Real Beginner- Have some components, need a few details to take the last steps.

[atomj123]

Hello,
This is my first post on the forum. I have been interested in solar power since I did a project on it in middle school in the 80's-early 90's. My best friend has a huge setup (installed by the former owner, and his current neighbor). I have tried to get the neighbor to help, but he is very busy. I helped my friend install his second system (but only physical install, not technical). I have a Ph.D. in biochemistry, so I have taken plenty of electrochemistry, physics and chemistry courses to understand the science. But my knowledge of the application and engineering of the systems is limited/rusty (don't tell my college physics professor . I, also, have a decent knowledge of electrical work and I used to repair electronics. The internet has helped, but I need to understand it better.
Most of the "how to start" content on the internet is: what are you trying to do/power, then build to those specs. Well, I found new materials (still in unopened box) on an online auction and purchased them at a great price (compared to their website). So, right off the bat, I am starting the wrong way. I know I need a solar controller, batteries, inverter, solar panels, fuses, a sub panel, and probably more. I will give the specs of what components I have currently.

Solar panel: 1x - Sungold 200W 24V panel, grade A Panel on their website CLOSEST to what I have (didn't have instructions/manual, just what was written on the box)
Inverter/Charger: 1x - Sungold LFP Series, Pure Sine wave Inverter charger6048D GFCI. I think it is a 6000W 48V . one on the website CLOSEST to what I have (I think there are a few differences- model # is different)
The manual says:
Charging: Input voltage range: Narrow: 100~135Vac/ 194~243Vac Wide: 90~135Vac/ 164~243Vac; with 60+/- 5 A max charging.
Inverter: Nominal Output voltage: 100-110-120Vac / 220-230-240Vac; Output frequency: 50/60Hz; Has current limit function; full bridge topology, with AC priority.
DC input: Nominal input V: 12.0Vdc (*2 for 24Vdc, *4 for 48Vdc); minimum start V: 10.0Vdc; (and they recommend AWG 1/0 wire for the connections to the battery).

I will be moving within 2 years, so I do not want a grid-integrated system. I want an off grid system, just in my garage that can run an AC or heater, that I can take and upgrade to power a separate garage/workshop. (I really just want to generate power, and learn the finer details of building/upgrading these systems.) I went to a forum on reddit and I just got a bunch of replies that said just buy a all-in-one "Harbor freight-like" system and generate power and figure out details when you are really serious. I then searched online and didn't quite get confident enough to buy the rest of the components (I have only recently starting looking at beginner stuff on this forum, but there is so much, my searches haven't found the right info to get started). I even messaged the company with what items I have and didn't get a reply at all. Now, I am sitting here 1.5 years in and have a few components and a panel not doing any solar work.

1. Is it ok to use a 24V panel with this inverter?
2. What type of battery (voltage/current) should I look for?
3. The solar controller that I get, should it match the voltage of the panel or inverter?
4. The manual has a "charger breaker rating" 30A. Is that the rating of breaker I use between the inverter/charger and battery?
5. When designing these systems, do you match components to voltage/ current/ power? I want guidance/a tutorial on how to pick the components, not just "what's the work/power demand? Well here's the system you want?"

Any guidance on how to fit my, seemingly, square components into a round hole would be great. I am willing to switch out any components if I need to, but I just want to know why. I have a light budget and are interested in Macgyvered solutions (as long as they don't zap me or my garage- my wife would be upset).

Thanks for listening,
Atomj123

 

[MikeInKingman]

Your Inverter is 48V, so that is what your Battery Bank Voltage must be to feed it.

The Charge Controller is based on your Battery Bank Voltage.

Order of things....Pick a Battery Bank Voltage (12v, 24v or 48v). Pick a battery Chemistry and amount of Amp Hour Capacity. Determine how much Solar you need to recharge a Battery Bank of that size. Pick Charge Controller of sufficient size to accommodate the required amount of Solar.

To determining the size of your Battery Bank in AH's, you'll need to determine what you total electrical load will be...which will also allow you to size the Inverter based on maximum simultaneous Load Demand from things you are trying to power from the battery/inverter.

Just some basics...others should be along to help more.
Stay Safe.

 

[sunshine_eggo]

1. Not typically. In almost all cases, your PV voltage must be higher than your battery voltage by some noteworthy amount - depending on charger controller. "24V" does not mean the panel outputs 24V. It means it has 72 cells with a Voc of around 45V and a Vmp around 36V.
2. 48V lead acid or 51.2V LFP.
3. It must be capable of acting as a 48V charger for your 48V battery. Since you only have a single panel, there are boost MPPTs that will take lower voltage PV and boost it to battery voltage.
4. Hard to say without additional context.
5. Yes. Please see the energy audit in line #1 of my signature.

 

[Rednecktek]

6: A single 200w panel will not be able to charge the battery enough to break even for what the inverter needs to operate, somewhere in the 60w range × 24 hours. That's near 1500wh which would require a 200w panel in PERFECT conditions to have 8 hours a day of PERFECT sun just to hope to break even on the inverter. Nothing left for loads after that.

 

[sunshine_eggo]

6: A single 200w panel will not be able to charge the battery enough to break even for what the inverter needs to operate, somewhere in the 60w range × 24 hours. That's near 1500wh which would require a 200w panel in PERFECT conditions to have 8 hours a day of PERFECT sun just to hope to break even on the inverter. Nothing left for loads after that.

