FYI on some solar panel sales

[LeishaShannon]

http://www.everythingcaravans.com.a...le-solar-panel-amorphous-foldable-heavy-duty/

They look like amorphous panels, terribly inefficient (a decent Sunpower/LG neon glass panel will produce 400% more energy from the same area)

At $12.60/watt they're also ridiculously expensive

 

[LeishaShannon]

The problem with these cheap per Watt 24V panels is that they are huge. As in, even if they fit in my roof (or whatever), they seem like they will break on the first hard bump that I hit...

If someone tries the big boys, they should report back!

We have 300W panels on our truck and have had no problems with bumps and vibrations so far. They're built to survive golf ball size hail storms and generally have much tougher glass/frames than the smaller panels. Your insurance would probably cover any serious damage if it did happen.

 

[G_fresh]

We have 300W panels on our truck and have had no problems with bumps and vibrations so far.

Good to know!

A single, 300W panel?

 

[LeishaShannon]

4 of them + 4 x 100W flexible panels for portable use. (We use -a lot- of power)

 

[IdaSHO]

God I guess! :Wow1:


That's 1600 watts of PV if I'm counting right....


I seemed to have run out of fingers and toes....

 

[teotwaki]

4 of them + 4 x 100W flexible panels for portable use. (We use -a lot- of power)

electrical system consists of :

360Ah @ 24v LYP Batteries
1500W of Solar (1200W of LG MonoX Neon on the roof , 300W "portable" for when we're parked in the shade)
150v / 70A Victron BlueSolar MPPT Controller (Backup controller still required, we're waiting for Victron's new 150/35)
2 x 1600VA Victron Multiplus Inverter/Chargers configured in parallel for redundancy
2 x 25A 24v to 12v DCDC converters in parallel for 12v loads configured in parallel for redundancy
Victron BMV-702 and Colour Control GX for monitoring and control of the entire power system

View attachment 225366

We're planning to have no gas/diesel appliances and doing everything using 240v appliances. So far we've got:

Samsung 255L inverter refrigerator (measured 23watts average load over a week)
2 x Single plate induction cooktops
Sheffield Convection Microwave Oven + Breadmaker + Grill Combo (We've been using this in our house for the past year and love it)
Mitsubishi Heavy Industries 2kw reverse cycle inverter AC (This unit is the most efficient we could find, draws a maximum of 350W and a 180W minimum)
24L Force10 Marine HWS (240v + hydronic, but we're not hooking up the hydronic side initially)

 

[FLEXOPOWER USA]

Know where to get these? I spent 5 minutes on the Google and couldn't find them for sale...

G-Fresh, they are available locally from https://www.flexopowerusa.com/

Regarding efficiency, the technology used is a-Si which has a lower efficiency than c-Si. However what matters is how much energy the panels produce in a given time frame. Efficiency is not the yard stick. Our a-Si triple junction deliver 15% more real energy than comparable glass panels (c-Si) during say 1 day. Partial shading is the next category where the Flexopower score over glass panels. We compared a 85W SolarWorld with a 79W Flexopower and covered 10% of its surface to simulate partial shading. SolarWorld measured -78% in output vs. Flexopower -12%. You can read up on our blog https://www.flexopowerusa.com/blogs/news

 

[LeishaShannon]

However what matters is how much energy the panels produce in a given time frame. Efficiency is not the yard stick.

I'd argue that for a lot of mobile users with limited space that energy produced per unit of area (Efficiency) is what matters. We have limited space on our roofs and need to make the most energy for a given area...

Our a-Si triple junction deliver 15% more real energy than glass panels (c-Si) during say 1 day.

Per rated watt... The problem for us is your panel will be 3x to 4x larger area to produce the same rated watts...

Partial shading is the next category where the Flexopower score over glass panels. We compared a 85W SolarWorld with a 79W Flexopower and covered 10% of its surface to simulate partial shading. SolarWorld measured -78% in output vs. Flexopower -12%.

This is where amorphous panels like yours really do "shine" , the bypass diodes on each cell allow the output to degrade gracefully as shade increases. However one point that may not be obvious is that because your panels are 3x bigger they're more likely to be in the shade than a smaller well positioned high output panel.

That said - for portable panels wouldn't you be putting them out in the direct sun? We use a 25m lead so even if we're parked in the shade the portable panels will be in full sun.

The other issue with really flexible panels like yours is its difficult to get them to face the sun so you'd generally deploy them flat on the ground. If we're relying on our portable panels I move and change the angle of them a few times a day to maximise the output:

As you can see moving the panels to face the sun a few times a day significantly improves the output.

This is easy with 105cm x 54cm relatively stiff panels that weigh 1.7Kg and produce 100W. Trying to do that with 4 300cm x 40cm "floppy" 79W panels that weigh twice as much would be... tricky.


If I parked in partial shade 95% of the time I could see where amorphous panels on the roof might be beneficial but for our use case they just don't make sense. On our roof we're much better served with high efficiency LG Neons producing 1200W using just 6.6m2 , rather than the 440W we'd get if we used amorphous panels. For portable use our light weight mono panels are lighter, easier to deploy, and 1/3 the size.

 

[FLEXOPOWER USA]

I'd argue that for a lot of mobile users with limited space that energy produced per unit of area (Efficiency) is what matters. We have limited space on our roofs and need to make the most energy for a given area...

Agreed for limited roof space c-Si lends itself.

 

[teotwaki]

If we had the luxury of space I would go with a 250W 24 volt panel and a MPPT controller to charge the 12v batteries.