Well, I've just finished putting 680 watts on top of my bimini
keeping the standard 1" bimini
tubing, but adding a couple of extra tubes to stiffen it a bit better.
I took a different approach. Glass panels weigh in the mid 40 lbs range and I could not put that much weight up there, so I put four SunPower E-flex 170 watt panels up. I only chose the flexile panels because each 170 watt panel weighs 6.25 Lbs. But... I did not want them to flex by putting them directly on the canvas
as so many have done. So I turned them into rigid panels by framing them in aluminum
square tubing with a flange all around and also using a backing to make them more stiff/rigid by inserting 6mm thick Lexan
"ThemoClear"in the frame with them. ThermoClear is paneling used in greenhouse construction.
I put two 170 watt panels in each frame so it looks like I have two rigid panels up there but it's actually four separate 170's. So each 340 watt combined rigid panel weighs about 24 Lbs, or about half what one glass 300+ watt panel would weigh. Then I added a couple of extra 1" tubing struts to stiffen the bimini "wobble". The entire thing is pretty rigid now.
Not quite finished wiring
it all up but should be finished tomorrow. I used 4 separate Victron 75/15 MPPT
"SmartSolar" controllers -- one for each panel (Bluetooth networked with my Victron BMV-712 Smart Monitor
Hope this help give some thought about getting more watts with less weight.