Re:Ask HN: What is the best small off-grid solar kit today?
by prmph on Saturday August 04, 2018 @03:58AM
(#17685878)
Thanks for this reply. Maybe I'm not understanding something, but 1kWh per day converts to about 42 Watts. Why would I need several 100W panels? Is the power rating of the panels a peak, before efficiency or lack-of-sun losses are taken into account?
Re:Ask HN: What is the best small off-grid solar kit today?
by odonnellryan on Saturday August 04, 2018 @08:43AM
(#17686642)
You only get real power out of your solar for a few hours a day, at best. This needs to be enough to supply power to your equipment during those hours while also (hopefully) giving your battery bank a full or near full charge.
Your panels will pretty-much work 24/7 though. I've gotten half an amp from the moon on my 2x 100w panels.
> Is the power rating of the panels a peak, before efficiency or lack-of-sun losses are taken into account?
Yeah. They can actually put out a tiny-bit more, but don't expect them to. Plan for them outputting peak 70% of what they are rated for, actually.
Re:Ask HN: What is the best small off-grid solar kit today?
by childintime on Friday August 03, 2018 @04:33PM
(#17683389)
What about those batteries, is lithium an option?
Re:Ask HN: What is the best small off-grid solar kit today?
by mikestew on Friday August 03, 2018 @05:01PM
(#17683574)
Get your wallet out. Your tissues, too, because what you're about to see is going to be eye-watering:
https://battlebornbatteries.com/
I looked at them for RV use, though, and folks seem to be happy with them. Too rich for my blood, I ended up going with AGM for now.
Oh, and they have kits, too. Just add solar panels:
https://battlebornbatteries.com/product-category/battle-born...
Re:Ask HN: What is the best small off-grid solar kit today?
by amerine on Friday August 03, 2018 @06:40PM
(#17684188)
Wow. ~$1k/100ah for those babies. Dang.
Re:Ask HN: What is the best small off-grid solar kit today?
by odonnellryan on Friday August 03, 2018 @09:20PM
(#17684870)
Sure! Just incredibly expensive.
1kWh is about 85 Amp Hours. You'll need at least a 160Ah battery if you don't want any extra storage. Usually you will need to at least double that for days when you don't have much sun. I would suggest you need at least 400Ah worth of batteries.
Then you have to figure out how much sun your panels are getting to determine if you can fully charge your batteries in that time for the rest of the day.
You'll most likely only need a few 100W panels. This means you'll be looking at <$1k for the batteries and <$1k for everything else, including a cheap controller.
Size? Well expect this entire thing to weigh around 500lbs!