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targis58 Samba Member
Joined: July 11, 2006 Posts: 539 Location: sunnyvale,ca
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gl98115 Samba Member
Joined: April 22, 2011 Posts: 263 Location: Seattle, WA
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PDXWesty Samba Member
Joined: April 11, 2006 Posts: 6234 Location: Portland OR
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Posted: Fri Dec 16, 2011 2:07 pm Post subject: |
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That's a killer deal and the panel is smaller than I've seen for 100 watts. I wouldn't hesitate to buy it. _________________ 89 Westy 2.1 Auto |
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WAgrower Samba Member
Joined: March 25, 2011 Posts: 182 Location: Seattle
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Posted: Fri Dec 16, 2011 5:34 pm Post subject: |
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Grape PV panels are low-end generic Chinese panels that are distributed from Eugene Oregon.
Where as that is a killer deal for 100W, you should buy with caution! _________________ 82' Westy running on WVO!
"We have created a market that socializes losses and privatizes gains" |
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WandS Samba Member
Joined: January 05, 2007 Posts: 228 Location: Miami, Florida
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Posted: Wed Dec 21, 2011 10:40 am Post subject: |
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What is the most common size and wattage everyone seems to use? I think i have heard the name kyocera a few times. I wonder if it would ever be worth for me as i carry a roof top box on one side and surfboards on the other. No real place to put it unless i make some slide out tracks going perpendicular to the van on the roof. _________________ 85 Westy Weekender with a Bostig Conversion. |
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windnsea Samba Member
Joined: May 07, 2008 Posts: 424 Location: Pasadena, CA
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Posted: Wed Dec 21, 2011 1:00 pm Post subject: |
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What is the voltage?? You'll probably also need converter to step it down to 12 volts.
It's easy to say 100 watts, but at what voltage?
... just a heads up. |
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WAgrower Samba Member
Joined: March 25, 2011 Posts: 182 Location: Seattle
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Posted: Wed Dec 21, 2011 11:39 pm Post subject: |
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Wattages depend on what your looking for the panel to do; most people tend to go with at least 150w to be effective.
As for the voltage; most any panel you get will be 12v. Other voltages are available but 12 is by far the most common for a cell.
Most people also find they prefer to have the panel on a portable rack so they don't have to park the van in the sun and allows for some solar tracking. Also deters theft. _________________ 82' Westy running on WVO!
"We have created a market that socializes losses and privatizes gains" |
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PDXWesty Samba Member
Joined: April 11, 2006 Posts: 6234 Location: Portland OR
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Posted: Thu Dec 22, 2011 9:58 am Post subject: |
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windnsea wrote: |
What is the voltage?? You'll probably also need converter to step it down to 12 volts.
It's easy to say 100 watts, but at what voltage?
... just a heads up. |
Watts don't vary based on voltage, amperes do. 100 watts is 100 watts regardless of the voltage.
Watts is power calculated by the formula: Watts = volts * amps _________________ 89 Westy 2.1 Auto |
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squeegee_boy Samba Member
Joined: April 27, 2008 Posts: 758 Location: Langley, BC, Canada
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Posted: Thu Dec 22, 2011 10:13 am Post subject: |
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windnsea wrote: |
What is the voltage?? You'll probably also need converter to step it down to 12 volts.
It's easy to say 100 watts, but at what voltage?
... just a heads up. |
That's what a charge controller does, which isn't included with the Costco panel. A charge controller will be needed no matter what, but can come from quite a few other sources.
For the curious, here's the spec sheet:
http://www.costco.com/images/content/misc/pdf/589846.pdf
The panel is rated at 18Vmpp.
Robyn _________________ 1984 FrankenSyncro Westy. EJ25 RMW kit
1971 Super Beetle with an EJ22. Oh yes. Daily driver |
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RBEmerson Samba Member
Joined: November 05, 2011 Posts: 2108 Location: SE PA
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Posted: Thu Dec 22, 2011 3:51 pm Post subject: |
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Look at Voc - 21VDC. Not much headroom for an MPPT controller to work with (basically a DC-DC converter that "fools" the panel into working at maximum output possible for the illumination and temperature conditions). The specs fail to mention the cell crystal type (probably not monocrystaline, probably polycrystaline, hopefully not amorphous - goes to potential efficiency) and how many diodes are used, to say nothing about how the cells are wired, to keep shadows from shutting the panel down. Frankly, a 100 watt panel isn't going to do a lot for you unless it's facing the sun squarely all day long. And even then, an MPPT controller is a must to get the most out of the panel.
