VERY Remote OT:Power for very remote sites

fftop:Hi group...I was just charged with spec'ing / maybe suppling 5 power systems for a very remote location...lots of sun, not too extreme a temperature swing.
I'll need enough storage to carry thru about 3-4 cloudy days, with a peak load capacity of 5500 watts@120 vac, or 3000 watts at 240 VAC and / or 50 amps @ 24VDC. Wind is not an option, so it will need to be Solar. Stationary panel, or Tracking Panels???Most of the sites have good exposure to the sun for most of the day. Anyone have expertise in this area that would like to do some consulting? How about equipment mfg'rs/ suppliers? Oh one last requirement...delivery will be by Backpack/ Mule / Donkey/ maybe a Gator if we are lucky.

Thanking all of you fine folks in advance.....:site:

David

Dave

Are these loads 3 phase or single and do they also include DC loads at 24VDC?

were those power values describing a 5,000 watt load or were they energy ie 5,000 kw hr. If they are a 5 kw load how long does the load run per day to yield kw hr. This would be needed to determine battery capacity in terms of Amp hour. It would also be need to size inverter.

Curious about doing this cartage with a Gator.

Here in Seattle we have troubles with this animal rights group ie PETA. You may run into problems with them.
Also will you have to muzzle the gator to prevent biting?

Dan Bentler
How much can a gator carry anyway?

Sun power corp. installed a 1 M/W system where I work. It's a pretty impressive system. I'm not sure if they have a packing outfit though. I'm more interested in the remote spot?

Sounds like a government job.

It's NOT a Gov job...

Gator=John Deere 6 wheel ATV

I'll have to pin down more of the power requirements when I talk w/ them tommorow...:site:

Dave figured that it was one of those ATV rigs - just had to try for a grin

Am interested in project and when or if things need to be TOP SECRET go ahead and PM me.

Dan Bentler

You might look at the site: www.otherpower.com/
The chat section is at www.fieldlines.com/
Lots of good help there.

David,

We work with Sunelco quite a bit. They can take your requirements and come up with a system that will handle your requirements.

Joe

Here's another link:
http://www.kyocerasolar.com/

Some of the remote microwave stations here in BC have thermal generators powered by propane. I don't have any details but I imagine it doesn't require large batteries.
Another idea would be a fuel cell. These can run on a wide variety of fuels e.g. a Methanol / Water mix is used here by a company that replaces the battery pack in electric forklifts. Hydrogen of course is used for cars & buses
Roy

Hey thanks everyone...Great links...I will keep this one alive while I sort out what we need for this project...who knows, I may even incorperate a system here on the Solace farm....

David

leitmotif said:

Dave figured that it was one of those ATV rigs - just had to try for a grin

Am interested in project and when or if things need to be TOP SECRET go ahead and PM me.

Dan Bentler

Click to expand...

Dave
When sizing your system assuming
you are using storage batteries
Do NOT
forget to allow for 30% of input charge essentially non usable ie must charge 130% to get 100% out. What this means is power supply must be 30% larger or has to run 30% more time.

Dan Bentler

Ok Dan, You've Got me on that last post...What is the cause of the 30% loss? Is that a continuing loss factor, or just on the first start-up of the system?

I am guessing that it has to do with the internal resistance of the batteries, which would make it a continuing loss factor. So I would be better of using a tracking type mount to maximize the length of time that the panels will be actively collecting power.

Has anyone tried using Super Caps instead of Batteries for these types of applications? I would think that they have many advantages over batteries...much longer cycle life, lower self discharge rates, better temperature range, and less chance of damage due to severe and complete discharge.

Input, I need more Input.....

David

Dave

First it was just something I observed when a submarine battery charge electrician who also kept the battery log. I recorded all the charge data and the test discharge data.

We floated the battery between charges with a 5 amp discharge. This was a nuc submarine battery and was intended only for times when we had no shorepower or when we had a reactor scram so you could loosely call it a UPS. So if I counted the hours from last charge and multiplied by 5 I had an estimate of Ah out. Not a good one but an estimate.

For a year two I noticed that it seemed we always had to put more in than we took out. We could fairly accurate record amps amp hours in but did not have accurate recording of amp hrs out - we did not trust our ampere hour meter. The only real confirmation of 30% I had was from a test discharge where I accurately controlled and recorded amps out and then accurately recorded amps in - it came out to be about 25 to 30% more amps charged back in than we took out.

Some of this can be justified by battery heating - it takes power to heat that lead. Another part can be justified by reversal of a chemical reaction part of which is sulfate reversal which is what you do on every charge. The rest I am not sure of and would myself have to consult a battery manufacturer to learn more.

If you go with batteries as a reserve I would grossly overestimate the power they need to supply ie total Kw and Kw hrs and then add 25 to 50% depending on how vital the equipment operation is. I would also series to the maximum voltage NEC allows.

If this is a really vital operation I would go with individual cells which will not only let you take gravities but also let you watch individual cell voltages. Cost more but that is what I have seen in several industrial and nuc plant batteries.

Super caps seem like the battery technology that will have no problems - always just around the corner. I am very respectful of contained battery energy BUT compared to a battery (mostly because of familiarity) am paranoid of capacitors they seem to have more snap and bigger arc than batteries but then I have never seen batteries intentionally shorted either. Myself I would avoid them until they have been proven and found reliable in like installations by SOMEONE ELSE.

I am a cheapskate when it comes to trying technology not proven in the field for at least two years. I am very interested in the lithium batteries but am waiting for everyone else to prove them reliable.

Dan Bentler

Very interesting Dan...I have been the support for a short on a 24 volt batt in India years ago...I got my class ring between the post and the bus frame... I still have my finger, but the ring vanished...I do not wear any jewelery at any time ( not even my wedding ring) now, and that finger is just not right. KY is opening a Li-Batt production lab just north of BG this year, I'll see if I can get us some good data on their units. BTW...I just got the results of a 30 day test on my digester from the USDA...Very nice bell curve on the gas production / tank...I am VERY happy.

David:beerchug: