You guys don't get it. You should be laughing at yourselves. As clearly stated throughout the whole series, this was a test, a concept, a what if scenario approached from the POV of the average Joe faced with what is available out there. How would we ever know if this is or isn't a viable solution if no one has the balls to see for sure.

I can see the the limitations now and the complexity and difficulty in getting it all put together. I can now see that its more expensive than I would like it to be and that it would require more money to make it stable and longer lasting.

But I would never have been able to reach those conclusions without these two guys going out on a limb and building it for us. So ya'll can just STFU, unless you have something better to show us.
October 5, 2007 9:24:11 PM

I liked your article because it was interesting. I have been looking at solar power for a while and if I had some extra money I might dabble a bit in it. I have looked at a lot of articles on www.homepower.com. They charge a subscription fee nowadays so you cant just download the magazine anymore. However they use to have lots of interesting articles.

I saw a show on the TV where people in Germany can sell back Electricity to the power company and that some people were doing this for profit. So if I were in Germany, Keeping that in mind, I would suggest building the Solar Panel Array in overkill. I would have suggested using two batteries and at least 4 Solar Panels. Some people may not realize that Germany has a Pro-Active Solar Power Initiative.

Did you plan on using DC or AC to run the computer? I know there are some MINI-ITX parts and some Intel parts that might run off of a low-power, DC Power Supply. However, if you could plug a laptop into DC that might be more efficient in some cases. The Mini-ITX websites may have some useful information on this.

If you were using AC power you would need a Sinewave Power Converter. They range quite a bit in price and Quality. You may also want or need an optional AC powered charger for the batteries for exteded Snowy or cloudy days. I have seen in several places that the power loss is less if you are running a power converter from 24 W DC -48W DC to your standard 110w or 220w (european). It is a debate as to which is more useful.

I dont think that you mentioned that some batteries give off a gas that is flamable. Normally batteries are placed in a ventilated battery box. Also when working with batteries with that many watts, I would suggest having a Fire Extinguisher handy. Also another reason for the battery box is a Lead Acid Battery might Leak acid on some rare occassions. Also there are some additives you can put in the battery that make them last longer. Those batteries can get quite pricey.

Another option for this solar installation could have been a portable Solar Power Kit that already has the solar array and battery and charger and volt meter ready to go. Still the article was very interesting, because it showed that there is a need to Over-Engineer your power requirements if plan on having plenty of storage and charging capacity.

Be very careful around those deep cell batteries. You can see where hooking up multiple batteries could increase the danger significantly.

Keep up the good work.
November 29, 2007 1:11:40 AM

Hi
Why using 12V and not 230V?
And why don't using 2x200w (or more) solar panel ?

I want to build solar system for pc usage and i calculated and i need 600w but i want to use only 1 or 2 solar panel (180-200w).
if anybody have some great idea pls post.

sorry for my english (i'm hungaryan)

great job but the capacity is lower
a b B Homebuilt system
November 29, 2007 1:30:16 AM

They used 12 volts because there is a loss(heat) of power when you step up 12 to 230 and then another loss(the heat your psu makes is a loss of power) when they step the 230 back down to 12. They save them self anywhere from 30 to a whooping 50% power by keeping the system 12 all throughout.

What PC do you have that needs 600 watts?

My system takes 330 watts from the wall(would be a good 20% less if i did the 12 volt trick they did...more so if i went solar panel step up to 120[the voltage here] and back down to 12. that would put me in the 30-40 percent range)

Here is the system i speak of:

Case: Antec 900
PSU: OCZ 700watt
Board: P35 DS3R
CPU: Q6600 @ 3.00
CPU cooling : Zalman 9500 @ 500-2200 rpms(PWM)
Memory: 2x 1024MB ,2X 512MB @ 4,4,4,10
Video: 8800GTX 600(core) 1400(shader) 900 x2(memory)
Storage:
2x WDC 250gig (Raid0)
2x Seagate 320gig(Storage)
2x Seagate 500gig(Storage)
1x 500gig Seagate (Backup-external) - Not in the power count
Optical drive: Samsung SH-W162
KB/Mouse: Logitech Elite wireless(MX 700 out of service), G9 Mouse
TV card: PVR 250
Sound: Creative SB Audigy 2zs
Screen: Samsung 950b (LCD)(not included but it takes 30 watts)
Speakers: Altec Lansing Select 641(12-30watts for average listening)

You may get away with less power then you think....the trick is to store enough power in the batteries for night time...and have at least an extra panel to charge and run things on cloudy days....
November 29, 2007 1:34:42 AM

Now-a-days, The only responses to articles at Tom's are negative. If you don't like the article, move on.
a b B Homebuilt system
November 29, 2007 3:11:29 AM

aadamszc said:
Now-a-days, The only responses to articles at Tom's are negative. If you don't like the article, move on.

Whats that about. there was just a question about the article.....i answered it...nothing negative here....
November 29, 2007 12:13:22 PM

nukemaster said:
They used 12 volts because there is a loss(heat) of power when you step up 12 to 230 and then another loss(the heat your psu makes is a loss of power) when they step the 230 back down to 12. They save them self anywhere from 30 to a whooping 50% power by keeping the system 12 all throughout.

What PC do you have that needs 600 watts?