IMHO, save your money for a real panel. And still be prepared for poor output unless you, literally, stay out of the shadows. _________________ Lord, give me coffee to change the things I can change, and wine to accept the things I can't change. |
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squeegee_boy Samba Member
Joined: April 27, 2008 Posts: 758 Location: Langley, BC, Canada
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Posted: Thu Dec 22, 2011 5:32 pm Post subject: |
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From the product description, in large type on the first link:
$249.99 after $30 OFF
Grape Solar High-Efficiency
100 Watt Off-Grid Monocrystalline PV Solar Panel
And it's on the upper right of the spec sheet, also in large type.
Robyn _________________ 1984 FrankenSyncro Westy. EJ25 RMW kit
1971 Super Beetle with an EJ22. Oh yes. Daily driver |
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targis58 Samba Member
Joined: July 11, 2006 Posts: 539 Location: sunnyvale,ca
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Posted: Thu Dec 22, 2011 8:37 pm Post subject: |
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Maybe a 100w panel is small for me...
If I get a fixed solar panel setup on my roof, I would like to be able to
1. use a 700w electric pot to boil water AND keep the water hot
2. use a laptop and a fold down dvd palyer at the same time
3. but still not under DIRECT sunlight
4. EDiT: hehe. Forgot about edge star 43qt freezer
Am I asking for too much?
P.S. I would prefer NOT to use the detachable kind panel...too lazy... _________________ 90 westy 2wd w/ TBD
Last edited by targis58 on Thu Dec 22, 2011 11:07 pm; edited 1 time in total |
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whafalia Samba Member
Joined: January 28, 2009 Posts: 685 Location: San Francisco
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Posted: Thu Dec 22, 2011 9:14 pm Post subject: |
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A lot of folks here poo-poo anything that doesn't run everything always, my intent is to have a compressor fridge and start with the batteries, I've a pair of surplus telco batteries I got off craigslist that should be good for 120ah, we'll see how that works. We don't tend to stay in one place more than 3-4 days without driving, usually less. If I get a panel that only supplies half my need it doubles my time, no? A smaller panel is more convenient and if I've run out of power for the fridge after 4-5 days I'm probably out of food too and am going to have to drive to the store to fill the fridge, maybe I'll do some battery charging while I'm at it! If the store is within walking distance I'm probably plugged into 110 anyway. |
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RBEmerson Samba Member
Joined: November 05, 2011 Posts: 2108 Location: SE PA
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Posted: Fri Dec 23, 2011 8:32 am Post subject: |
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squeegee_boy wrote: |
From the product description, in large type on the first link:
$249.99 after $30 OFF
Grape Solar High-Efficiency
100 Watt Off-Grid Monocrystalline PV Solar Panel
And it's on the upper right of the spec sheet, also in large type.
Robyn |
Sigh... I jumped right for the spec sheet stuff as most headlines are just that. Thanks for catching that point.
FWIW, monocrystaline cells are more efficient electrically, but are more expensive (each cell is made from a single silicon crystal - getting a good crystal out of a production batch has inherent costs from waste and rejections) per watt. Ya pays yer money, ya takes yer choice.
On the matter of a 700w load from a 100w panel... not quite. And the laptop and DVD at the same time? Maybe, maybe not (large screen backlighting and DVD drive motors eat power as do hard drives - think about an SSD to avoid that issue). At best, your panel is likely to only slow down the rate at which the house battery loses its charge.
Understand that 100w rating assumes the sun is directly over the panel (i.e., sun's rays are perpendicular to the panel). And that only on a cloudless day. Anything less than that, and the panel hasn't a hope of developing its full rated output. _________________ Lord, give me coffee to change the things I can change, and wine to accept the things I can't change. |
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j_dirge Samba Member
Joined: August 08, 2007 Posts: 4641 Location: Twain Harte, CA
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Posted: Fri Dec 23, 2011 9:16 am Post subject: |
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Can you say "doublespeak"?
From Grape Solar's website:
Quote: |
WARRANTY
Because Grape Solar products are manufactured by over thirty different factories around the world we have established a blanket warranty that is backed by the original equipment manufacturer’s warrantees. If Grape Solar disappeared tomorrow, your panels would still be covered by a warranty. |
Translation.. GrapeSolar is a reseller. We do not manufacture anything and we will push anything we can get our hands on as long as WE can turn a profit.
"30 different factories"?
Translation..
We have no QA/QC beyond a spec sheet and balance sheet.
Buyer Beware. _________________ -89 GL Westy, SVX.. finally.
