Test run with a small system first?

[SSC00]

Before I do any any serious system on my house, i want to run a trial to get experience with a smaller system to ensure I know what i am doing and so I can get comfortable with the different components and the wiring. I have been looking around at different smaller kits or equipment and I am not sure what the best approach is to learn. I could just buy a kit that has everything properly sized in it or I could just throw a bunch of components together to do it. Or maybe seeking to get a small system first to learn is unnecessary. I am not sure. I am open to all recommendations

As far as I can tell, for any system you need:

• Solar Panels
• Solar Charge controller - which connects to battery (and inverter?)
• Fuses/breakers to prevent any component from getting overloaded
• Battery
• Inverter
• wires to connect everything
• BMS if not on battery and some kind of system monitor to keep track of what is generated.
• Combiner box if you have a bunch of panel strings in parallel or something

Does this list look correct?

As far as wiring goes, lets say you have 12 panels rated at 12V and 100 watts. To have a 12V system, I would just wire them all up in series and get 1,200 watts of power at 12V right and to get a 24V system I would just wire up 6 panels in series with 2 parallel rows and it would give 600 watts of power. Both systems would be 100 amps. Am I understanding this properly?

To size the charge controller, I have to make sure that the controller has the appropriate amp rating. Taking the example from before, the charge controller would need to be 100 amps minimum right? In theory I could take a 475 watt panel at 54V and use it with a 20 amp charge controller (something about that doesn't seem right)?

With inverters, is the watt rating the output watts in AC? So a 3000 watt inverter at 24V would output 3000 watts AC but can only receive 24V DC?

With fuses, if the example system is all technically 100 amps, I would need 100 amp fuses between the different components to protect them right?

Do all solar panels have the same connector (MPPT correct?)

for system monitoring, i dont always see to many options and it seems like inverters do it too. That is confusing to me as well.

I am in the southeast US and we supposedly get an average of 4.5 full sun hours where i am. If I had a panel that was rated at 100 watts, would that mean I could expect an average of 4.5 hours of 100 watt power generation from the panel? This has never been clear to me. (that would mean that a 500 watt system could produce an average of 2.25 kwh a day)

 

[Hogheavenfarm]

Watch a few of Wills videos, under "DIY Solar Videos" tab at the top.

 

[45North]

Good idea!
That was my approach too.

 

[SSC00]

Watch a few of Wills videos, under "DIY Solar Videos" tab at the top.

I have watched several and just want to make sure i am understanding properly. I do not do electrical things by trade and I want to make sure I am getting it right

 

[SSC00]

Im sure there are other components too. I just haven't gotten that far yet

 

[SSC00]

Good idea!
That was my approach too.

Cool! Did you ever expand farther since trying a small system?

 

[Mattb4]

Several areas you will need to review.

In series voltage adds. In parallel current adds. Solar panels are rated in Voc and Vmp. Calling them 12v or 24v is rather meaningless. Always look up the panels specifications. SCC (Solar charge controllers) are often rated in Battery charging amps. However this is not the same thing as panel amps. Understand W=VA.

Most PV panels will come with a MC4 connector. MPPT is a type of SCC. Their rating is based on STC of 1000w/sqm of solar illumination of which the efficiency of ~20-23% will mean that a square meter panel is around 200-220 watts. The most likely scenario is the peak wattage will be about 75-80% of the rated wattage. Over the day this translate to the rated panel wattage times the amount of average sun hours. So yes a 100w panel in an area that has 4.5 hour average will mean you have 450wh.

 

[SSC00]

Several areas you will need to review.

In series voltage adds. In parallel current adds. Solar panels are rated in Voc and Vmp. Calling them 12v or 24v is rather meaningless. Always look up the panels specifications. SCC (Solar charge controllers) are often rated in Battery charging amps. However this is not the same thing as panel amps. Understand W=VA.

