diy solar

diy solar

Hello from sunny England

AlfonsoX

New Member
Joined
Mar 10, 2022
Messages
8
Hello everyone,

I've been lurking around for a while whilst planning/thinking about getting a solar system for my house. It's always been a "huh, that'd be pretty cool" but now my electricity is going up to 37p (48 US cents) per kWh in about a month from 18p so it's now more of a "probably should look into that a bit more!"

I'd like to do as much of it as I legally can myself, to save money sure, but also because it looks interesting and I like DIY. I'm leaning more towards the MPPsolar all in ones and a DIY LiFePo4 pack but I'll have a search and read opinions and go from there really. Not really looking to supply the grid, that looks like it'll add quite alot to the costs and in England I'd only get 2-5.6p per kWh I export, unless there's something I'm missing - as I say "I probably should look into that a bit more"

See you in the forums ?
 
Solar power is very rarely cost effective. In the sunniest places on the planet with discount/used equipment is pretty doable.

I would see if you can come across big panels in the $.50 per watt or less range. If you cannot manage this, then your chances fall towards very little chance of ever breaking even.

If you have things like emergency backup needs that have a high value to you, it becomes more of a safety/luxury item than money saving venture.

The cost of learning something valuable and interesting adds value too.

I will stop trying to discourage you now, sorry.
 
Thanks for the reply, I don't have any emergency needs (although I do have a 4kWh UPS for some stuff because work was throwing out plenty of perfectly fine lead acid batteries) so my main goal was money saving, but with energy security and the satisfaction of making my own electricity being a part of it as well.

I've found some 395w panels for £162 each (I can fit 14 on my roof I think) so that'd come to £410/$537 per kwh. An 11kW MPP AIO is £1295/$1696. I've found some branded cells for sale in the UK (either EVE or CATL, can't remember now) for £178/$233 per kwh if you get 16 of the 280Ah cells.
That would come to £5915/$7748 for a 5.5kW array, an 11kW inverter/charger and 14kWh of lithium. From what I've read online where I live you can expect a year average of 3x the array maximum output per day so 15kWh per day average. In summer some of that would go to waste though. My last electricity bill said I use 8kWh per day, so I'm hoping that for a lot of the year I could eliminate my electricity bill, and in the summer also eliminate my gas bill for hot water by using the immersion heater.
My yearly electric bill will be around £1080 so I figured £5915 for the set up isn't too bad.

Now I know I've left lots out of my calculation (BMS/Wire/Fuses/Panel mounts) and in the winter the standby losses of the inverter would be a significant part of my solar generation, but I figured a payback period of circa 10 years is fair? (feel free to laugh if I've missed something major or pressed the wrong buttons on my calculator) Before I buy anything I'll do more than napkin maths though! Then there's the "does it add value to the house when I come to sell it" aspect as well which is a complete unknown!
 
but I figured a payback period of circa 10 years is fair?
I didn't check your math but sounds about right and a reasonable goal. This all assumes your equipment lasts the full 10yr term which i have found to be the biggest factor in ever reaching break even. Quality equipment, which is more expensive up front helps on this but can push the break even point further out. Clearly a risk/reward scenario!

I tend to strongly prefer products, particularly charge controllers and inverters with a couple years of warranty.

I will have to say though, the journey is quite fun and horrifically addicting. I apologize to your wallet up front for now becoming somewhat encouraging...
 
Hello everyone,

I've been lurking around for a while whilst planning/thinking about getting a solar system for my house. It's always been a "huh, that'd be pretty cool" but now my electricity is going up to 37p (48 US cents) per kWh in about a month from 18p so it's now more of a "probably should look into that a bit more!"

I'd like to do as much of it as I legally can myself, to save money sure, but also because it looks interesting and I like DIY. I'm leaning more towards the MPPsolar all in ones and a DIY LiFePo4 pack but I'll have a search and read opinions and go from there really. Not really looking to supply the grid, that looks like it'll add quite alot to the costs and in England I'd only get 2-5.6p per kWh I export, unless there's something I'm missing - as I say "I probably should look into that a bit more"

See you in the forums ?
Your electricity is doubling? How can they do that? We'd have rioting in the streets!
 
Your electricity is doubling? How can they do that? We'd have rioting in the streets!
My gas has also gone up from 2.9p/kWh to 10.3p/kWh. The government sets a price cap that suppliers can charge customers for gas or electricity, but that's based on wholesale fuel prices to stop them making excessive profit. Wholesale prices have shot up, so prices customers can be charged has also shot up.
The UK is shutting down lots of it's nuclear stations in the coming years and we're only building 1 to replace them. Coal fired power stations are almost fully banned. I can't see electricity prices coming down any time soon here.
 
I will have to say though, the journey is quite fun and horrifically addicting. I apologize to your wallet up front for now becoming somewhat encouraging...

I'm already finding it interesting and I haven't even got a solar setup yet :)
And yes, I'm sure my wallet isn't going to find it as fun as me!
 
