PV Gap

Mary Said:

There are 4 solar panels: connected to 4 single phase inverters: Then they goes to Combiner panel to feed?

We Answered:

Hi Da Sahar, there are only two options here. The first and most common is each panel feeds its own single phase grid tied inverter, and each inverter is connected independently through its own circuit to one leg of the three phase circuit breaker panel. In any building using 3 phase power, there are always single phase loads, such as the lighting, small electronics, plug in tools and appliances and so on. There is no problem with each ot the three legs providing different amounts of power at different times, it is very common. It works both ways, if you have 3 inverters each feeding one of the three legs, and one shuts down, the other two continue to work, the difference is absorbed at the utility transformer. There is no combiner in this arrangement, the three grid tied inverters, or four as the case may be all work independently. They might all feed back into a common junction box where three phase power is connected, but each inverter connects to its own phase, they don't talk to each other or balance each others phase out. If a fourth set is installed as well, it can feed any of the 3 phases as well, again, the utility transformer evens it out back on the grid line.

If you want to run a 3 phase load, then you have to have all your panels feeding into one 3 phase inverter, and the phase balancing is done internally in the inverter. That type inverter is not common, and is quite expensive, but they do exist. The only place something like this makes sense is in a 3 phase generator application where the inverter power parallels with the genny to take some of the load. If you have 3 phase grid power, there would be no reason to use a 3 phase grid tied inverter, since 3 smaller single phase inverters would accomplish the same thing for less money, unless you also wanted to run a battery based system that could continue feeding your loads should the grid go down.

If you do in fact have 4 separate inverters you want to grid tie, and they are certified to tie to the grid, just run a small 15 amp circuit, single phase, to each inverter from your main panel, and let them each independently talk to the grid. You might find an article or two about this in Home Power Magazine, they cover lots of unusual applications like this. If you subscribe online, you can use their search engine to look for something in all their back issues that will explain how someone did exactly what you are trying to do now. I'll include the link below and a few others you might find interesting. Good luck, and take care, Rudydoo

Douglas Said:

solar panels and inverters?

We Answered:

Solar panels convert light into electrical energy.

Inverters change the state of electrical energy. IE: DC to AC

George Said:

i need an inverter for solar panels, is there any specific inverters or i can use any inverter?

We Answered:

Depends on what you are trying to energize, how big your solar system is, etc. Check with a Professional as there are a lot of products out there and you don't want to buy the wrong one...or buy one if you don't need to. Look into a company called Sun Electronics. My uncle used them for a big retro fit on his house in the Florida Keys and my In Laws used them for a small project on their house outside of Chicago. Both my in laws and uncle happen to be BEYOND cheap and had Sun design their system, they did not feel as if they were getting ripped off, and most of all are enjoying their lower electrical bills!

Good Luck

Rodney Said:

ohm's law applied in real apps of solar panels, wind motors,inverters - if 12v generated and 1 ohm across, is?

We Answered:

your wording is difficult to understand.

"if 12v generated and 1 ohm across, is?" means what?

A 9 volt battery could produce 9 amps if it were powerful enough. the small rectangular ones are not, they have an internal resistance of perhaps 10 ohms. But if you put 6 D cells together to make 9 volts, it could easily put out 9 amps.

Some solar panels can put out 12 amps. At 12 volts, that is 144 watts, and would be a quite large panel.

In other words, batteries, and solar panels, have an internal resistance that adds to the load resistance and limits the current available.

.

Lauren Said:

question about inverters, PIE, and solar panels?

We Answered:

so, lets say you have a refrigerator that needs 445 watts while it is running, that 4 amps at 110 volts. So the solar panels put in the first 45 watts, leaving the other 400 watts from the battery. BUT now the battery is at 12 volts, so 400/12 is 33 amps. this means that your battery has to send out 33 amps plus 10% for losses) or 46 amps. If the battery was fully charged, you could run you refrigerator for 400 amp-hr/36 amps or 11 hours.