@anthropy @maruno @TechConnectify My budget to install 8kWp on my roof in Belgium when I bought the panels in 2023: 4K€ panels, 2K€ supports, screws, cables etc. 1.5K€ inverter and at least 50 hours of my time (not finished yet). Today the panels part could be reduced to 2K, but the energy policy makes injected energy worthless, so I have to account for a battery for when my EV isn't charging.
Panels are cheap but we're often forgetting the other equipment and work needed to install them.

@aris @maruno @TechConnectify Batteries are also cheap if you know where to source them, same goes for the inverter; 1.5k sounds like a fancy one, I got two offgrid inverters each capable of 6kW+ for less than 500 a piece, and roughly 15-20kWh worth LiFePo4 cells for 800 ish, a BMS for 250.

I'm guessing my situation made them easier to install though, as I'm putting them down flat on my carport with clamps on the sides, my 5kWp took roughly
5-10 hours. It honestly depends on your situation.

@TechConnectify listening to the last five minutes of this video ️‍

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@anthropy @maruno @TechConnectify I wanted SMA (5kW dual input single phase) but it was a mistake. Where would you recommend buying batteries in Europe? The prices I found were around 300€/kWh so way more expensive than what you tell me, but I haven't done thorough research yet (I wanted to study my overnight power requirements first)

@aris @maruno @TechConnectify I actually source them straight from China, because they are the king of LiFePo4; in 2012 ish western manufacturers choose to go with nickel-cobalt chemistries, which are far more expensive, because at the time they had a much bigger capacity per weight. These days they're very similar.

To add, China tried to flood the western markets with cheap EVs but got held back by regulations/taxes so they have a huge oversupply of these batteries and sell them for dirt cheap

@aris @maruno @TechConnectify You do have to look around for reputable sellers, because of course the cheapest ones are also cheaply built, but there are very good ones that are also used in cars and such. I'm a bit busy / between things right now but if you look around a little you should be able to find very good *and* affordable ones

@anthropy @maruno @TechConnectify Since I would be buying separate batteries and BMS in that case, that requires research and knowing perfectly what I do. But the price difference seems worth it, I'll delay this until I have to to work on it.
Thanks for sharing your experience.

@aris @maruno @TechConnectify As long as you have a BMS that is appropriate for the load (overspecced but configurable is okay but make sure to configure it to turn off at the maximum load), it should be fine. It's also worth noting that if you have a low voltage pack (e.g 24V in my case) you have to get really thick cables to carry the amps (48V might be better in that sense).

I'll try see if I can find some good cell manufacturer examples later. For the BMS I personally use Daly.

@TechConnectify
Watch until the end!

@anthropy @maruno @TechConnectify Do you wire them between the panels and main inverter or on the AC side? I was careless when designing my setup 4 years ago and didn't think I would need batteries anytime soon, so the SMA isn't really designed for battery storage, I would have to build around it.

@anthropy @aris Do take into account your time and what you are getting into, that it's still not finished is an indicator how much worth it can be.

But also I quite frankly find it a bit dangerous what you are preaching to just get any random stuff from China without approvals. (I guess it wasn't apparent) Consider what risk you are taking and comfortable with.

@TechConnectify @GoodNewsGreyShoes Make sure to watch the entire thing.

@maruno @aris The LiFePo4 cells they're selling here for 300 are sourced from china for <100, they're the same cells, you just gotta know which ones to get.

My system is working, batteries and all, and sure I could and want to upgrade it further, but that doesn't mean it can't be something relatively easy to deploy.

@mattesilver @TechConnectify usually the warranty is that after 25 years the panels will still produce at least 80%, these days often even more, and that's the *minimum*, if one is lucky¹ it could easily be more.

¹ or lives in an area with cooler summers, and/or has bought more expensive panels with a better warranty

@anthropy @aris You know very well I am not talking about base materials such as the LiFePo4 here, which the average consumer shouldn't even know. But what it is put in, it's certification and the certification, safety and requirements of the full installation and what you are connecting it to.

You do you, but mains and high voltage DC electricity is not a toy.

@maruno @aris I don't like your condescending tone, and honestly don't care to fight about this right now as I have better things to do.

But I presume that someone knowledgeable enough to have been working on their own setup already, is capable of handling low voltage DC lithium batteries.

@valhalla @TechConnectify

thank you, I got it from the other answers.

Somehow no one mentions longevity of batteries...

Another thing is that it's all stupid-"smart". I have a PV installation, and it all requires connection to some 3rd party SaaS. Once the company goes belly-up, as they often do, it's all an expensive paperweight.

@anthropy @maruno I think the warning and words of caution are fair. These batteries can cause fire and if after inspection (if me and my family is still alive) the experts say my no-name hacked battery setups caused it, I may find myself homeless. That's why despite the margins I may end up buying from an European seller. I need to put more thoughts into it.

@mattesilver @TechConnectify batteries were mentioned in the video, in the context of how car batteries have been exceeding the longevity expectations by a lot

as for the smart, our installation is smarter than I'd like, requires a connection and sends data to a 3rd party, but when (not if) internet is not available it's still producing energy, storing it in the batteries and using it locally; I'm not sure about reselling it to the grid, but I think that would also be working. The part that will disappear if the company dies is just the data logging and reporting, and losing that would be bad, but not as bad as losing everything else.

@aris @maruno and that's entirely fair- I'm not saying not to be cautious, but I find it a little much to say that neither of us know anything about this and that I'm "preaching" for unsafe setups, when I've explicitly said I'd have to look into what good cells are later.

Any setup can cause a fire, and I've seen some extremely scary thin wiring and connections in premade bat boxes that are "okay because we probably don't pull that much amps" (youtube is full of these). The key is research tbh.