peak hours

[russ]

is is 1.72 kwh/(m^2-day) energy produced good, bad, or average?

Considering it is based on an imaginary consistent 1000 watts/m2 insolation it is meaningless.

1000 watts/m2 is not the most insolation a panel can accept - I do not know where that misconception comes from.

The annual average insolation for Phoenix is 5.35 watts/m2/day - on a fixed mount you may achieve 85% of that

[miike012]

I used a consistent 1000 w/m^2 because that is what the module was tested at.

[russ]

I used a consistent 1000 w/m^2 because that is what the module was tested at.

1000 watts/m2 is part of the STC (Standard Test Conditions) - by using STC or PTC any lab with the correct equipment can verify the panel production.

A typical June day at my location

0600 1 watt/m2
0700 25 watts/m2
0800 58 watts/m2
0900 151
1000 404
1100 711
1200 831
1300 906
1400 920
1500 879
1600 787
1700 650
1800 445
1900 275
2000 113
2100 11
2200 0
total 7,167 kW/m2/day

PTC conditions are much more real world - 800 watts/m2

[miike012]

where can i find info and stats on the affects of high temp. on solar panels?

[russ]

That information you already have. Look at the document I provided a link to in post no.25

Info and stats is a meaningless statement. You need only to how to temperature correct for a particular panel in question.

For an individual cell or a DIY panel one might spend a million bucks on equipment and still have a half assed idea.

[miike012]

Sorry I need to know what about correct temperature?

I'm finding it very hard to search for information on cells, I think it because I'm trying to do all this reasearch in a short amount of time which is making me rush.

Anyways this is the outline of what I will talk about during my speach

1. Efficiency of cell

I was going to compare the density, efficiency, Pmax, Ptolerance, cell type of a list of moduals.. (I will get this info from the data sheet- Is this useless info when comparing a modual?) Anyways I will finally lead into why I picked the sun tech solar cell explaining that I believe it is most efficient which I need due to limited roof space... To be honest I dont have much time so i will probably be doing a little bs'sing...

2nd I will compare prices of a few systems and the first annual savings-( i will get this info by calling the dealer)

3rd talk about where and why we decided to mount the pv system where we did, my parner and I did a project to decided this which we will talk about in our speach

I will also talk about suntech warranty and why thats important/ how much I save using suntech/ and incentives.. I will throw this in there somewhere
I know this isn't a perfect outline but this is what I have in a limited amount of time, what do you think?

[miike012]

Also you have to realize the way Im going to go about my speach, I am a new customer.. I have never purchased solar in my life and no nothing about solar so I will be looking at and comparing data sheets (just like any other customer I would imagine) .

[Naptown]

If you want high efficiency Suntech are not top of the line eficiency wise.
Look at Sanyo and Sunpower

[miike012]

I have a question about power of the module. Under STC my module says it is 333 watts but under PTC it says 247 Watts. My questions is, how is the power of the module determined?

thank you.

[Sunking]

I have a question about power of the module. Under STC my module says it is 333 watts but under PTC it says 247 Watts. My questions is, how is the power of the module determined?

thank you.

STC is strictly a lab measurement under very strict controlled conditions. PTC is 3rd party test results under real application.

PTC and/or/ ratings are used to qualify for state/federal/local incentives and SREC.

[Naptown]

I have a question about power of the module. Under STC my module says it is 333 watts but under PTC it says 247 Watts. My questions is, how is the power of the module determined?

thank you.

If that is the case yo got ripped off.
I will reject any module that PTC is less than 87% of STC without question.
that module is 74% of STC
Can you get your money back?
Most quality modules are in the 88-90+% range of PTC to STC

[Naptown]

STC is strictly a lab measurement under very strict controlled conditions. PTC is 3rd party test results under real application.

PTC and/or/ ratings are used to qualify for state/federal/local incentives and SREC.

This is also what PVwatts, Pathfinder and Solmetric Eye use to determine the annual output.

[andrewc]

My questions is, how is the power of the module determined?

Same way power is normally determined, Ohm's Law. Power is equal to amperage times voltage. The amperage of a solar cell is proportional to irradiance (exposure to the sun), and voltage is inversely proportional to temperature. The power output of a module changes constantly throughout the day as those conditions change. Angle of sun and cloud cover change irradiance, and the temperature goes up and down. However, there are a number of standard test conditions where manufactures can say their panel will produce X under certain specific conditions. This is what STC and SOC and PTC are, various conditions whose parameters determine the power output of a panel.

PTC is 3rd party test results under real application.

I think this should be qualified that PVUSA isn't physically testing every single panel themselves, but instead are applying a statistical model to the given parameters of a panel. Their parameters are intended to be more of a real world application than STC, but isn't actually a result of a real test. It's just maths. Some panel manufactures flash test their panels upon shipment, and include that data with the shipment, so you could have specific data for each individual panel, but perhaps that is getting a bit off topic.

[miike012]

the system that I have been looking at for my project is around 37000 dollars that includes installation and the 25 327 watt sunpower panels. After calculating the possible incentives the total cost is around 22000 dollars. My friend was doing some calculations and he is saying that we will never save any money. Can someone direct me to a site with incenctives for arizona? Im hopeing if I can save more money we will actually be able to save money.

[russ]

the system that I have been looking at for my project is around 37000 dollars that includes installation and the 25 327 watt sunpower panels. After calculating the possible incentives the total cost is around 22000 dollars. My friend was doing some calculations and he is saying that we will never save any money. Can someone direct me to a site with incenctives for arizona? Im hopeing if I can save more money we will actually be able to save money.

On the forum page - on the right side you will see a link titled 'federal & state incentves - same link as follows

http://www.dsireusa.org/

Then you click on Arizona