Most PV panels will come with a MC4 connector. MPPT is a type of SCC. Their rating is based on STC of 1000w/sqm of solar illumination of which the efficiency of ~20-23% will mean that a square meter panel is around 200-220 watts. The most likely scenario is the peak wattage will be about 75-80% of the rated wattage. Over the day this translate to the rated panel wattage times the amount of average sun hours. So yes a 100w panel in an area that has 4.5 hour average will mean you have 450wh.

ok. thank you! This is helpful. so this means that for solar panels, VOC is more important than some generic rating.

 

[SSC00]

Also, are used panels even worth it? Granted for my main system I will not get used panels because that seems like a bad idea but for a smaller learning system I dont really care.

 

[TomC4306]

I have 5920 watts of used panels.
Last 12 months they've produced 5.8 megawatt hours.
My calculations put these at about 88% retained capacity.
Especially if you can pick them up locally, I think they're a great deal. I got mine from a local solar installer.

 

[SSC00]

I have 5920 watts of used panels.
Last 12 months they've produced 5.8 megawatt hours.
My calculations put these at about 88% retained capacity.
Especially if you can pick them up locally, I think they're a great deal. I got mine from a local solar installer.

Nice. I doubt I would have that option since there isn't too much solar where i am. I would probably have to got to the next state over for something like that. I probably will ultimately get everything from signature solar for my main system, but for a learning system I will try anything (as long as it doesn't cost an arm and a leg lol).

 

[45North]

Cool! Did you ever expand farther since trying a small system?

No, didn't need to. I'm grid tied and was just doing it as a "hobby" to learn on. See my Sig for details.

 

[SSC00]

No, didn't need to. I'm grid tied and was just doing it as a "hobby" to learn on. See my Sig for details.

Ah. ok. Cool. I probably wouldn't do anything past 200-500watts to learn anyways unless i can do more for cheaper.

 

[Rednecktek]

Also, are used panels even worth it? Granted for my main system I will not get used panels because that seems like a bad idea but for a smaller learning system I dont really care.

Short answer? Yes.

Long answer? Yyyyeeeeessssss

I'm a big fan of telling people "If you might break something learning, break a CHEAP something!" Used panels are cheaper per watt than new panels by a wide margin, and getting more watts out of a single panel is less physical effort than getting 2 or 3 panels mounted for the same wattage.

Same goes for your SCC and inverter as well. No need to drop $$Victron$$ money when Rich Solar, PowMr, Giandel and WZRLB will do the same job at significantly less money.

Always check Craigslist and FacepageMarket for used panels you can get locally. Seeing online deals for $5 on a 600w panel sounds great until you see you have to drop $350+ on shipping for that one panel.

 

[SSC00]

Short answer? Yes.

Long answer? Yyyyeeeeessssss

I'm a big fan of telling people "If you might break something learning, break a CHEAP something!" Used panels are cheaper per watt than new panels by a wide margin, and getting more watts out of a single panel is less physical effort than getting 2 or 3 panels mounted for the same wattage.

Same goes for your SCC and inverter as well. No need to drop $$Victron$$ money when Rich Solar, PowMr, Giandel and WZRLB will do the same job at significantly less money.

Always check Craigslist and FacepageMarket for used panels you can get locally. Seeing online deals for $5 on a 600w panel sounds great until you see you have to drop $350+ on shipping for that one panel.

My sentiment exactly. For my actual system I want to make sure I do it right. I don't want everything to look extremely jerry rigged, but i need to learn on something. lol.

I live in the suburbs in the southeast. need it to look pretty if i ever have to sell the house. I doubt there are too many used panels near me since solar really hasn't picked up in my state.

 

[SSC00]

https://powmr.com/products/3000watt-220vac-24vdc-all-in-one-inverter-charger

Is this hybrid inverter only capable of putting out 230V AC? Just looking at their product line up, it seems like the hybrid inverters that are cheaper are the ones that can only output 230 V AC. Why is that? is it because of wire size inside unit or something? is there something about this form factor that kind of makes it not useful to have smaller capacity hybrid inverters for 120V AC?

