| Author |
Message |
Nick Morris (Nick3751)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, August 30, 2005 - 2:52 pm: | |
Been a while folks but I've been poorer than normal. Not that that has changed but I'm trying to get a clue as to how much pannel I'm going to need on my rig. I'm looking at enough room for about 8 T-105s to run a basement air, fridge, tv, etc. etc. Of course it all may or may not be on all the time and the genny will be run through a trace SW series inverter or two to help when need be. That being the case I'd rather have to use the genny to run a buddys coach or for ballast than for power all I can. So with a worst case senario how much power will I need to replace with my pannels to keep my bats up to par.
I suppose I could go hunt this info up and figure it out but I hate doing work twice and I bet someone here either knows the formula I need by memory or has it wrote down somewhere handy.
Thanks guys. |
David Hartley (Drdave)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, August 30, 2005 - 3:12 pm: | |
Depends on the square footage of available roof and square footage of your budget. My 100 watt panels take up about 6 feet X 24 inches each.
I would like to have 10 panels but at $800 each (retail) I don't see any budget for $8,000 to sit on the roof for 1,000 watts (peak) battery charging.
Solar prices are slowly coming down but unless they can pack more power into a smaller panel it will be some time before an air conditioed coach will be able to depend on solar as a reliable source of primary power.
The smallest window shaker that I have found still pulls 750 watts @120 volts for 5,000 btu.
that's about 75 amps @ 12 volts plus losses through conversion. a 24 volt system might be a little better but what about your interior lighting? Most people use 12 volt RV fixtures.
Spend that money on a super quiet diesel generator and soundproofing system or wait for the PEM fuel cells to finally hit the rv market that uses diesel and air to make electricity to run a big inverter and produce extra hot water. The claims are looking at 95% efficiency for the rv units when they become available. |
Tim Hoskinson (Tdh37514151)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, August 30, 2005 - 7:37 pm: | |
Hey Nick how have you been? I have had some computer problems and at present have no e mail. Have you got the 3751 any farther along? I am still working on both my 4104 and my 3751 modified. Best of luck to you Nick. Tim |
Nick Morris (Nick3751)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, August 30, 2005 - 10:15 pm: | |
What I'm hoping for is a big enough bat bank and solar pannels to run what I need during the day then run the genny in the evening when cooking to charge bats for the night. Of course like I said I'll have the gen to help with the a/c and other loads. As far as lighting goes I like gumpy's led's lots of light and just a little juice. |
CoryDane
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, August 30, 2005 - 11:23 pm: | |
Well Panels come in different sizes....
64 watt is pretty common but there are larger available.
at 24vdc, two 64watt panels (128watts) would supply roughly 5 amps, at high sun, no shade, no clouds.
5amps at 24vdc would roughly translate to 1 amp 120vac. Actually less with the losses of conversion.
I think I have that right so far.
SO if you have a 15 amp air con, you would need more than 15 panels (you have to account for start up currents) plus whatever else you will be running. You would also need all the roof space you can cover with solar panels. But you must also account for cloudy days, or shade, where the current production would be only 25% or less.
Do you get the feeling that this may not be the most optimum idea???
AC is not even recommended to be run from the batteries on an inverter. Just not enough battery storage energy.
the standing rule on the board is, solar can not run AC. In most cases, Solar is widely used to recharge the batts, and little else.
As far as LEDS go, if you are planning to flood the room with light, look at floresent, an LED can't do it.
They will be dark for even reading and the light is a very tight pattern, Perhaps a loose LED light is good for map reading.
You need to realize there is a cost to saving power, and with LED, the cost is usable light. They are good for night lights or lighting a close area such as under cabinets or on a table top, or even to sight across the floor/carpet.
A candle will share more light in a room than an LED can provide. Test it for yourself, you will prove it to yourself.
You need to use LEDs for their intended purpose, lighting a room won't cut it.
West Marine sells a med screw in type bult that operates at 12vdc, using only 15watts. Might look into this alternative.
Good luck with your endeavour |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 31, 2005 - 12:47 am: | |
Rat Shack's "grain of wheat" bulbs run 12 vdc and take little power.
I ran a bunch of them in both the Winnie and Georgie-boy RVs, by
connecting the leads to a broken bulb base. We could leave the
interior lights (and exterior marker lights) on all night, and still be
able to start the engine at 9am.
LEDs aren't the only option! |
Tim Strommen (Tim_strommen)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 31, 2005 - 2:04 am: | |
I figure I should stand on the side of LEDs as they seem to be lonely in this post...
Check these Luxeon LEDs out.
