Off grid cabin - Newbie

[Chuego]

Hi all,

been reading this forum and watching Will's videos.

Just got a cabin on lake Como, it has a tiny very old 12v system, think 100watt panel, only used for neon lights, radio, 12v fridge. 3 rooms and external light all cabled with 12v custom plugs. AGM battery is dead.

I'd like to build a new system that will allow me to power these lights and work remotely. Was thinking of buying four 190Ah 3.2v lifepo4 on alibaba, put them in parallel and following Will's post: on https://www.mobile-solarpower.com/2000-watt-24v-solar-system.html

Not sure it's enough though, would like your input, this is what I need it for:

• MacBook + Monitor
• Wifi+LTE router
• 12v fridge
• Cell phone
• Makita charger

Need to add a pump, uv sanitizer
Gets a little cold here, below 0c for about 2 months.
I have a generator as well.
Cabin I get to it by foot, so all the stuff I buy I need to bring up by hand.

Wanted some help to understand if 24v is the way to go and if you think battery bank is enough.

Thanks for your help

 

[kernel]

2000w is a nice cabin system. If you dont want to have to have 200A (sarc) worth of charge control 24v is great.

You could go all ac or use a converter for 12V these are nice because they place low voltage disconnect on your dc stuff and keep voltage at 13.8 instead of 14 and 15 volts sometimes or 9V!

After 2000W 24 volt is a blessing. 5000W at 12V only if you have to.

 

[SCClockDr]

24 volt battery system would help minimize wire costs & improve inverter efficiency if you want to use one. The more items you can keep on DC the more efficient your build will be.

 

[kernel]

24 volt battery system would help minimize wire costs & improve inverter efficiency if you want to use one. The more items you can keep on DC the more efficient your build will be.

Converter losses can be equivalent to (in)verter losses.*

 

[SCClockDr]

You will need to do an energy audit for each of the items you listed.
A preliminary audit would be to use the label specs & guesstimate usage.
A better more accurate audit is to monitor actual daily consumption for your normal usage & add a safety factor.

 

[kernel]

Converter losses can be equivalent to (in)verter losses.*

Nice comment about being nearer inverter output voltage to start!

 

[SCClockDr]

Converter losses can be equivalent to (in)verter losses.*

Dual conversion is where the losses add up. ( DC> inverter>wallwart>router)
Also DC lighting can be hooked in series to operate on 24VDC.

 

[kernel]

Yes, an extra hop vs converter. Converters have tiny, tiny no load consumption and operate as efficiently as a good inverter. An inverter on all day might consume as much or more than a high efficiency fridge.

Most houses off grid are no longer having systems that look like 1x 50W panel and a car battery with tail lights in the lamps. (Thats not a slight on your comment.)

Convienience could be worth the extra watt/hrs consumption afforded by 50 cent/Watt modules.

Our cups runneth over!

 

[BigVT]

Just a thought re router, I settled myself for a Teltonika 950 that accept power (9-36v) through Power over Ethernet (PoE). It's just adding a passive POE injector that's super cheap and avoids the extra conversion.

 

[kernel]

I use poe liberally right from the 24v bus baby...

 

[Chuego]

Thanks guys! Lots of feedback, I'm convinced will go the 24v route

So I will do a energy audit and also try to keep as much on DC as possible.

Internal lighting I can cable that in series and do 24vdc and find a 24v pump and UV sanitizer.

Thanks for the tip on POE + router so I would just need an injector for the router, maybe I'll get a rasberry pi on POE as well.

Panels was thinking buying four 300w Peimar mono.

Thanks again