Actually, why do they have so many 230V AC inverters? that seems like it would only be useful in a workshop or some really small off grid set up - (not sure how because with a really small set up few appliances would use 230V AC anyways)

1200W 12V 110V Solar Off Grid Power Inverter

1200W 12Vdc 110Vac Solar Off Grid Power Inverter for seamless energy conversion with advanced protection features. Ideal for uninterrupted power supply.

powmr.com

This inverter seems like it can accept 12V DC and a max amps of 112, but I would still put a 100 amp fuse for something like this.

I should be able to pair any charge controller with the batteries as long as the power output doesn't exceed what the inverter can handle i think.

 

[Mattb4]

Two reasons that the 230vAC 50hz AIO's and inverters are cheaper. Europe and Asia use that as their standard so a lot of market to sell to. Also as you noted higher voltage allows smaller conductors and less heat issues.

There are many smaller capacity 120vAC AIO's. Just need to search about. I run PowMr 3kW 120vAC high voltage PV units at the moment. 240vAC split phase (US standard) are also becoming much more common in the 6kW and up sizes although almost exclusively 48vDC battery.

I am also seeing a few 240vAC split phase mobile inverters on the market such as the WZRELB who has both 24vDC and 48vDC models ranging 2000w to 4000w.

 

[SSC00]

Two reasons that the 230vAC 50hz AIO's and inverters are cheaper. Europe and Asia use that as their standard so a lot of market to sell to. Also as you noted higher voltage allows smaller conductors and less heat issues.

There are many smaller capacity 120vAC AIO's. Just need to search about. I run PowMr 3kW 120vAC high voltage PV units at the moment. 240vAC split phase (US standard) are also becoming much more common in the 6kW and up sizes although almost exclusively 48vDC battery.

I am also seeing a few 240vAC split phase mobile inverters on the market such as the WZRELB who has both 24vDC and 48vDC models ranging 2000w to 4000w.

Oh that makes sense. I forgot that other markets use 230 as their standard voltage. So far I haven't really found a smaller cheaper AIO for 120v - not that an AIO is the best for a learners system, on the fence on this. In some ways its difficult for me to plan out a smaller system because its so easy for me to start adding up to more capacity. It seems like the the cost difference for the equipment to go from 1000W is not significantly less expensive than like 3000W - not including panels of course. To do it really cheap you would have to have a super tiny system - like 25-50 watts. But a system that small doesn't have the same types of consideration as a larger one.

 

[Mattb4]

It all depends on how much you want to spend but some things like a slightly more capable AIO will allow you to grow a bit. My advice for a system that will actually power real loads is a minimum of a 3kW AIO at 120vAC. With 3000kW it will run pretty much all standard plug in type 120vAC loads. The reason for the AIO is it will give you a lot more options with having grid as backup (GAB) to your setup. At minimum I would recommend at least 800w worth of PV and 2-3kWh worth of battery. Prices for that would likely put you just over the $1400 point.

 

[SSC00]

It all depends on how much you want to spend but some things like a slightly more capable AIO will allow you to grow a bit. My advice for a system that will actually power real loads is a minimum of a 3kW AIO at 120vAC. With 3000kW it will run pretty much all standard plug in type 120vAC loads. The reason for the AIO is it will give you a lot more options with having grid as backup (GAB) to your setup. At minimum I would recommend at least 800w worth of PV and 2-3kWh worth of battery. Prices for that would likely put you just over the $1400 point.

3kW would easily run all the lights and fans in my house. lol

oof. yeah true on that price. Seems to me that batteries would be the most expensive component anyways. Also, many of these sites have all these crazy looking deals all the time to encourage people to purchase things. lol its so hard knowing if the deals are good or not.

https://powmr.com/products/all-in-o...000w-110vac-24vdc?_pos=1&_fid=f9e9b6ced&_ss=c

This AIO here seems to be the cheapest. It seems like it would be cheaper than getting a stand alone inverter of a similar size and an appropriately sized charge controller too. Well, if it isn't cheaper, the cost should be similar. The site claims the unit can handle a maximum solar input of 4000W and a VoC max of 120-450V, which would require a ~30 amp fuse right?