|
|
Gsfrey
Registered Users
New Member
Posts:80
 |
| 07/05/2008 12:26 PM |
|
Brock,
Help me out with wattage per square footage. I think in terms of commercial applications, but residential limitations may restrict the ability to get ample wattage on the roof as well. So as much as wattage per hour is a concern, I think wattage per square foot is also an issue for me. I have the ability, in El Paso, to do a lot of flat roof installations visiually protected by parapets, so I can max out square footage in ways those limited to pitched roofs cannot and not worry about unsightly PV panels being seen from the street.
|
|
Greg Freyermuth
915-256-7563, Phone
GregFreyermuth@elp.rr.com, E-Mail |
|
|
Brock
Registered Users
Basic Member
Posts:444
|
| 07/07/2008 9:22 PM |
|
| A lot of the more "decorative" panels, the ones that look like shingles have a lower wattage per square foot, they also cost the most, typically about $8-10 a watt. Then you have the panels that looks dark blue or purple in color and look like smeared out crystals, they are more efficient per foot and cost the least, right now in the $3-5 range. And finally you have the panels that have the purple/blue circles on them, cut silicon wafers, they will get you the most wattage per square foot, but also cost a bit more, in the $4-6 range. The last two come in all sizes and are typically mounted in an aluminum frame. Both of these last two typically last 25 years or are guaranteed to 80% of their rating after 25 years. Both have been beating that performance wise. The thin film or flexible or decorative panels are usually rated for 10 years and don't hold up as well, those are typically the ones you see at places like Harbor Freight or on eBay a lot. |
|
Green Bay, WI. - 4 ton horizontal, 16k gallon indoor pool, 1.8kw solar PV setup, 3400 sq ft |
|
|
gregj
Registered Users
Basic Member
Posts:218
|
| 07/10/2008 11:38 AM |
|
Posted By Brock on 07/02/2008 4:32 PM
Panels are rated in watts per hour with a sun isolation of 1000 lumens per square meter or something like that, basically the sun a solar noon and straight above you (meaning your in a very low latitude in summer). Typically you will see 10-15% less than that in the US in summer at noon. Also as the sun tracks across the sky the power from the sun changes. I start off at 7:30 am with about 50 watts, and then at solar noon I hit the peak, about 600w, and then fall back off to about 50 watts at 7 pm. This is with a 625w array. As temperatures rise the wattage output falls, but in winter since the sun is so far off angle the lower temps still don't make up for it. Say on a sunny day in summer with a 10 mph wind I might see 625w, on a wind less day in full sun I might see 575 because of the heat on the panels.
I should really have watts per hour or W/hr in there, most people just shorten it to watts. Thanks Brock, that helps a lot. Do you have any ballpark figures for what a 625 watt panel might actually generate over the couse of a sunny summer day in Green Bay and over the course of a typical year taking into account weather. I'm guessing something on the order of 3.5 to 4.5 kwh over the course of a sunny Green Bay Summer day and maybe 650 to 800 kwh per year but am probably way off.
|
|
|
|
|
Brock
Registered Users
Basic Member
Posts:444
|
| 07/10/2008 5:50 PM |
|
My max this summer has been 3.8 kw/day. With our last system, 4 KC 125's or 500w I typically saw 2.6-3.0 in summer in winter on a good sunny day I saw 1 and ranged everywhere between. For the previous two years it made just about 500kw each year. I think this location has a better southern exposure; our last one got no sun until about 10am so I had them tilted south west. Now I am pretty much straight south.
But your guess is probably close, conservatively I would say the wattage of the array in kw for the year, hopefully more, but I haven’t seen less yet. |
|
Green Bay, WI. - 4 ton horizontal, 16k gallon indoor pool, 1.8kw solar PV setup, 3400 sq ft |
|
|
Brock
Registered Users
Basic Member
Posts:444
|
| 07/10/2008 5:55 PM |
|
I hadn't thought about it in year terms in a while, since we have time of use that off set $.21 / kw power so I generated a whopping $210 in the last two years, at that rate 10 years would be just about on, for the solar panels alone.
Then again my intention was grid backup, not generation. It was either spend the money on a battery backup with solar or a nice whole house genset. The genset would never payback and is noisy, consumes fuel that I would have to store (and rotate) and isn't as automatic or instantaneous. |
|
Green Bay, WI. - 4 ton horizontal, 16k gallon indoor pool, 1.8kw solar PV setup, 3400 sq ft |
|
|
gregj
Registered Users
Basic Member
Posts:218
|
| 07/11/2008 9:27 AM |
|
| That info is very helpful. We have low utility rates here (4.6 cents per kwh) so even $1/watt panels don't make sense yet. But our electric rates will no doubt rise to the point where $1/watt panels do make sense. I hope that's a long time from now but I know that it isn't. |
|
|
|
|
jndrader
Registered Users
New Member
Posts:1
|
| 08/27/2008 2:00 PM |
|
I wonder how soon these panels could be available for home use? Bigger fish to fry for them right now but a more economical panel for residential use would be nice. We hope to start contruction on a house in 2011, maybe sooner if the market rebounds, and I'd love to have a grid-tie system in place at a cost that pays back sooner than 20-30 years.
