Sunday, January 19, 2020

Solar enhancements

As this is a three day weekend I spent the first day hunting for a ladder that should have been around but wasn't. Perhaps it was pinched? Given the fact somebody stole the outgoing mail just before Christmas and there have been people cruising past at about 5mph clearly looking for bad things to do, it would not greatly surprise me.


In the end I decided that since I needed a ladder to get onto the hood of the bus to measure my solar panel precisely. I'd already ordered a pair of 20W panels to replace the vandalised 15W panel, but had based my measurements on what I could see of the tape measure held up from the ground. Those panels arrived a few days ago. Also arriving yesterday was the 60W flexible solar panel from China.

The solar panel from China was allegedly 60W but looked exactly down to the cell count like the 30W panels the Chinese are also selling. I had my doubts. It arrived in a very battered box.
With the way that box was bent and the way it was open, at first I thought whatever in must be surely broken. Then after realising it was a flexible solar panel, I was utterly amazed to find it intact inside the box. Whatever else was missing, I don't know.
Sadly there is no information on the underside of the panel to tell me what wattage it is. Given though that it has 36 segments like my 30W panels I doubt very much that it is any higher than 30W. Indeed, putting it on my solar system which has an almost depleted battery I got almost 10W out of it, angling it right at the sun, according to my watt meter.
There's the front of the panel. Notice that the wire connector is a humongous bulge on the back. That really and truly destroys any idea of mounting the thing flat on the roof of the bus. Honestly I'm not that impressed by this thing. The only thing this panel has going for it is that it is very lightweight and easy to put in the windscreen. 
Needless to say the panel came with the usual bizarre assortment of connectors. Nobody but nobody uses cigarette lighter plugs and sockets (well, I do and I'm slowly eliminating them). The first order of the day was to put an SAE connector on the panel so it will mesh nicely into my solar system since I have standardized on SAE connectors. I did try the funky connectors that came on my 30W panels but they were so hard to work with that I just cut them off and installed SAE. The 20W panels came with no cables which is my preferred route. That leaves me free to put the cable and connector of my choice.
I did get onto the hood today and measured the solar panel space accurately. It seems that my measurements of the other day were a little off. Putting the two 20W panels up there would be so tight on space that it's debatable as to how practical it would be.  Measuring carefully, though it would probably be possible to install three 10A solar panels, it makes more sense just to install two. That's still an increase of 5W over the existing 15W panel.
Looking carefully at the hood I can see the footprints left by both the copper that investigated the vandal that came around. Oh boy, was that an affair. I've probably not said what happened there...

There's vacant trailer on the property and it was being renovated in order to make it habitable. The painter brought (during school hours) her school-age son along. His footprints were everywhere. All around the bus, on the hood, inside the house, on the hood etc. The steps to get onto the hood had been flipped down, the battery door latch had been pulled so hard that it had jammed, but entry had been foiled by my lock. It looks like my locks kept the villain out. The solar panel had damage that was not present last time I'd looked which had been the previous day. The bezel was cracked as though somebody had tried to pull it off or had been on the roof. When confronted, it was total denial. Indeed it was hard to get any truth out of the painter. She told the people that hired her that she lived in Sumpter but turned out to live in Lexington. Just about every question asked came back with a provable lie. The people that hired her will not be hiring her ever again. As for the paint job - I hope she didn't cost much!
There's another view of the footprints on the hood. It can be hard to see them but they're still there a month after the vandal was on the hood. He must have been dancing on the hood or something. It was just unfortunate that my dashcam wasn't running at the time. It has been running 24x7 ever since.
As I mentioned I needed a ladder to get onto the hood. I'm not a sprightly young chicken any more. I'm older, fatter and not that flexible. Thus as ladders cost about $100 each and I already had several pieces of unused 2x4, I spent $25 on some 3/16th 4 inch screws and built a ladder. That took a couple of hours but an 8 foot ladder is a very handy thing to have. 
I've used that ladder a lot today and it's both comfortable, stable and safe even though carrying it, it's a bit heavy. I shall be using that ladder a lot. Bonus - nobody is likely to want to walk off with a home-brew ladder because they can't sell it. Nobody is going to fund their meth habit
Wiring up the new solar panel (the flexible one) I found one of my brand new SAE connectors didn't work. It conducted no electricity. Of course I found that out after I'd assembled everything. Fortunately I'd already tested all the other components so the diagnosis of the likely problem was pretty easy. Snipping it out of the circuit and testing it with my meter proved that indeed there was no connection on the negative side. Needless to say I reminded myself that skin and soldering irons don't go too well together when I was maneuvering wire ready to solder. I've done that plenty of times!
I've been having a problem with low power in the batteries. Today being the first really sunny day I plugged in my two external 30W panels and placed them directly in the sun. The battery voltage began to shoot up. While I was at it, I looked at my rear solar panels and saw they were filthy.
You really can see the dirt on those. No wonder I wasn't getting too much power out of them. As for the front panel, replacing it will give me more power. I'm also wondering how much power I'm getting out of it anyway since the vandal tried to pull it off. Mind, I was never very impressed by the fact it was held on by just four screws or by the fact the casing was plastic. It looked good which is the only reason I bought that particular solar panel. I liked the black of an amorphous panel as it looked to me more like a destination sign. The new panels will be identical to the rear panels. I bought two 10W panels via eBay rather than from Walmart because Walmart raised its price by $6 overnight. I might order another at some point.

