Solar system for workstation computer.

2 Posts
Mar 23, 2009 06:30 pm
Solar system for workstation computer.

Hello, I’m interested in solar systems but I never did something.
Now I like to know if some one can helps me to setup one off grid system.
I like to maintain one pc desktop running with one solar system, I know I need solar panels and battery’s but I have no idea what’s the best setup
I know I need the solar panes.  ( ?)
Battery’s (?)
Converter form VDC to VCA
I live in Ventura County, near to LA

I don’t know what else I need but I like to have this system running all day, if the cell panels doesn’t have enough power (night) I like to have the battery’s start working and when I have enough sun light (day) I like the Pc start getting the power from the solar cells or still on the battery’s but the solar cell can start re charging the battery’s

I’m not sure if that’s possible or not, in advance thanks for all your help.
Mar 27, 2009 06:21 am
Re: Solar system for workstation computer.

If your not in any big hurry to have a PV (Photovoltaic) system, you could learn a lot from its full of articles from people who have built there own PV systems or have had their PV system built for them. Both large whole house off grid PV systems and small dedicated load PV systems.
Take a look. There are advertisements for PV system sales, service and, installation contractors.
Here is a place, Its in Victorville, CA. about a 2.5 hour ride from Oxnard CA. If you get out that way it might worth the time to check it out. They have some pretty good prices on PV and related system devices.
You will want to know just how much power your computer requires for the amount of time it is to be on in kWh's (kilo-watt-hours). There are simple kilowatt recorders that plug into a wall socket and you could plug in your computer system to the kilowatt recorder. Here is an example of one but you might be able to get it locally and cheaper at a home improvement/building supply store. Here is another place you could try to find a PV dealer/installer closer to you.
2 Posts
Mar 27, 2009 11:53 am
Re: Solar system for workstation computer.

Thank you very much for all this important information, this is a good start for me, I like to do all by my self and this information is very helpful
I will follow all your recommendations.
And again thank you for all this information.
Mar 27, 2009 01:42 pm
Re: Solar system for workstation computer.

No problem Francisco.
Typically, my computer and monitor will draw around 11 amps at 12 volts dc nominal, from my 600 watt Samlex pure sine wave inverter. This is at night when, of course, there is no sunshine so its all from the batteries.
11 amps X 12 volts = 132 watts
So for each hour that it is on, being used, thats .132 kWh's. If I am on the computer for 8 hours that would be,
8 hours X .132 kW's = 1. kWh (By the way, a power company might only charge about $0.12 for that.)

Now to figure out what it would take to create an off grid dedicated PV system just for that (and maybe a small desk lamp), I would look at the 11 amps and multiply that by 8 which is 88 amp hours. To size a battery bank I would at least multiply that 88 amp hours by a factor of 5 so that, what is used from the batteries is only the top 20 percent of battery capacity. Doing this helps the batteries to live an over all longer life and it is easier for the PV array to recharge them the next sunny day.
5 X 88 = 440 amphour battery bank at the 20 hour rate.
Remember, this example is at 12 vdc nominal.

Your location would have about 5 to 6 hours of equivalent full rated power from a single PV module.
This is based on an average over one year with the PV module mounted at an angle equal to the latitude, facing solar south. What this means is, if it where a single 100 watt PV module, in a whole days time it might make as much as .5 kWh's. There are a lot of factors to take into account for your exact site like; trees, buildings, smog, and of course, the weather.
Now to figure out what I would need for a PV array.
I would take that 1. kWh and divide that by 5 hours of equivalent full rated charge, 1000 / 5 = 200
So at the very least I would need a 200 watt PV array. I would probably increase that though. Maybe even double it to a 400 watt PV array. Doing that could make a big difference in keeping the battery bank in the top 20 percent of full charge on those cloudy days and such.

From this example I would know that if I wanted a dedicated PV system for my computer I would need at least a; 400 watt PV array, 440 amphour battery bank, 200 watt pure sine wave inverter and of course, PV array mounting, charge controller, wire, conduit, breakers, fuses, disconnects, etc., etc..
There is quite a bit of stuff to safely conduct all this power and you will need to know the correct size and type wire, breakers and, such for each particular use such as PV array to charge controller or batteries to inverter.
Me personally, I keep a fire extinguisher near my stuff. You just never know when or why but something can happen. I have learned that, when dealing with electricity its not so much a matter of probabilities as it is possibilities. It may not happen but it can happen and thats enough for me. One can reduce the probabilities of an electrical fire greatly if one follows the NEC. (National Electrical Code)

My only advice to you Francisco is, if you plan on designing and installing your PV system yourself, take your time now and learn all you can about safely conducting electricity. If you are not, or don't have a friend, that is an electrician familiar with the NEC, make one or learn the Code.

Some more places to learn are;
(Look accross the top of the page at the above site and go to "publications" then scroll down to "codes" and go to "John Wiles code corner." These articles were written and published in Home Power magazine.)
and then there is,
« Last Edit: Mar 27, 2009 01:47 pm by Thomas Allen Schmidt »
33 Posts
Mar 27, 2009 07:53 pm
Re: Solar system for workstation computer.

You can do this two ways. Keep everything AC and just put a big enough battery into the system to run it all night and a big enough array to charge it all up every day. But it's not very efficient.
I have my computer converted to DC. You can find DC-DC power supplys here.;jsessionid=0a0108421f43fbe472a2775d4fcd99c08cc470fe4c04.e3eTaxePaNqNe34Pa38Ta38Oa3b0

My cable modem is 12v DC so it was just matter of running it off battery instead of AC brick. I'm still working on the monitor portion of it. Alot of pressure from consumers needs to be put onto electronic giants to make them stop putting AC power supplies in monitors and allow for external brick supplies. I found one 15 inch TV 720p low rez monitor so far that is like this at a trucker supply online store. It's rediculous. PLus the only thing that fails in LCD monitors is the power supply and they are expensive  and many of them don't even have fuses and it's all a rediculous waste.

Easiest is just keep the computer all AC but you pay dearly in array sizing and battery sizing that way. Where I'm at we get about 100 days of fairly disruptive cloudiness a year and some seasons are pretty bad for cloud cover.

I'm not totally there and converted but I have most answers you would probably need to do this.

Disclaimer and Disclosure

The Alternative Energy Store, Inc reserves the right, within its sole discretion, to refuse or delete any posting or portion thereof, or terminate or block the access to this forum.

The opinions and statements posted on this forum are the opinions and statements of the person posting same, and do not constitute the opinion or act of the Alternative Energy Store, Inc (AltE). The Alternative Energy Store, Inc does not endorse or subscribe to any particular posting. No posting shall be construed as the act or opinion of the Alternative Energy Store, Inc.

Click here for BBB Business Review

McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams
Desktop Website | Mobile Website


Click on an icon to share! If you don't see the method you want, hover over the orange "+".


What can we do to help you?

Please enter a summary
Sorry, the copyright must be in the template.
Please notify this forum's administrator that this site is using an ILLEGAL copy of SMF!
Copyright removed!!