-57 pan f/g buggy with a 67 pancake Type 3 "S"
"Jimi Hendrix owned one. Richard Nixon did not"
-Grand Tour, Season 1, episodes 4 and 5
danfromsyr wrote: |
those are straight line runs with light weight race cars for only 1/4mile at a time..
not pushing a loaded brick up a mountain pass with a family of 4+ inside expecting to have an event free vacation..
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Last edited by j_dirge on Sat Dec 24, 2011 8:52 am; edited 1 time in total |
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RBEmerson Samba Member
Joined: November 05, 2011 Posts: 2108 Location: SE PA
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Posted: Fri Dec 23, 2011 2:12 pm Post subject: |
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I suspect that's closer to "any of thirty different sources had their hand in the panels we supply - some come from supplier #1, some from #2, ... some from #nn". NTL, that's a strong reason to walk away from this panel. If the supplier said "Kyocera", or "Sanyo", or "Siemens", or... that's one thing. But "pick the source from thirty possible names?" Pass.
Unfortunately, the solar world is full of these sorts of "deals". Some come from sharks, some from the clueless; either way, the consumer gets to pay the freight. _________________ Lord, give me coffee to change the things I can change, and wine to accept the things I can't change. |
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PDXWesty Samba Member
Joined: April 11, 2006 Posts: 6234 Location: Portland OR
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Posted: Sat Dec 24, 2011 4:20 pm Post subject: |
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RBE you're way off base here. 100 watts is plenty to keep an aux battery system charged in a van. Solar panels aren't meant to power anything directly. You can run a 700 watt kettle and anything else you want. Also I don't think you can put down the quality of this product without seeing it. You definitely would want to use a higher voltage panel in a large array for a commercial installation to keep voltage loss down, but when engineering a small 12 volt system without inverters, this is an excellent choice for both quality, size, and power. You don't need anything more for the amount it will be used or for what it is powering. Don't be such a snob. The days of the $1200 solar panel are gone now that mass production has increased all over the world. Get started with something like this and you'll be a very happy camper. _________________ 89 Westy 2.1 Auto |
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rubbachicken Samba Member
Joined: October 05, 2004 Posts: 3058 Location: socal
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Posted: Sat Dec 24, 2011 6:57 pm Post subject: |
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PDXWesty wrote: |
RBE you're way off base here. 100 watts is plenty to keep an aux battery system charged in a van. Solar panels aren't meant to power anything directly. You can run a 700 watt kettle and anything else you want. Also I don't think you can put down the quality of this product without seeing it. . |
also think about our alternator, what's that 90 amp if you are lucky
i relies that the amps from the alternator will be more than from the solar cell
shame we can't afford one , our aux battery goes flat daily
from just the cooler box _________________ lucy our westy
lucy's BIG adventure
meet 'burni'
markswagen {mobile mechanic} san diego area all early VW's cared for.
619 201 0310 or 617 935 4182 |
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targis58 Samba Member
Joined: July 11, 2006 Posts: 539 Location: sunnyvale,ca
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Posted: Sun Dec 25, 2011 9:56 am Post subject: |
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Where do you find proper brackets to mount this on Thule bar?
I am thinking of mounting a panel under the bars, but not on the roof, so I still have room to carry something if need to... Bad idea? _________________ 90 westy 2wd w/ TBD |
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RBEmerson Samba Member
Joined: November 05, 2011 Posts: 2108 Location: SE PA
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Posted: Sun Dec 25, 2011 10:20 am Post subject: |
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PDXWesty wrote: |
RBE you're way off base here. 100 watts is plenty to keep an aux battery system charged in a van. Solar panels aren't meant to power anything directly. You can run a 700 watt kettle and anything else you want. Also I don't think you can put down the quality of this product without seeing it. You definitely would want to use a higher voltage panel in a large array for a commercial installation to keep voltage loss down, but when engineering a small 12 volt system without inverters, this is an excellent choice for both quality, size, and power. You don't need anything more for the amount it will be used or for what it is powering. Don't be such a snob. The days of the $1200 solar panel are gone now that mass production has increased all over the world. Get started with something like this and you'll be a very happy camper. |
I stand by my comments. I get that uses in a land vehicle are different than land "off the grid" uses or marine uses. NTL, the basics still obtain. A 100w panel sitting on top of a Westy simply cannot do much more than slow down the discharge rate for a battery that fits under the driver's seat in a Westy. This has nothing to do with the panel in question being Costco special (my personal opinion is there are far more cost effective sources). It goes back to the rules of electricity and the physics of photocells. Argue with them if you must (don't hold your breath waiting for a change, though). _________________ Lord, give me coffee to change the things I can change, and wine to accept the things I can't change. |
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