My system takes 330 watts from the wall(would be a good 20% less if i did the 12 volt trick they did...more so if i went solar panel step up to 120[the voltage here] and back down to 12. that would put me in the 30-40 percent range)

Here is the system i speak of:

Case: Antec 900
PSU: OCZ 700watt
Board: P35 DS3R
CPU: Q6600 @ 3.00
CPU cooling : Zalman 9500 @ 500-2200 rpms(PWM)
Memory: 2x 1024MB ,2X 512MB @ 4,4,4,10
Video: 8800GTX 600(core) 1400(shader) 900 x2(memory)
Storage:
2x WDC 250gig (Raid0)
2x Seagate 320gig(Storage)
2x Seagate 500gig(Storage)
1x 500gig Seagate (Backup-external) - Not in the power count
Optical drive: Samsung SH-W162
KB/Mouse: Logitech Elite wireless(MX 700 out of service), G9 Mouse
TV card: PVR 250
Sound: Creative SB Audigy 2zs
Screen: Samsung 950b (LCD)(not included but it takes 30 watts)
Speakers: Altec Lansing Select 641(12-30watts for average listening)

You may get away with less power then you think....the trick is to store enough power in the batteries for night time...and have at least an extra panel to charge and run things on cloudy days....





hi
i'm not calculating my watt only i thinked this is the maximum :) 
You have a great configuration:) 
My configuration is same like your.

PSU: Mercury 550 watt
Board: m2n31-sli deluxe
Cpu: amd x2 4600+ (2.4 ghz)
Cpu cooling: what was in the box but i want to change to zalman (to hot the cpu)
Memory: 2x512(kingston CL5) 2x1gb (kingston cl5)
video: Ati sapphire x1650xt 256 600/1400 mhz
Storage: 2x 200gb maxtor
optical drive: nec dvd-rw nd-3540A
kb/mouse Logitech MX revolution
TV card: Leadtek winfast 2000xp global
sound:1 i mainboard and 1 c-media 5.1(for tv card)
screen: - fujitsu siemens LCD 19" L-191
- 15" crt (for tv card)
speakers: Genius SW-HF 5.1 5000

Exist some kind of software what calculating my pc watt usage or i need to add all component one by one?
thanks for the help
November 29, 2007 12:28:24 PM

i want to build solar system but i don't now what voltage use 240 or 12.
240 would be perfect but you sayd to much the power loss.
i thinking how i can resolve to workin my pc in 12 volt (i need to look up for 12v monitor )
a b B Homebuilt system
November 29, 2007 3:32:35 PM

The best way to get your current PC power use is with something like a Kill A Watt meter, they sell then at most hardware stores.

now for the Why 12 in more detail

When toms did there solar PC. They wanted to use as little power as they could. That is why they went with 12 volts. you can use 240 is you want. There are some advantages that i will talk about later.

Have you ever noticed that power bricks get warm or even hot to the touch. This is because the transformer(the part that is turning your household power from 240 volts to lets say 5 for lets say your phone)looses some power in the form of heat. This also happens when your solar system converts(steps up) the 12 volts to 240. So if you loose 15% stepping the power up to 240 and then your PC's power supply looses another 25 percent to step that 240 back down to 12 you have to generate(with more solar panels) 40% more power to run the same PC

Now running 12 volts has some limmits. For one this it will only run your PC and maybe an LCD(if like toms you have one that runs on 12 volts) screen. To run the CRT or anything other equipment(desklamp ect) you will need to step the power up to 240.

Another thing you have to do with 12 volts is run VERY large cables(think car jumper cables or even bigger). This is because at 12 volts you need many times more amps to get the needed wattage

700 watts at 12 volts is 58.3333333333333333(well you know lots of 3's), So lets say 59 amps
700 watts at 240 volts is only 2.9166666666666.....7. So lets call that 3 amps

so while 700 watts at 240 volts needs a AWG 14 or 16 wire at 12 volts that same power needs a AWG 6(smaller numbers mean bigger wire)

The best of both would be to run 12 volts to the PC and run 240 to a plug for one or 2 other devices(this will limit the loss to only what you plug in...and not your PC, but the more you run the more power you need)

Disclaimer: Check local code for AWG ratings. how do i know what its is over there :) 

Now on the the 12 volt PC

A pc does not run on 12 volts alone. It also uses 5 and 3.3. So what ever psu you get it has to take 12 and convert it to the need 5 and 3.3 also used by modern PC's. There may even be some -5 or -12.

a quick Google shows up this

http://www.powerstream.com/DC-PC-12V.htm

I am sure there are many more out there.

Just know that you have a rather big job ahead of you to begin with. you will need your panels and battery system to store for overnight use.

While you are looking at alternative you may also want to look into wind. The advantage there is that even at night you should be able to generate power. This only works well if you can get it into an area with enough wind(think fairly high)

Some kind of a site serve may be needed to check the wind at different altitudes and times.

If you do chose to undertake this massive project. post your results so others can learn from what you have done....

good luck
November 29, 2007 9:30:17 PM

thanks a lot your help
November 29, 2007 9:46:13 PM

Muk ---

I noticed that there was a bit of initial math for computing the amount power and solar area and all ...

It should have been easy to design a system that would function in a more usable manner. (After all we know that solar power works well enough to power remove equipment full time.)

I agree with others that a lot of poor choices were made. Enough that the entire project looks like a high school kid did the work.

May 20, 2010 1:51:49 AM

I agree that all of the solar power components are working properly in the area whereas it is good to absorb solar power energy.
July 12, 2010 5:01:23 PM

I like the concept but why not just build a 12 volt panel (about 36 monocrystalline cells) and you can plug five such computers into it all day and even take it outside.
!