These are being used by most manufacturers for new high-intensity LED designs. They can be found in the new "Super-bright" single-LED flashlights, the new $13,000 Sony Qualia LCD backlight, Toyota's new tail-light (only one LED replaces the old 1157!), the Audi A8 as a DRL, and a new aftermarket design uses the next level up from this model as a -->lowbeam replacement<--. Combine this with some of the 3M light-pipe film and you have a single ended "florescent like" tube that can be several FEET long. These Luxeon III LEDs can offer 80 lumens in white (more in color) which is the same as about 8 of the brightest T1-3/4 base LEDs available (for only twice the price of one T1-3/4 LED).
Currently they support two beam patterns:
1) "Lambertian" - This is a roughly 110 degree beam pattern desinged for direct lighting with collaminating optics and lenses (think "spotlight" or "floodlight" here).
2) "Side Emitting" - This is a roughly 40 degree beam pattern that emits around the entire LED and is used for either a 360 narrow beam lightsource (think navigation beacon here) or very thin reflector optics (think 2 inch thick 2 foot square diffused ceiling light)
For those who are motivated to try a few of these, I'm aware of only one distributor in North America (yes, this includes you too Canada!) They are Future Electronics, and can be found HERE.
Philips is trying to buy Agilent's interest out of this company, so we should be seeing LEDs that put out as much light as an H1 bulb within a year. Stay tuned...
Cheers!
Tim
P.S. There are three things I should warn about these LEDs:
1) These are essentially "LASER" levels of light and should not be looked at without diffusion optics or eye protection! (I think I still have a dark spot from the lower power LED a few days ago...)
2) These things deal with voltage in >>AMPS<<!!!! No meager milliamps anymore!
3) Heatsinks... Heatsinks... Heatsinks... You have a three watt heater here.
-T |
FAST FRED
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 31, 2005 - 5:54 am: | |
"What I'm hoping for is a big enough bat bank and solar pannels to run what I need during the day then run the genny in the evening when cooking to charge bats for the night."
Even if you entirly cover the coach roof it will be almost impossable to create enough electric to run a 25,ooobtu air cond.
Charging up a bat set in a couple of hours a nite is also impossable , as the last 10% takes a very long time, many hours AFTER the first 90% is restored.
Check out glacierbay.com for usefull info on what bat sets can do.
FAST FRED |
Jim Stewart (H3jim)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 31, 2005 - 10:54 am: | |
I too am seriously looking at solar. I have a 13k gnerator, in a quiet box. I am thinking I can get 700 watts up there, between the air-conditioners and my roof deck. I have about 600 amp hours at 24 volts of battery bank. If I need to run the airs, I will be using the generator, period.
My reason for looking at solar is to get that final 10% of charge on a regular basis. I boondock a lot. I think it will make my expensive batteries last longer, being more fully charged on a regular basis. I also think that when I don't need to run the airs, that I won't need to run the genset every day which is a plus. For a genset, its quiet, but nothing is as quiet as solar. That total independance (sans air-conditioning)is what I think solar will do for me. |
Jim (Jim_in_california)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 31, 2005 - 12:08 pm: | |
Jim Stewart has it about right.
Enough solar gear (400+ watts with a quality MPPT solar control and decent inverter and battery) will run most people's computer gear, home electronics and the like.
One trick I think most people are missing is "how do you get your aircon(s) running with the absolute minimum size genset possible for max fuel efficiency"?
Example: if I use my Outback VFX2812 inverter to start my air conditioner (13.5k) in my main living area, let it get going for about five minutes, crank the aircon to max so it doesn't cycle, I should be able to start up a little Honda EU2000i and let it run the aircon. I would then turn off the Outback's charger function, let the aircon run off the gennie, run my computer gear off battery power which has 660w of solar panel still on tap.
I've essentially cut my whole system in half. And that little Honda can go practically all day on a gallon of gas. If my boondocking costs with aircon are only in the $3/day range, I'm plenty happy.
Now when Outback finishes that "generator support" ROM upgrade where it'll supplement generator-supplied AC110v with inverter-based power for startup loads, then I'll really be cookin'. I'll be able to let the aircon cycle normally if I want.
This is supposed to be "coming soon" for the FX/VFX inverters in the form of a flashable update.
Upshot: solar isn't the whole answer. It's a big part though; the rest involves using less generator than we've previously been doing.
Even the guys with 50amp wiring and dual 15k aircons may be able to get away with a 5kw or 6kw Diesel genset. The guys with 30amp service and one aircon may be able to drop down to the 2kw - 2.4kw (Honda and Yamaha ultraquiet models respectively). |
|