I'm already finding it interesting and I haven't even got a solar setup yet :)
And yes, I'm sure my wallet isn't going to find it as fun as me!
Hi fellow Englander,

How are you getting on with your Solar journey, I am in a similar boat as yourself and still trying to get my head around what I want/need.

Have you pulled the trigger yet on any of the components?
 
How are you getting on with your Solar journey, I am in a similar boat as yourself and still trying to get my head around what I want/need.
Start a new thread with as much info about your energy usage and overall goals so we can get to work on this!
 
Have you pulled the trigger yet on any of the components?

Nothing expensive yet, still working out the best way to do things. I'm thinking have a IEC-60309 230V 63A wall mounted socket and plug installed in my roof fed from 16mm2 cable and a new consumer unit with a changeover switch.
I could then get an economy 7 tariff (or a similar smart meter one, I think octopus energy do one with free electricity for 2 hours a day) and configure the MPP 11kW AIO to charge to a certain battery percentage in winter on cheap rate if I'm unlikely to fulfill all my needs from the solar panels.

I ordered some of the solar mounting brackets from bimblesolar.com, they seem to be the cheapest I can find and are still a decent quality. Definitely a website I'd recommend checking out.

Batteries are an issue. It seems the term "Grade A" is useless and both genuine sellers and scammers use it. Might just pay a premium and get some from a UK seller.
 
Hello everyone,

I've been lurking around for a while whilst planning/thinking about getting a solar system for my house. It's always been a "huh, that'd be pretty cool" but now my electricity is going up to 37p (48 US cents) per kWh in about a month from 18p so it's now more of a "probably should look into that a bit more!"

I'd like to do as much of it as I legally can myself, to save money sure, but also because it looks interesting and I like DIY. I'm leaning more towards the MPPsolar all in ones and a DIY LiFePo4 pack but I'll have a search and read opinions and go from there really. Not really looking to supply the grid, that looks like it'll add quite alot to the costs and in England I'd only get 2-5.6p per kWh I export, unless there's something I'm missing - as I say "I probably should look into that a bit more"

See you in the forums ?
Welcome,

I have just had a 9.9kW system installed with an 8.3Kw inverter, but I’m in sunny (supposed to be) Australia. Back visiting the UK in August.

First thing to consider is when you actually use the majority of your electricity because if you can use most of your electricity in daylight hours then you will greatly reduce your costs and then you really need to consider whether it is effective for you to install batteries. 8kW a day is very little 365 x 0.37 = £1080 annually. Electricity companies here also impose a daily supply charge, which I have no doubt that they do there also, so don’t underestimate the 5.6 p export as say 7kW per day back to the grid 7kW x 5.6p x 365 = £143.08.

If you calculate that you are for example using 3kW from the grid a day that is 3kW x 0.37p x 365 = £405.15 annually so you will need to consider that against the cost of batteries. It would be interesting to see your final figures.

In my case batteries are not cost effective for me as in February my electricity from the grid cost me AU$5.54 and in March so far even with all the rain AU$19.13 so $24.67 for 2 months electricity.
 
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Electricity companies here also impose a daily supply charge, which I have no doubt that they do there
I've got a daily standing charge of 42p, even if I use nothing. You can get tariffs for holiday houses with no daily standing charge but an elevated kWh charge. I'd have to work out how many kWh per day it would be cheaper to go for one of those.

8kW a day is very little
My house is fairly small (completely filling one side of my roof would only get me 5.5-6kW of panels) and my heating/hot water is via gas. I've only got air con in the bedroom for when I work night shifts during the summer and have to sleep during hot afternoons. Just checked this months usage and I'm at 8.5kWh per day.


Something I didn't think about is I've got 3x 1.5hp air compressors and a welder for tinkering on cars and hobby stuff. Not sure what the power factor is on those and how nicely they'd play with a high frequency inverter, if it's a big no-no I could switch back over to grid when I'm playing in the garage. The more I think about going solar the more roadblocks I seem to run in to. Still looks interesting though, I think it'd be rewarding to know that my electricity (or at least some of it) was generated by myself and I wouldn't mind paying a bit of a premium for that - just not too much of a premium!
 
I've got a daily standing charge of 42p, even if I use nothing. You can get tariffs for holiday houses with no daily standing charge but an elevated kWh charge. I'd have to work out how many kWh per day it would be cheaper to go for one of those.
So on a rough calculation your feedback to the grid would almost cover the daily standing charge. Therefore you only have to consider the amount of electricity you will consume from the grid and whether it is cost effective as opposed to the cost of buying batteries.

In my case it clearly isn’t.
 
Just seen this... If it's any help, I am totally off grid and run a 3hp air compressor off a 5kw inverter no problem. It gets messy when the plasma cutter is added into the mix and then I need to run the generator lol. I also have a 200 amp inverter mig which only uses about 800 watts running at half power (100 amp ish) Over a prolonged period, as long as the panels are bringing in enough, they will run all day. I only have 4.2kw of panels but am in southern Spain. The compressor tends to overheat before the power runs out ?
 
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