This is an excellent point. The burn on those units is closer to 100W, so inverter consumption will be closer to 2.4kWh needing even more than 200W.

 

[Glock24]

Also keep in mind that you won't get the rating written on the panel's label, you'll most likely get around 80% of that.

So a 200W panel will output around 160W.

For anything useful you'll need more than a single panel.

 

[atomj123]

Your Inverter is 48V, so that is what your Battery Bank Voltage must be to feed it.

The Charge Controller is based on your Battery Bank Voltage.

Order of things....Pick a Battery Bank Voltage (12v, 24v or 48v). Pick a battery Chemistry and amount of Amp Hour Capacity. Determine how much Solar you need to recharge a Battery Bank of that size. Pick Charge Controller of sufficient size to accommodate the required amount of Solar.

To determining the size of your Battery Bank in AH's, you'll need to determine what you total electrical load will be...which will also allow you to size the Inverter based on maximum simultaneous Load Demand from things you are trying to power from the battery/inverter.

Just some basics...others should be along to help more.
Stay Safe.

many thanks. This info helps me a bunch.

 

[Flunkyboi]

I'm a noob that just built my first system. I also started bass-ackwards. With me, it was lucking into a bunch of panels (culls from a solar farm that i studied and figured out how to fix them). Then I decided to build a little solar generator shack to learn with and use.

Sounds like your backwards entry already has awesome equipment to start a plan with. If that's the Sungold AIO 48v (all in one MPPT Charge Control/5000w AC inverter) I'm thinking of, you scored well.

Half the learning in this forum is learning all the acronyms and Ohm's Law. You mentioned being a Piled High and Deeper. I'm sure you got this with some study.

Aside from reading a ton of threads here, i suggest two books. One is Will Prowse's (this is his forum) and one by that Nick guy from the Clever Solar. Reading those both helped me catch up to speed.

Also, this forum is a wealth of old threads. Just type in a keyword and look down at "Similar Threads" box below. Your questions have likely been covered before.

 

[Flunkyboi]

Also keep in mind that you won't get the rating written on the panel's label, you'll most likely get around 80% of that.

So a 200W panel will output around 160W.

For anything useful you'll need more than a single panel.

Good rule of thumb, but i saw my little 2430w array ripping at 2440w the other day...and it was 75° with zero backlighting on those bifacials.

I'm not bragging, but i kind of am.

 

[mikefitz]

1. Is it ok to use a 24V panel with this inverter?

The inverter is specified for a 48 volt battery, its an inverter/charger only and does not have the charge controller function needed for a solar panel. This will need a seperate controller that will 'usually' need a solar array with a output voltage higher than 65 volts for a 48 volt system.

2. What type of battery (voltage/current) should I look for?

A 48 volt battery. A typical lithium 48 volt battery, nominal volts 51, examples,

https://www.litime.com/collections/48v-batteries.

If you want to run the inverter at full power, the battery, or battery pack, needs to supply around 130 amps. If you start with a 100Ah battery with 100A output, the AC load will be limited to under 5000 watts and supply 5000 watts for one hour, or proportionally, example 1000 watts for 5 hours.

3. The solar controller that I get, should it match the voltage of the panel or inverter?

The output should match the battery and inverter rating, 48 volts in this case.
The panel array voltage needs to be higher than battery charge voltage. The controller will have a maximum allowed PV input limit and a design maximum output current limit.
For example a Victron controller 150/35 will accept a panel array, ( a set of series/parallel panels) up to 150 volts. For example, a 1000 watt array in ideal conditions will produce a nominal charge current of 18 amps.

4. The manual has a "charger breaker rating" 30A.

This is for the AC feed. The DC connection to the battery will need a class T fuse rated at 150 amps.

5. When designing these systems, do you match components to voltage/ current/ power? I

Decide the power, watts, you need, and for how long, watt hours.
Idealy you need to limit the DC current the current flowing in the system to under 100 amps.
Thus for a small system with an inverter, a 12v system is limited to 1500 watts. For domestic applications once above 2000 watts a 48 volt system is ideal.
The battery capacity determines how long you can power the loads without solar contribution.
The amount of solar required has to keep up with load demand.

 

[Glock24]

Good rule of thumb, but i saw my little 2430w array ripping at 2440w the other day...and it was 75° with zero backlighting on those bifacials.

I'm not bragging, but i kind of am.

Under some conditions the panels will give you their rated output and sometimes even more. But average continuous output will be lower.

 

[sunshine_eggo]

Good rule of thumb, but i saw my little 2430w array ripping at 2440w the other day...and it was 75° with zero backlighting on those bifacials.

I'm not bragging, but i kind of am.

Sustained output or cloudy conditions. If cloudy, like edge effect. I've seen 3700W out of 2970W with cold temps and cloud edging.

Thread 'I'm the luckiest boy in the world!'

Feb 3, 2022

"You'll never see max power out of an array."

I've said that dozens of times. Sometimes, my pants are on fire!

AZ. Panels tilted at 29.5° at Azimuth 165° (peak solar is at about 11:30am). Only ~6 weeks out from the Winter solstice, which is the worst day of the year for solar.

Here's what I got today...



Red line indicates array rating. Choppiness was due to clouds. The big peak was cloud edging, but there was more at work than that...

6500 ft elevation - closer to the sun and 22% less atmosphere.
Today made a witch's tit look snuggly and warm - overnight was single digit...

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