Testing our Solar Panels

**bclemens** · 10-14-2020, 10:13 AM

We had a few suppliers come in and pitch their solar panels. I don't always trust reps who may have handicapped their competitors stuff, so we did our own.

Parameters:
We set up our 100w Go Power flex panel and a potential replacement.
We hooked them both up to their own AGM battery and their own Victron MPPT solar controller (so that we could track history).
Since the contender also claimed that their panel was wired in such a way so that it did not lose as much when shaded, we laid a 1x4 diagonally across each panel to see what that did.

Results are attached. Our current panel held its own, and while not a huge difference, it made the decision to stay with our current panel pretty easy.

SeaDog · 10-14-2020, 10:27 AM

This is the kind of stuff the solar techs live for nice comparison You have the go power what was the other panel?

**bclemens** · 10-14-2020, 10:29 AM

That was a Merlin panel. I think a long term, one year test would be the most thorough....but this at least dispelled any early claims.

FOURWHL · 10-14-2020, 11:22 AM

The comparison panel was flexible as well?

KRedburn · 10-14-2020, 12:25 PM

Quote:

Originally Posted by FOURWHL

The comparison panel was flexible as well?

good question.

If a mounted panel not flex, I know of 380 watt single panels. that would be a game changer.

**bclemens** · 10-14-2020, 01:24 PM

Quote:

Originally Posted by FOURWHL

The comparison panel was flexible as well?

yes

Worm43 · 10-14-2020, 03:56 PM

On my 2017 Go Power Flexible panel. I get tops 7 amps out of one flex panel and the other is shot. I would say durability is an issue. I would go with two hard panels.

**bclemens** · 10-14-2020, 04:09 PM

I have seen hard panels go out as well. I don't think a panel failure is indicative of the overall durability. There are lots of factors to weigh, including installation, weight, availability, etc. Almost all changes have unintended consequences (or affects, as consequences has a negative connotation"). In many cases you potentially trade one possible issue for another.

Having used different ones over the years, rigid panels have their pros and cons, just like flex panels. With the vast majority performing well, I am not in any hurry to change without long term testing and a history of hard data.

Nomore9-5 · 10-14-2020, 04:40 PM

Quote:

Originally Posted by bclemens

We had a few suppliers come in and pitch their solar panels. I don't always trust reps who may have handicapped their competitors stuff, so we did our own.

Parameters:

We set up our 100w Go Power flex panel and a potential replacement.

We hooked them both up to their own AGM battery and their own Victron MPPT solar controller (so that we could track history).

Since the contender also claimed that their panel was wired in such a way so that it did not lose as much when shaded, we laid a 1x4 diagonally across each panel to see what that did.

Results are attached. Our current panel held its own, and while not a huge difference, it made the decision to stay with our current panel pretty easy.

I recently found a short u tube video on how to test your charge controller to ensure it's charging mh batteries. I'm technically challenged so I can't send you link however I think you can find it as follows
https://altestore.com/store/

it was put out in 2016 and runs 4:42

Thought I 'd share

Daniel.mullins4 · 10-14-2020, 09:32 PM

Go with lithium battery, you will get the most ah from your solar panels, lead acid and gel do not charge to 100%, your solar panel will only put out what is called for by the battery charge state, and what other devices you are using at the time

FFred · 10-15-2020, 05:46 AM

The solar panel sales folks always want to point to the high noon direct sunlight output of their units.

Great for houses , but almost every RV parks in the shade when they can

The output in shaded conditions is far more important than high noon .

Whalenss · 10-15-2020, 06:47 AM

Thanks for sharing test data. I like data driven decisions and that you continue to evaluate new products.

**bclemens** · 10-15-2020, 10:58 AM

Attached is a short paper my EE sent that just talks about the Maximum Power Point. Adds some info to the MPPT controller.

V6TOY4X · 10-15-2020, 11:47 PM

Just don't see this kind of inside look with any other manufacturer.

thanks!

**bclemens** · 10-16-2020, 08:23 AM

Quote:

Originally Posted by V6TOY4X

Just don't see this kind of inside look with any other manufacturer.

thanks!

Sometimes, I wonder if we give our competitors too much access to information. But I have always said...if you are copying, you will forever be behind.

TrailWayz · 10-16-2020, 08:32 AM

Quote:

Originally Posted by bclemens

But I have always said...if you are copying, you will forever be behind.

We saw a brand new Renegade Verona at our campground last week that was eerily similar to the Dynamax paint scheme. Until we got close I thought it was just a custom color order.

FOURWHL · 10-16-2020, 09:18 AM

Quote:

Originally Posted by bclemens

Sometimes, I wonder if we give our competitors too much access to information. But I have always said...if you are copying, you will forever be behind.

Not a direct comparison, but in my work in engineering we often worried about that as I was in niche fields. As it turns out it takes a lot more than a set of bootleg plans (or in this case forum post) to successfully execute a design. When you don't understand the underlying design decisions and philosophy, the details really aren't of much use.

Good on ya for keeping as open as you are! If you're constantly evolving they'll never catch ya.

jimmoore13 · 10-19-2020, 10:25 PM

Curious. After your test, did you mount the two in parallel so you have 200 watts. Should not pose a problem.

sconnors11 · 10-22-2020, 02:57 PM

I've been using rigid house panels on my RVs/Trailers for about a decade with good results. It's hard to beat the $/Watt and Watt/sq ft of a decent rigid panel.

We do a lot of Winter dry camping in the desert. The previous 1kW setup was just fine for most of the year, but couldn't keep up in the winter. I just finished updating my solar to the REC 330 NP panels. I was able to get five of them on the roof with fewer shading concerns than the older, larger Canadian Solar panels I was using. The REC 330 Watt panel is 66" x 40" compared to 77" by 39", which allowed two more to fit on the roof behind the air conditioner. The 60% increase should handle Winter just fine and I'll use the extra summer energy to charge the car.

I use the Morningstar Tristar 60 MPPT charge controller. These are built by electrical engineers like tanks, not copied from an existing design, and have really good efficiency. There are no moving parts and they don't mind an oversized array. I'm able to charge 60 amps into 24V batteries for 1,440 Watts max into the batteries.

I know the average Joe doesn't want/need a solar setup like mine, it's just hard for an engineer to resist...

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