Solar panels ....... rigid or flexible ?

Just wondered if anybody had any strong thoughts on this choice ?

Rigid, while looking a little clumsy, would be relatively easy to upgrade if required. I already have roof-bars, though they are not presently on the van.

A flexible panel would be pretty much invisible.

From the little reading I have done it seems that their is little or no difference in performance.

Not relevant to rigid or flexible, by my thinking is that panels need to face the sun directly to get maximum performance. If they're fixed to the van that can't be achieved without moving around throughout the day.

Solar panels need to be kept cool for best performance so rigid panels mounted with some clearance to allow airflow underneath will perform better than flexible panels directly on the roof. As the poster above said you will never get the rated maximum output from any panel which can't be re-positioned automatically to keep facing directly into the sun, I think if you halve the rating of the panel you'll probably get somewhere in the ballpark of what you'll actually get under normal conditions. Don't fall into the trap of thinking you'll have huge amounts of electrical energy available; you won't. Also remember to not let your deep cycle batteries run down much below 50% charge as that can shorten their life (and they're not cheap!) Use an MPPT controller, but beware of the very considerable radio interference radiated by many controllers on the market.

We have a flexible 130w panel glued to the roof, 2 years use now no problems at all, keeps the battery topped up, but struggles in the winter . At the end of the day its all about consumption do not think you can run a compressor fridge, use a 3way fridge led lights and a low wattage TV diesel night heater, we free camp mostly and have never run out of power.

@jt69 how many amp hours do you have battery wise?

Thanks for all the responses.

Having a panel I can fully orientate was a bit low down on my priorities given that if you are going to tilt it, then you need to be able to spin it as well.

Fairly common not to get a choice in precisely which direction you park and when you do the view will always come first.

Read in a few places that roughly you should consider 1 watt per amp.hr of the battery. So with a 115a.hr battery I'm going to go with a 150 panel to allow for in-efficiencies.

Decided to go with flexible as the roof bars I have look a little clumsy and this way the install will be virtually invisible. As for cooling of the panel when fixed directly to the roof, i was given a tip to use that corrugated plastic paneling and sandwich this between panel and leaving the front and rear edges clear to allow air to flow in between when driving.

Expected loads in the van will rarely exceed the 18 watt TV plus charging my devices (phone, BT speaker etc.). No real intention of getting a fridge as the cooler box seems to fit me needs.

My battery is 100amp hr and solar panel 130w , all I can say is it works well , over 2 years no problems.

Out of interest, care to offer any advice or tips for routing the cable from the roof ?

My panel is stuck on to the rear of the van roof cables also with adhesive feed through top left of rear door (drilling holes in the van roof is not a good idea) into door reassess then into interior part of frame with rubber grommet and sealant down inside door pillar to below bed level then to interior of van to regulator and to battery . I used Syckaflex adhesive sealant expensive but the best.

I always have questions about panel fitting for myself!

Flexible is in my view best, but sticking it to a curved roof creates issues of:
1. The curve tilts part of the panel away from the sun which can drop efficiency of the whole panel.
2. Getting it off if it needs replacing
3. Cooling.

So I would tend to go with roof gutter clamps and a panel long enough to bolt straight to the clamps. Then I'd add a curved piece of metal to the leading edge, and a folded bit to the trailing edge to reduce noise, flutter and drag.

As it is however, I have a portable flexible panel for manual deployment. However this '80W' panel only delivered 35W in full sun so it's a bit rubbish LOL.

Yes as with all solar panels the actual output never lives up to anywhere near the manufacturers claimed output so if need be double the size you think you need.

I'd take the totally opposite approach, something like a 20W panel, it will keep your battery in good condition and charged but not do the bulk of the charging. I'm lucky if I get way in the camper much more than once a month due to family commitments so I've 30 days to charge 80HA should be plenty. Saying that I'm still looking for a cheap one and I'm going to get rust fixed and a spraying done first. The joys of a 91 camper. Still love that machine if I had to choose between the wife and it, well you know they are a great van and hard to comeby

I've gone for a 130w flexi, as its the largest I could physically accommodate between the central and rear sunroof.

Hoping I can get away with white gorilla tape along the edges only rather than glueing the entire area.

Intend to experiment with cable routing upon its arrival as I am very reluctant to start drilling the roof.

I'll let you know how this turns out.

I'm interested as I'm wanting to set up a solar panel and batteries on mine as well (and also dont love the idea of roof drilling) Keep us posted.