Newbie here-What do I need to run a server by solar power?

[fta123]

1. So make a PC power supply that has 3 external connections.
Q- Did you mean modify the PSU in the computer? and how?

2. Then sell it with a 50w or 100w solar panel
Q- Sell it? I didnt understand that--

Because of that, during the bright part of the day, the panel will be providing most, or just barely all, of the power for the PC. The wall plug will provide the rest. At night, the wall plug would provide all the power. It's a grid-tie but it doesn't feed power back to the grid, it just reduces demand on it. The 100w panel takes 100w off the grid load during the peak demand times

What can I do if I just want to have a system that run on its own, from either batteries....meaning....a way to run during the day from direct sun light and at night from batteries...I hope im not confusing you

[Theila]

fta123 - I think it's cells.

This is interesting David.

The cells would provide straight DC though. Wouldn't you need a regulator? As for using batteries instead of the grid, just use a bank of batteries that have the same rating as the cells?

[mgopilot]

Just for the computer, flat screen, printer scanner, and other peripherals--figure 400 watts for 24 hoursor 9,600 watt hours per day. Take your average winter sun in hours and divide the 9,600 by that. That will be your array size at full tracking efficiency, for fixed Unisolar type panels add 20%. For fixed seasonally adjustable glass panels add 60%, for single axis tracking add 20% for glass, and 0 for Unisolar.
Now you will need storage capacity for the maximum days you could have without sun. This is in amp hours at the system voltage. Add 10% for all losses. You will need the DC inverted to AC of double for starting. So an 800 watt preferably sinewave inverter minimum. So you'll be using a total of 91 amp hours per day. Say you go with 350 amp hour L-16 batteries in pairs for a 12VDC system, each pair give you 70 Ah @ 20% max discharge for max life. Say a week without sun is possible--7x91=637 divided by 70 and rounded up to the nearest whole even number= 10 sets of L-16 batteries. A Prosine 1000 inverter will do the job nicely.
Let's say you average 4 hours sun in winter=2400 watts in panels. Add 20% for the cheapest and easiest fixed unbreakable Unisolar 64 watt panels. That is 45 US64 panels (180 amps at 12VDC!!!). It would be best to have a grid intertie system with half the batteries and panels. System expense would be roughly 60% and you would break even on power expense. This is all very rough. For an exact system go to a tech rep at http://www.realgoods.com You are probably looking at a minimum of 14k USD, minimum, do-it-yourself. Do not forget to shield from the inverter VHF/EMI.

[fta123]

That was very informative and Im glad you break it down. I been doing some research and looks like a mini-ITX motherboard ( www.mini-itx.com )with a 60Wpower supply should be sufficient to run the system. The system would be a stand alone web server; no monitors or printers will be running. What type of panel would you recomend?, below is a link to a web page that explain a little about power supplies for that type of motherboard, maybe you can take a look at it, thanks mgopilot

http://www.epiacenter.com/modules.ph...er+Supplies#43

[mgopilot]

You will need 6-US64 panels on fixed south, latitude angle, mounts with wiring of 10 guage to keep them at 12VDC nominal to a 30amp charge control (w/desulfator), ground rod, and 4- 6VDC 350 Ah or better L-16 batteries hooked up series/parallel for 12VDC with heavy cables, to a heavy duty 12VDC voltage regulator, then to your unit. You could substitute the 4-L16s for 6- 220Ah golf cart batteries. This is using a 5 hour minimum winter sun and 3 days cloudy maximum, with allowance for line losses, and best battery life. Adjust battery bank size for cloudy days max, and array size by winter sun min with no less than one US64 or equiv per golf cart size batt. You are looking at about $3,100, do-it-yourself for the first system, and more with bigger array and bank size. Depends on where it is. In a windy location, an AirX is a consideration instead, or with panels. Search the web for the best deals, except get the batteries, wire, cables, L-metal, bolts and nuts, and ground rod locally. Read a book on installing/sizing/maintaining solar from the library. It is easy, really.

[Richard]

I would have thought that the companies that supply the components would be able to do you a site-specific assessment and design.

[mgopilot]

Originally Posted by TheRobster

I would have thought that the companies that supply the components would be able to do you a site-specific assessment and design.

I gave him the general system under the stated conditions, AND gave him the link to get a tech rep from a supplier. Anyone who wants to go with alternative power systems should do their own site specific analysis using the forms at various solar/wind web sites. Realgoods is the first and best as far as help and a wide variety of goods. They have the Solar Living Sourcebook in possibly its last year of publication, and it contains the site survey and system surveys charts and forms. However, they don't have all the lowest prices. If someone can't do their own survey, they are too dumb to even have a system.