Muhendis

End of play today and all the new panels are all in place. Each panel is 550 Watt and seriously big and heavy. Size is 2.2 metres by 1.1 metres and, coming in at 35kg, highly recommended for industrial use. The silicon is 'N' type and half cell size. The flat roof is over 3 metres up so we (myself, wife, a nephew and a niece) did some interesting and innovative things with a ladder and some rope. I noticed that the frame of the panels is a bit floppy so I will be adding a bit more supporting truss work tomorrow. They don't make 'em like they used to.

A couple of days ago I removed all the old panels from my carport roof and started assembling the steel supports for the new panels.

I mentioned I would be replacing my 11 year old solar panels earlier. Why do I want to do that? The older panels are well worn out in the sun all day and the output is down enough for me to do something about it. Panels, particularly older tech ones will suffer from micro cracks, reduced intercell conduction, complete shattering of the front glass and UV light protection failure. Mine also suffered from being rated incorrectly with the sales pitch quoting them as 200W each but the label on the back making them to be 178W each. The micro cracks are in the silicon and will make it a bit tricky for electrons to travel from one side to the other. The burnt parts of the rear plastic layer in picture 2 are caused by the aluminium interconnections going resistive. The shattered glass in picture 3 is the result of the heat generated by the aluminium interconnections. Picture 4 shows the brown patches caused by failure of the UV protection layer.

Yeah. I had some similar excitement with my battery delivery. They were all on a single pallet and came in at a whopping 940 kg. I used a local courier from Bangkok to Buriram where I knew they had a forkin' lift. They fitted in the back of my Izusu 4x4 very well when I went and collected them. Downside is It cost 1k Baht to get them to the Bangkok depot from the Bangkok port warehouse.

I'm going to backtrack on this a bit. The plywood is still a reasonable idea but, having gained some more knowledge I would supplement that with aluminium foil arranged to have free air on both sides. I changed my idea because I read this:- https://radiantbarrier.com/blogs/news/how-radiant-barrier-works-heat-gain-loss-in-buildings#:~:text=Most aluminum insulation has only,strikes its air-bound surfaces.

That's the sort of thing although it looks a bit thick and heavy. Thaiwatsadu also have some 5mm thick plywood which might be better

What I would do would be to screw some thin plywood or cement board to the underside of those, what look like, 30mm x 30mm steel roof panel supports. This would create an air gap which would reduce heat significantly. If you could also fill that air gap with fibreglass insulation, that would be even better.

Yeah! Go for it man. We're all behind you.

I should think you'd need some of your neighbours roof for that lot too. Are you thinking of selling power by any chance? 🙂

Don't forget to factor in the temperature coefficient. It's -3.5mV/cell/°C from 25ºC. Also note that is not an ambient temperature but rather the temperature of the cell. Each cell produces nominally 0.58V off load at 25ºC so for example, at 35ºC the cell voltage would be 0.58V - (0.0035 x 10) = 0.545V. The caveat is the assumption that you are using P type panels. If you were to use N type panels the losses would be -3mV/cell/ºC.

I've often wondered that too. In the Uk, police officers have a warrant card which, I believe, gives them powers of arrest if they suspect a crime is being committed. In Thailand police seem to need a court order first.

I'll drink to that. Pool table too?

He didn't answer because he probably didn't know. The drop is currently 1% in the first year and 0.5% (or thereabouts per annum thereafter). However that's with the most up-to-date technology. Older technologies generally offer 1% - 3% per year. https://chintglobal.com/blog/n-type-vs-p-type-solar-panels/#:~:text=What is the primary difference,expensive than P-Type panels. This is a difference in efficiency. The best is N type which also has a voltage drop per cell of -3mV/ºC whereas P type is 3.5mV/ºC. This may not seem like a lot but when you calculate the open circuit voltage of a panel at a particular temperature, it can make a significant difference to the maximum input voltage rating of the inverter. Now. This is all very well but over the horizon gallops the PERC panel. This fellow has the ability to add some reverse reflected light to the panes output which increases the efficiency yet further to as much as 24%. But hold your horses there. You can only get the best out of these guys if they are at an angle to the backplane. Mounted on a roof they are not going to achieve the benefits of reflected light. DIY is the way to go. But do some research first.

Is a Russian in Phuket because he wants out from Putin's lying tyranny and he has no desire to kill his neighbours in Ukraine.

This reminds me of the cadmium scare in Chedar Somerset UK. Many years ago, cadmium was found naturally to be in the soil of peoples gardens. The folks had been eating it for years in their home grown vegetables.