What Preps are you doing this week? Part 10

[deckard]

Nice, what sort of difference in Wh have you noticed since switching the controller?

I almost went with a controller called rover when I bought the renogy one I have now, not sure if it was the same back then. Wonder if my Bluetooth controller would work on that too. It looks a lot like the Epever tracer.

Btw, looks like you have the same breakers I have\had - beware I've some that fizzle and sort of half break well before their breaking current, and some that never break at all. One 80a one let me pull 140a through for 4 minutes without interruption. I'm binning the ones I have left asap

[Yorkshire Andy]

Nice, what sort of difference in Wh have you noticed since switching the controller?

I almost went with a controller called rover when I bought the renogy one I have now, not sure if it was the same back then. Wonder if my Bluetooth controller would work on that too. It looks a lot like the Epever tracer.

Btw, looks like you have the same breakers I have\had - beware I've some that fizzle and sort of half break well before their breaking current, and some that never break at all. One 80a one let me pull 140a through for 4 minutes without interruption. I'm binning the ones I have left asap

I'll be honest I've not had the meter on it since I upgraded sort of had to do the jump in one big hit.. leisure battery died ... Decided on lithium iron phosphate so needed a controller compatible battery all in almost one go and whilst I was at it I banged another panel up since I was relocating the other on to the roof one big hit but since spring I've not needed to do anything to it

Screenshot from the Bluetooth connection

I'm not even close to kicking the backside out of it

There is a irregular bit of data between consumption and generation the inverter is direct to the battery so it doesn't measure consumption from that

I've plans to shift it about in the shed to make it more Accessible to connect to the inverter and use it more .....


Thanks for the warning on the breakers might just swap them for old school fuses

[deckard]

Looks good. Yes I think fuses are just simpler and more reliable, I'll probably just use some maxi or mega fuses. Switched the one between my battery switch and the inverter for a DC MCB, purely because I already had the enclosure, but it takes up a fair bit of space. I've another inverter to wire in properly so may alter that too.

[jennyjj01]

I've heard the mppt controllers aren't really worth it until you start using higher voltages on the PV side or go over 200w, but it depends on cost really. Epever ones are supposed to be good and cheap, so maybe worth a spin but I'm primarily thinking a bit more on the panel side for when it's overcast first.

Have you experience of upgrading from pwm to mppt?

It'd also be nice to have better batteries as the ones I've got are mismatched; a 110ah leisure battery and an 85ah car battery, I keep them isolated from one another at all times except when I'm boiling the kettle, then I combine in the car battery to ease the draw on the main battery. A couple of proper deep cycle or traction batteries would be good, but expensive too.

Everything about solar is getting expensive. You need to think what your objective is.
MPPT or extra panels or anything else, only really costs in if you are utilising the energy that is delivered to your panels. E.g. if your batteries are fully charged and idle, then any controller will effectively just disconnect. In an ideal world, your batteries should just be smoothing out the bumps while the sun is powering something useful such as a fridge. But you don't want to be deep draining your batteries, nor ever really filling them: I'e.Load management is key to getting value. In my case, I use my four panels and 3 batteries to run a fridge freezer in the day, but switch it to run on domestic mains at dusk ( By a mix of time switches, controller features and relays.... and a modified car battery charger )
Of course the resilience from a system has its own value too, if it means you are more ready for a blackout.
I moved from pwm to EPEVER MPPT when I got to my third 100+W panel. Along the way, I optimised the tilt and position of my panels, Just doing the latter increased yield by about the equiv of an added panel. My fourth panel came with it's own MPPT, so I have a 2 controller bodge up of a system. MPPT blows PWM out of the water for efficiency even on a 12V system.
I suggest that as part of your load planning, you get these two items... You can then find the sweet spot in your power usage. I Estimated that the way I run mine, I'd save about £50 per year on electricity while my system cost maybe ten times that.
Bluetooth battery monitor https://www.amazon.co.uk/Battery-Monito ... hdGY&psc=1
Mains Power meter https://www.amazon.co.uk/Monitor-Backli ... 9hdGY&th=1

Consider trying to get a grid synched micro inverter. With that, you would get max energy cost saving, but would sacrifice resiliance of a battery system.

[deckard]

That sounds very cool, how does your cutover work @jennyj01 ? I've seen the opposite done, like a ups where the inverter kicks in when mains goes away. I guess you have to switch back when your DC voltage hits a threshold, is there a bit of kit for that?

The shed is completely off grid, and the solar stuff was just meant to be a standby thing for charging etc really. The sheds primary use is to store garden stuff, kids toys etc. A bit of a different use case I guess. I could probably move some computer kit out there to save money on electric, but it's a metal shed, I'd need to get networking out there and it gets very warm in summer; now I recall one of my reasons for adding another panel is it shades the shed roof.

I've got all the metering you mentioned, and the controller data goes into homeassistant;

I don't do any automations off the data yet, but i may do one day.

[jennyjj01]

That sounds very cool, how does your cutover work @jennyj01 ? I've seen the opposite done, like a ups where the inverter kicks in when mains goes away. I guess you have to switch back when your DC voltage hits a threshold, is there a bit of kit for that?
don't do any automations off the data yet, but i may do one day.

I will Message you, rather than hijack this thread, beyond the quick answer.
Using the MPPT controller's 'load' connected to a changeover relay: The MPPT controller has a 'dawn detection feature that turns on the load relay from dawn till dusk. So, dawn till dusk, the socket feeding the freezer is connected to domestic mains and during daylight, the relay is off and the load is switched to my inverter. A second small reed relay also on the 'load' actually turns my inverter off at night to save on it's idle energy loss of about 20W.
There is a secondary charge circuit which is a regular car battery charger feeding through a voltage limiter so that any time the batteries are below 13.5 volts, they get a little trickle. The more discharged they are, the more trickle charge they get and when they reach 13.5V the trickle charger draws no mains.
End result is that whenever there is sunlight, it's powering my fridge freezer, and batteries never get max charged, but at night, the batteries take just enough energy from the mains to get them to 13.5 volts ready for the morning. It needs a bit of tweaking for dark winter months, but generally pretty much all the energy delivered to my panels is used to reduce my electricity bill, while battery wear and tear is limited to a 12V-14V discharge range.

Health and Safety guys would flip out if they inspected the lash up.

[Yorkshire Andy]

Well I've had a stock taking day aka I've cleaned the shed..... Well let's say I'm fine for gas be it cartridges for tye heater and bistro stoves or big bottles got a rather big selection .. 3.9 propane 4.5 butane 2x 907 camping Gaz 7kg butane 6kg propane all full plus a 12kg butane in the old calor heater 5kg patio gas and my 2x refillable bottles ... Unleaded I've got about 20l plus 15l in the generator... currently charging the battery powered none solar outdoor lights .. the nights are slowly drawing in so I'll keep on top of that ..

About 5l of lamp oil and 10 of raw paraffin plus 3l of white Coleman fuel I've a blooming tinder box at the end of the garden not counting paints )white spirits rattle cans and DIY fluids checked all the fire extinguishers in there whilst I was at it

I've started on the one pack of batteries every time I visit b&m need to top up on d cells for the lanterns got about 6 lanterns that take 3x d cells each but they have a long burn time ..

[Arzosah]

Got going with the curtains that'll start the lightproofing in the kitchen - I'd abandoned them for 6 weeks or so.

Plus an hour a day for the last two days, in the garden - the wildlife has had a great summer - but the bit nearer the house really needs to get sorted a bit. I'm really feeling the urge to get the decks cleared.

[Nurseandy]

Spent most of today with a chainsaw in the woods . Also dropped off some diesel to a neighbour (we've changed cars to petrol so jerry can of diesel is surplus to requirements), got a bucket of tomatoes in return seems a fair swap

[Yorkshire Andy]

Spent most of today with a chainsaw in the woods . Also dropped off some diesel to a neighbour (we've changed cars to petrol so jerry can of diesel is surplus to requirements), got a bucket of tomatoes in return seems a fair swap

might try that at the local Esso garage need some more diesel as I serviced my diesel heater today and brimmed it ready for winter I've a farmer who's offer to fill my jerry can with red or kerro will soon be accepted I'll favour the kerro as I can use it in the oil lamps if pushed and it burns hotter and cleaner

I've also touched base with a ex colleague who lives in the sticks who has a big calor tank for his house with a liquid take off pump for his plant machinery he's said I can come help myself he pays 50p per litre for gas I'll happily pay in cash or alcohol