peak hours

[miike012]

I am having difficulty understanding the information. Maybe some one can help me.

This program calculates the peak hours for my location. Should I only focus on the info that I highlighted in red??

[andrewc]

I'm not sure if it would be better if you simply created a single thread for all your concerns, as opposed to making a new thread with every question you come up with. But with that said...

The number that is most significant would be the one that corresponds to the tilt of your array. As you can see from the various tilt rows, these numbers change based on the angle of your panels. The first row (that you have with a red square around the last column) I believe is assuming a horizontal surface, or zero degree tilt. And I think it is using the worst months out of the 22 year sample period to give you a baseline minimum expectation.

Also, keep in mind that the chart is based on "an equator-pointed" surface, which I think means it is assuming a 180 degree azimuth (due south) in the Northern Hemisphere. In the real world, your array may not be able to be angled in that exact direction.

With that said, I'm not sure what you don't understand exactly, and what you are trying to accomplish. If you are more specific, I might be able to help out further. Also, PVWatts is a common online tool used for annual insolation and production estimation. via nrel.gov

[russ]

Try using PV Watts http://mapserve3.nrel.gov/PVWatts_Viewer/index.html

We all know this program.

[epsgunner]

Try using PV Watts http://mapserve3.nrel.gov/PVWatts_Viewer/index.html

We all know this program.

I'll ask the dumb question..

If my NAMEPLATE panel total is 725 (145*5) watts.. do I put .725 in the DC Rating (kW) entry??

Or do I put the total of 5 hours * 725 in that entry??

[inetdog]

Entry into PV Watts

I'll ask the dumb question..

If my NAMEPLATE panel total is 725 (145*5) watts.. do I put .725 in the DC Rating (kW) entry??

Or do I put the total of 5 hours * 725 in that entry??

Since it asks for kW, rather than kWH, you put in just the .725 figure. The program will calculate the total power (based on sun hours for your location) that the panel will produce.

[epsgunner]

Thanks.. I'm at 30.69 lat. on my TX property (where panels will be) facing directly South.



As I figured.. Best summer is 15' angle for mid 7's radiance.. for 108-122 AC kw

Best overall is 26' angle.. (macslab was correct) 5-7.55 radiances..

Winter at 45' angle gets me mostly 6.XX's radiance..

[Wy_White_Wolf]

... Should I only focus on the info that I highlighted in red??

Depends on your system. Is this an off-grid system or a gridtied with net metering?

[russ]

I'll ask the dumb question..

If my NAMEPLATE panel total is 725 (145*5) watts.. do I put .725 in the DC Rating (kW) entry??

Or do I put the total of 5 hours * 725 in that entry??

You put 1 in as that is as low as the program will accept and then multiply the results by .725

[russ]

I used Austin and a 1 kW system for the following - 30

[Sunking]

Thanks.. I'm at 30.69 lat. on my TX property (where panels will be) facing directly South.

EPS if I remember correctly you have a Off-Grid Battery system right? If so unless you changed the efficiency to 50% then the PV Watts Data is invalid because its default is set for 77% for a Grid Tied system

[epsgunner]

You put 1 in as that is as low as the program will accept and then multiply the results by .725

It does take .725 for the KW.. just tried it.. numbers DO work the same as what you said if I did go that route..

Sunking.. thanks.. currently I get my 77% to my controller/battery (with testing I am doing)..

I'll knock it back abit, but not 52%.. my 3/0 wire 3.5 feet and 0.90 eff inverter should keep me at like 62-68% is my guess.. the current draw is like 0.8 amp at rest.

I just wanted to get the irradiance factors for the angles.. not the $ or AC KW numbers..

[Sunking]

Sunking.. thanks.. currently I get my 77% to my controller/battery (with testing I am doing)..

If you are speaking about from panel to output of controller then you have a problem. With wiring from the panels and controller losses you should be at less than 10% loss (4% for wiring and 5% for controller). You are claiming 23% loss or 77% efficient. If the panels are generating 100 watts, then at the output of a MPPT controller you should be seeing something like 90 to 93 watts to the batteries. There is a problem somewhere if you were only seeing 77 watts out of 100.

[epsgunner]

I'm unsure then I guess.

I have the Morningstar TS-45 PWM, and not the MPPT version..

My TriStar meter measures solar voltage from panels from a high of 16.39 V to a low of 14.39V..
(if I had the MPPT it would give me more information.. such as logged min/max volts and such)

The front screen for the battery numbers says about 14.8V 110w and 7.4 amps at 99% PWM..

Then its goes to BULK and 14.4V, 112w and 7.6 -7.8amps.

110w is 77% of the rated 145w sticker..

The AH meter said 16.2 AH for 2 hours..

Again I am unsure of what I have as I don't have an incoming WATT meter..

[epsgunner]

Outside playing with my dead (amp wise) battery.. its VERY cloudy and 83'F..

12.6V and 0 amps reading on the TS45 (with the PV array off).

I checked the TRUE solar volts after the combiner box at the controller.. 20.7V with a meter..

I then turn on the 1 panel 145w solar array with the breaker..

on the main battery screen I now get

12.9 V on the battery (and going up) and like 1.9 amps and 25 watts..

I get 13.2 V listed under that separate solar panel display area in diagnostics.

25 on the meter and 39.33 (20.7* same 1.9 Amps).

So it would appear I am loosing like 15 watts of difference of the panel input..

So simple math would be 145w (Rated) - 15 watts of spent watts based on these numbers.. = 130 watts..

I don't have any inverter yet to test draw down and such... and this BAKED battery isn't helping the matter..

[billvon]

on the main battery screen I now get 12.9 V on the battery (and going up) and like 1.9 amps and 25 watts . . . .

One thing I would strongly recommend - if you are doing efficiency measurements, get a GOOD volt/amp meter and use the same meter to make all four measurements (Vpanel, Ipanel, Vbatt, Ibatt.) Don't trust the voltages/currents shown on the screen of the controller. They are often there just to give a very rough sense of power delivered.