The plan is to put the two new panels onto my aluminium angle bracket and hold it up in place. If I think I can get away with a third panel I can then order a third panel and have 50W total of built-in solar capacity. If not then I'll stick with two and 40W. My existing dashcam and door lock seem to have overpowered the existing 35W of built-in solar power due to the overcast skies over the last few weeks.
There, you can see clearly the much that came off the solar panels. That was a white kitchen towel. Awesome was sprayed on the panel and wiped off together with the dirt.

In order to get the batteries back up to power I've had the two portable 30W panels stood in the sunshine. That should work a treat fairly quickly. On the way I have an MPPT charge controller to replace my existing PWM controller. The only thing that really persuaded me to buy MPPT was that I read about it boosting a low solar input to a usable level. That would be great since incoming solar power has been really low.

As far as the flexible panel goes, I can definitely see a use for that. Nice and light, easy to hang in the bus windscreen and easy to store. I'd looked at putting the epoxy panels in the windscreen before as they're really light and easy to store.

While I was on the bus hood I looked at the roof. The vent is showing signs of rust so it's a very good thing I bought a replacement vent. I'll have to install that on a dry day. The elastometric roof paint is crumbling and peeling in places. I can see I'll have to wash the whole roof and go up and put more paint on the roof. That's no problem. Actually, it might be worth building some scaffolding from 2x4 and using my ladder to access it. Realistically it probably wouldn't take more than $30 of wood and maybe $30 of screws.

As for fixing the welding on the back door, I'll do that when I get myself a wire welder. That'll have to wait a couple of weeks though as I have a dental appointment coming up that's not going to be cheap and my government dental insurance only covers 10%.
There're my two 30W solar panels busily making electricity for me. The battery has gone from 12.2v to 12.8v. That's pretty much 70% of where it should be - at the time of blogging. Of course when I get the two new 20W panels connected that'll give me a total of 100W of portable power and my onboard 40W for a total of 140W. I'm not counting the "60W" flexible panel yet nor my 5W epoxy panel as the 5W panel is just used for testing things and I'm not sure just yet quite how much power that flexible panel actually produces.

In a few days when my MPPT controller arrives and when that has been installed I should get both better performance from my panels as well as more information about what's going on. My current PWM controller does just fine but wastes power when there's plenty sunshine and doesn't make much use of power when there's little sunshine. I'm hoping that it's going to act differently compared to my PWM controller when it comes to running the fans. Maybe it'll take power from the panels and supplement from the batteries. If it'll do that then there's no need for a flexible panel on the roof. Actually I bet that if there had been roof mounted panels, that little vandal would have been up there to dance on them.

One of the expenses coming up sometime will be tyres. The tyres on the bus are goodness knows how old. I know I've had them there since 2014 and that'll be 6 years in November. They were not new when I had them either and what's worse - the back ones are remolds (and the wrong size). That'll set me back a pretty penny! I'm estimating probably $1,500 though it could be more depending on who does them and what brand I get.

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