Solar Panel - 2x Batteries - National Luna Fridge

[george]

Something is wrong....

I only run a 60 watt panel and when connected, and panel is in the sun, I can clearly see it on the NL bat monitor as it will show a voltage increase of about 3 led's.

I'll also run some tests and share the results...

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jis Jaco
What happens when the panel is in the shade?Does it produce less power or no power

[Royco]

I think the problem is the position of the panel.

Quoted from various websites:
The output of any panel will be reduced or cut off if shaded.
The mono-crystalline solar panels are somewhat more shade tolerant than poly-crystalline solar panels because each cell cuts out only when totally shaded. (emphasis added)

Check out this site: http://www.renewableenergyworld.com/rea ... pens-54551" onclick="window.open(this.href);return false;

I don't quite get this table, as the more shade the more voltage output !?!?

But it does show that a small amount of shade can reduce the output by around 50%.

I'll also run some tests and share the results...

It would be great to see your tests, Jaco.

[SuidWes]

Shade is a problem even if you cover only one cell.....

Will do some tests on that as well

[SuidWes]

OK, so as promised I've started testing.

Quite a mission to remove everything from the SFA :alvarin: Anyway, decided to place the panel on the balcony where it can get about 8 hours of direct sun per day. Note pro stand

Setup Detail:

102 ah Exide High Cycle battery (2yrs old)
Steca Solsum 6.6c controller
55 Watt (3.1Amp) Tenesol Panel (1yr old)
40 Engel (5yrs old)

For the first test I also left the freezer empty and I set it to setting 2 which keep the inside temp between -3 and -5 degrees according to the Engel temp display.

Results:

Date Time Bat Voltage Temp Weather
23/02 19:30 12.81 -4 N/A
24/02 06:00 12.50 -5 Sunny
24/02 19:30 12.61 -5 N/A
25/02 06:00 12.41 -4 Rain to 10:00 AM; Sunny for the rest
25/02 19:30 12.55 -5 N/A
26/02 06:00 12.32 -4 Cloudy
26/02 19:30 12.47 -4 N/A
27/02 06:00 12.23 -5 Cloudy for most
27/02 19:30 12.27 -4 N/A

I’ll keep going till the battery gets to 12.2 Volt (50% SoC) Then charge it again for test 2

[SuidWes]

Now the Shade Question:

I quickly removed the freezer for this test.

Panel covered after 5 mins = 12.35V
No cover after 2 mins = 12.78V
1/2 cover after 2 mins = 12.46V
1/4 cover after 2 mins = 12.56V

So direct sun with no shade is extremely important.

jis Jaco
What happens when the panel is in the shade?Does it produce less power or no power

George, less power much less

[SuidWes]

OK, on day 4 and think we might make it to the end of Day 5.....

See attached graph showing the results so far for test 1.

I will fill the freezer for test 2, open it twice a day and cool some beers daily as well Should be interesting :arrow:

[SuidWes]

Due to cloudy weather we did not make day 5 :| Latest results attached.

I'm now going to recharge the battery and put the fridge on 220... Will start with the 2nd test on Tuesday

[george]

Nice one Jaco. Good to get some real life data.
it would be nice if to see how a 90 watt will operate on the same conditions

[SuidWes]

Think a 90 watt would have topped up the battery every day... :arrow: