Solar electricity...........not for your house

Someone-Else · Post by **Someone-Else** » Fri Mar 17, 2023 12:18 pm

Just wondering.............
We all know that you can generate electricity from sunshine using photovoltaic (As opposed to thermal) solar panels, so for your house (In short) you get a company in, they put panels on your (west) facing roof, connect it to an inverter maybe a battery etc and away you go.

But I am wondering have any of you thought of (For example) putting "electric solar panels" in your garden/shed/outbuilding (what ever) to power.............(What ever you choose) if so, what? Not interested in what you can power, example: lights for shed, or train set etc. I am genuinely interested if anyone here has done it, or assisted with it. I have seen a bloke (on YT) who powers his PC, and a couple of lights.

dewaltdisney · Post by **dewaltdisney** » Fri Mar 17, 2023 12:36 pm

We use garden solar lights that have a small panel to charge the batteries. From this, I deduced you need a big area of photocells to get any decent electricity. I did not want them on my roof as they are ugly. I did look at getting some panels and doing a DIY job but lost interest as it was ( and probably still is ) an industry full of snake oil salesmen. My thoughts were to put them on the roof of our stables but then decided that they would be too vulnerable to theft (the price they are) As usual it was an idea that fell to the side of the pathway of my life. This is an interesting read https://www.********.co.uk/solar-ener ... nel-prices The forum is blanking this site, no doubt for good reason insert green match without the space

DWD

arco_iris · Post by **arco_iris** » Fri Mar 17, 2023 9:33 pm

I'm just in the process of setting up a system such as you describe, which is termed "off-grid". Panels should be south facing, S-E, not west (although west will work, to a lesser extent).

The project is only a couple of days old, as an afterthought by SWMBO, we are having a 13' x 10' stone building refurbished, former goat shed in a field adjacent to our holiday lets. No hope of getting 240 volts down there due to the distance and the original intention was to use it for winter storage of garden furniture, keep a lawnmower in it, and for those guests who request it, secure storage for their bikes & paddleboards, etc.

'Er Indoors, who runs the cottages, suddenly thought it would be a good idea to make a BBQ & seating area down there, with solar lights. Researching this a couple of days ago, as DWD says, there's a lot of snake oil, rip-off merchants and cheap Chinese gear on A-zon & fleabay.

The new roof is being slated next week, so I urgently needed to find mounting brackets.

After a few hours I found a website with an address locally that offered brackets online. So I emailed to ask if they could be collected. Turned out that the site is run by an elderly gent, over 40 years as an electrical engineer, as a hobby in his retirement, and very helpful he has been too in explaining all sorts of things.

I've got the brackets for the roofer now, but not picking up the panels until the end of the month.

Someone-Else · Post by **Someone-Else** » Sat Mar 18, 2023 1:39 pm

Thanks to both of you.
I know that a garden solar light is a complete waste of money, I have tried quite a few over the years, I have had them:
Leak/corrode
Fill completely with water (No drain hole, too late when I found out)
Solar panel changes colour to a "foggy white" so stopping it from generating electricity.
Solar panel itself leaks
Battery just fail
Solar panel too small, so even in summer light only lasts for 2 hours

I have tried.
Umpteen "light on a stick" solar lights (As you can guess, various shapes of plastic encasing a LED etc on a hollow "stick" of some description)
Solar panel and lights on a string Light (wires snapped)
Solar "road works" light (That was a joke as, although it had 3 Leds a torch with a normal (incandescent) lamp was brighter
Solar lighthouse, looked "nice" worked for 2 nights, then it gave up (The light really did rotate, when it worked)

(I even had a mains festive lantern string, that lasted a few years, but the coloured plastic cracked and broke after a few years)
I am more interested in a couple (Not loads) of big (Not huge, no real idea of size) of solar panels and required parts to see/find out/test if I can power something (Not found the exact something still looking, but I have an inspiration.)
Something vaguely along the lines of what arco_iris is looking to achieve, but I am wondering (since this is a DIY forum) if anyone else here has done or has similar?

If it helps, I did once get a 50Watt flexible solar panel to charge a battery, to charge a battery to run a LED light for the shed.
As it was flexible, I mounted it to a piece of timber. (The timber outlasted the panel, as the panel turned yellow) mounted the timber to a PVC down pipe (Cut the end of the pipe at roughly 40 degree angle, screwed the timber to the pipe) Mounted the pipe to the side of the shed, so panel was away from roof, but pointing towards sun. Connected panel to charge controller and small lead acid battery. Left it for over a year, battery would never last long (Put battery on dedicated charger, worked fine) so it was either the panel or charge controller (It should have lasted longer each night than the 10 or so minutes it did last)
As electricity prices are what they are (Does anyone remember what they were? we are about 40p/kwh really can't remember what it was.) I want to try again, but as I said at first, its NOT for the house, just a little something that is annoying me.

arco_iris · Post by **arco_iris** » Sat Mar 18, 2023 4:46 pm

The "inexpensive" garden decoration type use rechargeable AA batteries & will last a bit longer if they are replaced when spent, but basically they're rubbish.

I don't think you're going to like this, S-E..... I'm looking at:

6 x 170watt panels each approx. 1500mmH x 700mmW producing 1kW in winter, more in summer, £900;
4.2m width spanning seven rafters at 600 centres needs 14 roof brackets/slate flashings at £25 each (hope to use fewer), two mounting rails & associated clamps £200+, comes to around £550;
Controller between £300 - £600
100Ah leisure battery, £90 - £150, option to have two in parallel (200Ah) or series (24v)
this powers 12v (24v) to 220v inverter maybe £50 - £100;
feeds into "garage" type 2way RCD consumer unit £25;
associated conduit, wiring, metalclad sockets & light switches, etc. left over from previous projects, earth rod into the ground, free using a roadpin.

Indicative prices above include VAT (saving by using folding stuff & collecting, budgetting on £2k).

This SHOULD run, don't actually know, inside & outside lights on sensors, fridge/freezer, kettle, toaster, battery chargers for ride-on mower & cordless tools etc.

Don't ask any complicated questions!

aeromech3 · Post by **aeromech3** » Sun Mar 19, 2023 3:37 am

I have a couple of ex car batteries I keep topped up, they connect by clamp-wire-studs to a RS 300watt (600watt surge rated) pure sine wave inverter which cost about £120 two years ago, from that to a rotary cam switch (Heschen £13) which connects the boiler supply either from mains or inverter output with a neutral isolated position in between; it works fine for the heating system and gives about 90 minutes before the battery voltage drops to about 11v then the inverter alarm starts, followed by disconnect protection (annoying but essential).
I tried with my under counterl fridge, rated 110watts, but sometimes it would just cut when the compressor starts meaning 600watt surge was not enough.
So a_i looking at your list, the fridge/freezer might be a non starter (pun!) for a circa £50 to £100 inverter, but I also have a non compressor type work top fridge and that is okay. I have a second 150 watt pure sine wave which is enough for the vented Y plan heating system.

arco_iris · Post by **arco_iris** » Sun Mar 19, 2023 6:03 pm

aeromech3 wrote: ↑Sun Mar 19, 2023 3:37 am I tried with my under counterl fridge, rated 110watts, but sometimes it would just cut when the compressor starts meaning 600watt surge was not enough.
So a_i looking at your list, the fridge/freezer might be a non starter (pun!) for a circa £50 to £100 inverter

Thanks aeromech, spoke to my supplier about this today, to which he said for surge reckon on 3x power (330w) plus a bit. On that basis, 600w inverter ought to be enough..... but I did say earlier "maybe £100" - maybe a bit more!

I'm planning on hard-wiring the fridge - then if there is only one 3pin socket, e.g., kettle/toaster/microwave can only be used one at a time.

In his late 60s, I learnt today, he has been running the business for 26 years, starting as supply & install then as poor health caught up, moving to supply-only & online. He says he's so busy he can barely cope, he seems to know his stuff and is being extremely helpful, so far.

Someone-Else · Post by **Someone-Else** » Sun Mar 19, 2023 9:25 pm

I always knew it would never be cheap, decent solar panels never are, then you need (Usually) an inverter (Changes generated DC voltage from what ever it is to 240v Ac) and some form of energy storage (Battery)

If however it is just for a few lights, it is possible to use 12v lights, so doing away with the inverter, but a battery would still be required. (As well as solar panels and a charge controller)

I am still deciding, but will follow with interest.

Pictures would be good too guys.

arco_iris · Post by **arco_iris** » Sun Mar 19, 2023 9:58 pm

Someone-Else wrote: ↑Sun Mar 19, 2023 9:25 pm Pictures would be good too guys.

I don't have much to post yet.

: 20230214_122140.jpg (626.25 KiB) Viewed 1916 times

: PXL_20230314_150246448.jpg (271.71 KiB) Viewed 1916 times

: PXL_20230314_150313407.jpg (303.73 KiB) Viewed 1916 times

Someone-Else · Post by **Someone-Else** » Sun Mar 19, 2023 10:29 pm

aeromech3 · Post by **aeromech3** » Mon Mar 20, 2023 4:07 am

a_i , yes that is what I thought hence why I first bought the 300watt version, the fridge was new when I first tried perhaps it needed to run in! I tried with my older same size freezer, but that caused the inverter to cut more often, perhaps there is a voltage dip from my smaller batteries that does not help, whereas your leisure battery is likely to sustain the short peak amperage.
As the article and you have made me think a bit:-
I will give it another try when I return home later this week and perhaps have a multi meter connected into the battery too.
I might also connect a charger to the batteries ( as no power cut) as another exercise whilst trying the fridge.

arco_iris · Post by **arco_iris** » Mon Mar 20, 2023 3:22 pm

The mounting brackets are fairly substantial, but we don't want the prevailing sou'westerlly wind getting under the panels, causing them to lift. Bottom row fitted, another seven to do, higher up.

: 20230320_150731.jpg (389.43 KiB) Viewed 1893 times

: 20230320_150759.jpg (386.3 KiB) Viewed 1893 times

aeromech3 · Post by **aeromech3** » Wed Mar 29, 2023 2:54 pm

As promised: connected up one of my older 44Ah batteries, it managed a few fridge starts and then even with 10ampere back up from my charger it failed to start the fridge and now though the battery has about 11v, it won't take a charge or anything but a light load. So, my classic Beetle battery is 22yrs old and still starting the old girl, but it made me think it might also let me down, so bought a new one 47Ah for her and this is supporting the inverter fridge as I type and seems to cope, but for long I am not going to risk much below 12v.

nemie · Post by **nemie** » Sun Apr 09, 2023 4:15 pm

I started a self build few months ago due to possibility of power cuts and power cost, had it up and running by December 23rd 2022, and most days I was maxing out my input around 106v so don't need full sun for a system to max out, I set up as parallel so volts is my measurement, I bought 3x 420watt panels and 2 good batteries "12V 220AH LEOCH AGM LEAD CARBON DEEP CYCLE BATTERY".

I installed in the kitchen so can cook on an induction hob and boil water from low watt kettle, also can charge family devices plus have lighting system on standby ready for use if black out happen, also a small freezer.

I would list my whole system but you don't seem to want/need solar for emergency.

One thing I will add panel placement is individual to each build like I get morning sun from the east then late morning to afternoon sun from the south and last bit from the west, my house blocks north, so for me to max sun my curve is: east-south-west.

Just took this photo I am almost maxed out of full power my setup can bring in.

arco_iris · Post by **arco_iris** » Mon Apr 10, 2023 5:02 pm

Works are slow, bad weather last few weeks. Barn structure almost finished, hope to get PV panels up over Coronation weekend.

: 20230410_174222.jpg (610 KiB) Viewed 1813 times

View from north-west

: 20230410_174253.jpg (515.94 KiB) Viewed 1813 times

View from west

: 20230410_174320.jpg (546.22 KiB) Viewed 1813 times

View from south