Hello, I am new here and looking for some information / advice on heating water (and air) from PV panels. I believe that I searched and looked through all the threads and could not find the information I was looking for so that is why I am posting a new thread.
I have a few tanks / elements that I have connected directly to PV panels and they all have the same kind of tendencies. Example:
If I hook up two 250W panels in series to a (standard) 208V 5000W element I get about 70V, 8A at the element. If I hook up two more,
Four 250W panels in series the voltage remains the same even though it should be close to 140V. I have done this with slightly smaller wattage (standard) 240V elements as well and it does the same thing.
I am wondering why I can not get any higher voltage out of the elements? If I have a 2000W element I would like to be able to know how to hook up 2000W (or close to it) of PV directly to it.
Any help would be appreciated, thank you.
Edit: I think I found the answer. It has to do with resistance and “matching” the source with the load. It is why MPPT charge controllers are more efficient. The PV panels (source) are constantly changing and constantly need matched to the load to put out full power.
I’m still not sure how to match the resistance between the source and load, but feel free to leave any comments, I’ll probably still learn something.
I have a few tanks / elements that I have connected directly to PV panels and they all have the same kind of tendencies. Example:
If I hook up two 250W panels in series to a (standard) 208V 5000W element I get about 70V, 8A at the element. If I hook up two more,
Four 250W panels in series the voltage remains the same even though it should be close to 140V. I have done this with slightly smaller wattage (standard) 240V elements as well and it does the same thing.
I am wondering why I can not get any higher voltage out of the elements? If I have a 2000W element I would like to be able to know how to hook up 2000W (or close to it) of PV directly to it.
Any help would be appreciated, thank you.
Edit: I think I found the answer. It has to do with resistance and “matching” the source with the load. It is why MPPT charge controllers are more efficient. The PV panels (source) are constantly changing and constantly need matched to the load to put out full power.
I’m still not sure how to match the resistance between the source and load, but feel free to leave any comments, I’ll probably still learn something.
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