I am new to solar energy solutions, but since power outages have become frequent in my area I have purchase a solar generator. Need some guidance determining the panels arrangement. Per my research I know I need to consider the solar input limits of my generator, in my case a Delta 2 with input limits 11-60V, 15A, 500W max. I know that for panels in series should consider voltage and in parallel current. My confusion is that some say to consider panel’s Vmp and others Voc for voltage, and for current some say consider panel’s Isc and others Imp. Also, other say consider voltage and wattage only, current is normally regulated my the charge controller. Can someone please clarify which specific parameters I should consider for series connection, parallel or series/parallel? If is true that the input current is not that important as voltage in this application? I will appreciate all the detail information that can be provided, since I am a beginner. Thanks in advance.
How to Determine Solar Panel Arrangement
- Thread starter ilaboy
- Start date
littleharbor2
Solar Addict
Without getting into all the details in your post, I see this "solar Generator " has a 1024 wh. capacity. That is 1 kw. Even if all one kw is usable that isn't enough power to cover any significant grid down loads. Before you start spending money on equipment you need to define your critical loads and amount of time you expect to be able to power them.
jvin248
New Member
- Joined
- Sep 5, 2022
- Messages
- 17
.
Does the generator just clip at "500W Max"? or trips a breaker at that point? Some builders are 'over paneling' their systems to get more energy in the morning and evening (solar power hits panels like a normal distribution bell curve, with the inverter clipping off the top of the bell), splitting the group of panels for some face more East, some more West will also pick up more energy am/pm while reducing mid-day where clipping may occur.
+1 figure out your loads. Refrigerator + a few lights are typical. Can you get a more efficient refrigerator (perhaps a 'dorm size' to hold critical things during the outage and a camping cooler with ice for other items)?
I have a deep well pump so that has been a problem (needs 240v), some have A/C systems they want to run.
.
Does the generator just clip at "500W Max"? or trips a breaker at that point? Some builders are 'over paneling' their systems to get more energy in the morning and evening (solar power hits panels like a normal distribution bell curve, with the inverter clipping off the top of the bell), splitting the group of panels for some face more East, some more West will also pick up more energy am/pm while reducing mid-day where clipping may occur.
+1 figure out your loads. Refrigerator + a few lights are typical. Can you get a more efficient refrigerator (perhaps a 'dorm size' to hold critical things during the outage and a camping cooler with ice for other items)?
I have a deep well pump so that has been a problem (needs 240v), some have A/C systems they want to run.
.
When you put panels in series the voltage adds. You have a 60v max input. Stay below that. So if you have panels with a Voc (look at sticker on the back or the specs when purchasing) of 20v, you can only put 2 in series. 3 in series would be 60v and when it gets cold, the Voc will go up, over what is printed for that panel. So stay below the max 60v.
When you put panels in parallel, the amps add up. More amps need heavier wire. Your charger is rated at 15amps. If you put 2, 8 amp panels in parallel, you will have 16amps available under ideal sun conditions (which doesn't normally happen). The charger will not create a load greater than 15amps, so having 16amps available is not a bad thing. You will just never see more than 15amps with that charger.
When you put panels in parallel, the amps add up. More amps need heavier wire. Your charger is rated at 15amps. If you put 2, 8 amp panels in parallel, you will have 16amps available under ideal sun conditions (which doesn't normally happen). The charger will not create a load greater than 15amps, so having 16amps available is not a bad thing. You will just never see more than 15amps with that charger.
Not sure what it does with more than 500w. Regarding the fridge I have a regular size one and an office size one. Thanks for the suggestions.
I understand. The voltage limit for series arrangement seems to be more critical than the current limit for parallel arrangement. In you example you mentioned 16 A if the limit is 15 A is ok, but how far it will be safe to go over the current limit?
The 15 amps is not so much of a limit as the rating. The charger creates a load (variable load under the charger's program logic). It can create a load of 15 amps (max). If you put in parallel 4 panels that at max power can cause 6 amps each to flow, under perfect sun conditions, with the proper load, you can get 24 amps. The key thing is that load must be such that the load causes the current to flow. If the load's equivalent resistance is high, there will be less amps, because the load is "light".
An MPPT charger will create a load that is dynamic so it can find and draw the best power from the panels. But as the current (amps) or the power (watts) approaches the rating of the charger, the charger's logic says, "that is enough load for what I can do" and the load hovers at the rating if the solar power is available. One of the other members posted about "clipping or tripping". You would expect to see clipping with an MPPT because they are all microprocessor based and run program code to do their jobs.
The idea of having more panel power than you can use is helpful with early and late sun (previously stated) and in cloudy conditions. If you have more panels than can be fully used, it can cause your device to run close to its rating for longer periods and more often than if you were undersized on the panels. So proper ventilation becomes very important.
