# Trying to figure out what to buy for my solar power system

My plan is to get 4x 250w panels @24v, 6x 12v 200 ah batteries, a 60 amp charge controller and 1000w pure sine inverter. It will be a 48v system. How does all of this scale with each other?

Also I don't have a clue if this will even work so any recommendation would be appreciated. I would like to get a good price/quality. I don't need the best but don't want something thats cheap and breaks in a year.

Also what kind of power capabilities will this setup provide? Can I run a heater at night or an AC all day? I don't expect it to but it would be nice. Or will I be limited to some lights and small appliances

• Welcome to Sustainable Living! Please note that shopping recommendations are off-topic here, that's why I removed that sentence from your question. Your question how things scale, or how much you can run with the described setup are fine. Dec 26, 2015 at 11:28
• Your power use questions ... "no". A heater is typically at least 1kW, so for 12 hours overnight that's 12kWh. a 12V 200AH battery stores 2400Wh = 2.4kWh, so 6 of those is also 12kWh. But that means you can't have any losses in your system, like from an inverter or batteries that are less than perfect. Unfortunately the usable discharge from a lead-acid battery is between 20% and 80% depending on how many cycles you want, deeper discharge meaning fewer cycles. 100% discharge means 1-5 cycles then replace the batteries.
– Ⴖuі
Dec 28, 2015 at 20:43
• There are lots of solar calculators online that can help you plan a system. Without knowing what your projected load and usage patterns will be, no one can tell you if the system you've spec'ed out is adequate. Dec 29, 2015 at 3:32
• Calculations of power required, together with its variation during a work day/week/year, are inputs necessary to give meaningful advice. After that, tell us what area you have available for the panels, in which direction they are facing, what amount of sunshine you have during the year. Only when these two blocks of information are present you can start looking at what type and size of equipment you will need, and after that, what is available. It seems as if you are missing some steps and immediately jump to the last one ;-) That is why "I don't have a clue".
– user2451
Apr 16, 2016 at 13:25
• So get to work ;-), edit the necessary information into the question, so people can help you further. You may even want to divide your research into several steps and ask specific questions about those.
– user2451
Apr 16, 2016 at 13:27

## 2 Answers

This proposed system wouldn't work as described. With the quantity of batteries, panels, and your inverter that you've described, the system size would be - 1kW solar, 14.4kWh batteries @48V (see note below), and 1kW inverter.

The biggest and most obvious problem you can't wire a 48V battery bank with six 12V batteries. To make a 48V battery bank with 12V batteries, you need to wire them in sets of 4, so you could have 4 or 8 but not 6. (When you fix this problem, your battery's kWh will change.)

A 60A charge controller would be way overkill. Depending on if you were to go with MPPT or PWM, you would only need between 20A to 30A but there is no harm in going with a larger one in case you want to have room for expansion.

This would make a nice solar system for a camping trailer, or for a remote cabin where the only thing you needed were a few lights. This wouldn't run heaters or a/c but it would have no problem with running the fan on a gas powered trailer furnace. You might be able to run a couple of power tools as well on a good sunny day but that 1kW inverter might be a bit limiting. This is about the size I'm considering installing on top of my work truck but I will go with 2kW inverter so I can run a big compressor in case I ever need to.

The normal way to go about sizing a system is to figure out what you want it to do and then try to size it to meet the need. Both Johnny's and Ⴖuі's comments have good info.

After further research and understanding all this a bit better, I think I've decided my finished set-up will be:

• 24 250W 24V Renology panels
• 2 3000W Cotek sine inverters
• 2 Morning Star 60 Amp MPPT controllers, and
• 8 400Ah-500Ah batteries (although I'm not sure what brand to get).

Also, this will be for full off-grid use in Colorado and I've decided I'm just gonna go with a wood burner for heat; not sure about A/C. I think this should work for my needs and more. I still don't know if there's anything better I could do or not, though.

• This answer doesn't really seem to provide a good answer to your own question, so it may be downvoted or removed. I think it would be best if you edit this extra information into your question (just click on the 'edit' option below the question post). Dec 26, 2015 at 11:30
• So you've gone from a \$2500 system to a \$25000 system? Is this even a real question? That's an awfully big jump in system cost with no justification for the system size... along with ongoing costs as batteries need replaced periodically. At peak power your panels will put out a total of 250A of current (@24V), so your inverters and charge controller seem way underspec'ed. If you're serious about building this system, find a local solar integrator that can help you size the system appropriately otherwise you may end up thrown a lot of money at something that won't give you the power you need. Dec 29, 2015 at 3:39