Here's to hoping! |
|
|
|
|
Brock
Registered Users
Basic Member
Posts:444
|
| 08/28/2008 12:14 PM |
|
| Straight grid tie systems (no battery backup) typically have paybacks of about 10 years, less if your further south and more if your further north. |
|
Green Bay, WI. - 4 ton horizontal, 16k gallon indoor pool, 1.8kw solar PV setup, 3400 sq ft |
|
|
TechGromit
Registered Users
Basic Member
Posts:450
|
| 09/02/2008 12:17 PM |
|
Posted By Brock on 08/28/2008 12:14 PM
Straight grid tie systems (no battery backup) typically have paybacks of about 10 years, less if your further south and more if your further north.
So your payback in Antarctica should be almost instantaneous, cant get any more south than that.
|
|
|
|
|
Jhuanger629
Registered Users
New Member
Posts:31
|
| 09/02/2008 4:58 PM |
|
wow, hi again everyone, i've been away from this forum for a while as work has been ramping up but I'm so glad to see how active and informative this thread has become!
Will any of you on the west coast be attending the West Coast Green event? |
|
|
|
|
Brock
Registered Users
Basic Member
Posts:444
|
| 09/02/2008 5:52 PM |
|
Posted By TechGromit on 09/02/2008 12:17 PM
So your payback in Antarctica should be almost instantaneous, cant get any more south than that.
Dang you almost made me shoot Pepsi out of my nose! LOL
I stand corrected. The closer you are to the equator the quicker the payback ;) |
|
Green Bay, WI. - 4 ton horizontal, 16k gallon indoor pool, 1.8kw solar PV setup, 3400 sq ft |
|
|
senecarr
Registered Users
Basic Member
Posts:211
|
| 09/25/2008 5:05 PM |
|
Posted By Brock on 09/02/2008 5:52 PM Posted By TechGromit on 09/02/2008 12:17 PM
So your payback in Antarctica should be almost instantaneous, cant get any more south than that.
Dang you almost made me shoot Pepsi out of my nose! LOL
I stand corrected. The closer you are to the equator the quicker the payback ;)
Oddly enough, he's actually right. Antartica during it's summer would run continuously and has a thinner than normal Ozone (the magnetic poles make the spots more vulnerable to atmospheric changes of the last century). You probably could get pretty good figures out of it, but what would you send it to? Not many penguins seem interest in buying air conditioners and refrigerators.
|
|
|
|
|
senecarr
Registered Users
Basic Member
Posts:211
|
| 09/25/2008 5:19 PM |
|
Posted By Brock on 06/24/2008 9:50 AM
I have had good luck with http://www.sunelec.com/ Admittedly they are a pain because you have to call and order and they don't take credit cards so I have to get a certified check. I have ordered from them twice with no problems either time. Right now they have four panels at $2.98 a watt. They typically have a bunch in the $3-$4 / watt range. On another forum I am on they say the current panels are made for about $1 per watt already, then you add in overhead, profit and shipping to the retailer and you in the $3 to $4 range.
I think the mark up thought is a misunderstanding. The $1 / watt figure includes markups for making a profit, not simply the cost of materials. Even if retailer markup was then 100%, you're still looking at $2 / watt, which makes a very fast break even point.
|
|
|
|
|
tlhfirelion
Registered Users
New Member
Posts:27
|
| 10/17/2008 7:59 PM |
|
Posted By Quantum on 02/04/2008 1:56 PM This is going to be thin-film CIGSSe manufactured by Aleo, a technology licensed from Johanna of SA. Aleo isn't talking about it yet, but CIGSSe has [i]no silicon[/i] (which is in short supply), it works even on cloudy days, and has the potential to exceed the efficiencies of monocrystalline at a fraction of the cost! Very promising. Finally, CIGSSe is entering production! ... although it will be a couple years before we can actually buy it. PowerGuard was going to sell them, but was bought by SunPower. I wanted to set up U.S. production here in WA, but couldn't raise the $7 million it would take. Daystar and NanoSolar are going to make CIGS, a slightly inferior technology not to be confused with CIGSSe. And I don't trust anything Red Chinese.
AWESOME!!!!!
|
|
|
|
|
GreginAlaska
Registered Users
New Member
Posts:11
|
| 02/17/2009 6:05 AM |
|
Posted By Quantum on 02/05/2008 1:03 PM
Jhuanger, Dr. Ovshinsky is very circumspect about his plans, after the debacle of licensing his NiMH technology to GM, which turned around and licensed it to an oil company, subsequently burying it.
...."
Really? Which oil company?
|
|
|
|
|
Alton
Registered Users
Advanced Member
Posts:662
|
| 02/17/2009 7:10 AM |
|
Which Oil Company?
Here is a hint: Google NiMH battery Chevron |
|
Alton C. Keown
Residential Designer and Construction Technology Consultant
Auburn, Alabama
E-mail: alton at auburn dot edu |
|
|
sindhu sati
Registered Users
New Member
Posts:3
|
| 04/09/2009 2:03 AM |
|
HI
am from India i want to give some information about solar systems?
Solar energy is the most important source of energy.Solar energy can also be used in electricity requirements.Solar Photovoltaic cells, solar radiation gets converted into DC electricity directly. solar energy mostly used in batteries
A solar system is ideal for urban areas where building codes prevent a wind turbine. Solar systems work when sunlight strikes a solar photovoltaic module.
Solar energy
solar system
wind turbine
|
|
|
|
|