MadModder

Huge variation  in prices Steve, I used Renogy 100W panels, in my case they are a manageable size costing about £69.00 per panel.   However I could have bought 440W Jinko panels for £68.00 so about £0.155 per watt.  For me the panels are too large and heavy to handle on my own, but that cost per watt !!!  They also wouldn't have provided the higher voltage I wanted as my Renogy panels are 4 in series then parallel with the other 4, making best use of my charge controller or in this case the Bluetti built in one.

Ade, rain dropped temperature here and sun just came out, our 800W array just peaked at 850W, so I was 100W down during heatwave.

Bill, interesting take on your view, I never saw this as an investment but something that interests me.   As Steve Jobs book title "The journey is the reward"  It also helps I have great support from my wife, who was in engineering.

What are panels going for these days per watt?

Ade, hang on till after the winter storms before deciding on a tracker, see how mine copes.

  

Eco Worthy US have a larger tracker option, anyone’s guess if it will make it to UK store.   You also need to provide a 12V supply at the tracker, could be a battery but would likely need another small panel to keep it charged.   Plenty of YouTube vids on these trackers.

Fortunately, I already have a 12V panel  It's nigh on 20 years old, but has spent most of its time in the box indoors, waiting for me to play with it....

Hoping to move to a new house late this year/next year - I'd like to coat the roof with solar, have some big ass batteries to store the power, and maybe a tracker or two depending on funds/motivation/etc. If I can grab enough energy to keep my car charged up over the summer, and to help a bit in the winter, I'll be well happy.

Ade, I can tell you at the height of the heatwave the array was most likely only 50W down on its max capacity, won't know till a bright sunny cold day for sure.  I use a thermal camera to survey the panels during the day, it is also used on all wiring and equipment to watch for issues.  Picture attached was the hottest day we had and actually had a fuse holder melt on the workshop rack for another device.

We still generate power on overcast days, might only be 10% of the arrays power, but every little helps keep grid charging at bay.   We bank power using the storage and try to use what we have if we know we can get more over the next few days.  Can be a tricky balancing act but we gradually got a system that works during the winter.  Quite often after snow and you get a sunny day, clean the panels as quick as possible as reflected light gets bounced back strongly by a bit of cloud or even the snow itself.  It probably helps that it's just the Mrs, me and the dog and we don't own a TV, so no constant drain on our system.  We use RV fridge and freezer, that help rotate food more quickly, but also means we can move them into the conservatory where it's cold in the winter so their energy demand goes way down.   No worries in summer as we usually have way more power than they need, but we move them into the kitchen where it's shaded.

Just looking at Eco Worthy's website again.... Their solar tracker thingybob + 6x 195W panels is coming in at a hair under 72p/watt capacity! That's bonkers! The last (and, indeed, the first...) solar panel I bought was nearly £1 a watt just for the panel alone, without any other gubbins to go with it, although that was a few years ago now. In fact, a single 195w bifacial panel is rather cheaper than the 100W monofacial panel I bought back then. Honestly, it feels like I've blinked, and the bottom's fallen out of the market!

Definitely going to be looking at one (or more, depending on garden size!) of these next year.


 

Speaking of heatwaves.... (we're not having one oop north right now!  ); I believe solar panels lose efficiency when they get hot, which is always a pain as the best sunshine usually comes with a lot of heat too...

So then I got to thinking - which is always dangerous  - in Ye Olde Days (1970s and earlier) one could have "solar panels" on the roof, but they were thermal panels, not PV. i.e. they warmed your water up... My grandparents had one on their roof for donkeys years... although unfortunately they died & the house was sold long before I got interested in this stuff.

However - I got to wondering: How hard would it be (famous last words!) to create a hybrid PV/hot water panel? i.e. make a normal thermal panel (lots of black-painted copper pipe in a think black box); but instead of putting a glass front on it; put a solar panel on it instead! Now... obviously the panel's going to eat a lot of the potential heat; but since it's going to get hot, wouldn't the thermal panel underneath suck out a lot of that heat? Which could then be used to pre-warm a tank of water - and, given that heating water is one of the most energy intense things we modern people do, wouldn't this save some energy (In summer at least!) by a) using the heat energy, and b) making the panels even more efficient than they already are?

Sadly, winter is going to be its usual problematic self, with bugger all sunshine at low angles & low temperatures limiting any available heat (and one might need to deal with freezing temperatures too)... but I do wonder if, for those hot summer days, it might be an interesting system at least?