How to lower amps and raise volts from parallel pv arrays to cope with shade? I'm confused.

[Newsolarguy75]

Hi,

I've been trying to find a solution to my problem of being limited to small series panel strings due to shade issues. So I have lots of small arrays dotted around my garden. To be precise I now have arranged them so that I have 6 strings of 3x175w in series. The output is around VOC 63 and Amps 9ish for each string.

I tried putting them all into a 6 into 1 mc4 combiner but the AMPs is then very high and at certain parts of the day I'm losing out on lots of solar energy.

Is the some device I can plug them all into and then step up the volts and step down the amps before feeding to my mttp controller ?

I guess some device where you program in say max amps 15 and it then takes the energy as it comes in a bumps up the volts as required to stay under 15 or at 15 amps?

I found some very small things called buck booster but they only handle tiny energy like 5amps.

How can I solve this issue? Or is there an mttp controller that can take maybe 60 or 100amps solar Pv input?

I was told generally mttp contollers are designed to step down V to A not the other way around.

Would be great to find some device where I can plug in all my solar energy and dial down the amps to a level that my mttp can optimally use.

Does such a device exist for larger than 5amps or 90v? Is there a name for it other than step up or buck booster? I saw a digital step up booster which you could set but it needed stable input to convert which with solar pv input is impossible.

I think I need something like an mttp which is made to step up volts and step down amps? Then send that to my bluetti or new growatt or mpp solar set up. It's a shame their input pv amps are set lower than 80-100amps. I could add more solar arrays in other spots but the combined amps is growing out of control.

Thanks for any ideas how to solve this.

 

[Goboatingnow]

Why do you want to step up the panel voltage. ? Is your panel voltage falling below your battery voltage due to shade. If so you need to break into more parallel strings and more mppt controllers.

I presume your panels have bypass diodes.

For proper mppt range your panel Voc should be at least double your battery voltage

 

[Newsolarguy75]

Why do you want to step up the panel voltage. ? Is your panel voltage falling below your battery voltage due to shade. If so you need to break into more parallel strings and more mppt controllers.

I presume your panels have bypass diodes.

For proper mppt range your panel Voc should be at least double your battery voltage

Hi, thanks for your reply.

My main problem is that with combining so many strings in parallel my combined amps are growing to near 60amps and will be at 80amps with my new strings. I though maybe a device to lower amps and just raise the V would be possible.

I think though maybe you told me the answer I need to use more mttp controllers to feed a central battery bank. I was hoping maybe there was one mttp that could take large amps from PV but maybe linking multiple mttp wont be hard once I study it.

Yes my solar panels I think have bypass diodes they are renogy 175w.

Thanks.

 

[Goboatingnow]

Hi, thanks for your reply.

My main problem is that with combining so many strings in parallel my combined amps are growing to near 60amps and will be at 80amps with my new strings. I though maybe a device to lower amps and just raise the V would be possible.

I think though maybe you told me the answer I need to use more mttp controllers to feed a central battery bank. I was hoping maybe there was one mttp that could take large amps from PV but maybe linking multiple mttp wont be hard once I study it.

Yes my solar panels I think have bypass diodes they are renogy 175w.

Thanks.

Yes high power dc dc converters are expensive and rare. Just use more suitably rated mppt units.

This is why a like the micro invertor tech

 

[Newsolarguy75]

Yes high power dc dc converters are expensive and rare. Just use more suitably rated mppt units.

This is why a like the micro invertor tech

Thanks for help. I now know to forget finding such a device and just find either the mttp withheld highest pv amp receiver or link multiple mttp controllers.

Just in case anyone reads this that knows of an mttp controller that can handle 60 to 100amps Pv input then please can you post the make and model.

I was about to buy the 11kw mpp solar hybrid but that only has a 12amp PV input so that will mean I need a new mttp for each string. That may not be a problem though if they are simple to link together. At first I thought It had a 150amp solar input but that seems on further reading to mean the rate it can charge the batteries from solar. So it must be stepping down the large voltage it can accept.

Thanks.

 

[12VoltInstalls]

Just in case anyone reads this that knows of an mttp controller that can handle 60 to 100amps Pv input then please can you post the make and model

I’d just use two SCCs and increase numbers of series panels to raise volts and cut down on amps.
Is this lithium or lead batteries?

My main problem is that with combining so many strings in parallel my combined amps are growing to near 60amps and will be at 80amps with my new strings

I’d group them to safe low-temp corrected VOC and start abandoning so many parallel parts.

 

[Supervstech]

Thanks for help. I now know to forget finding such a device and just find either the mttp withheld highest pv amp receiver or link multiple mttp controllers.

Just in case anyone reads this that knows of an mttp controller that can handle 60 to 100amps Pv input then please can you post the make and model.

I was about to buy the 11kw mpp solar hybrid but that only has a 12amp PV input so that will mean I need a new mttp for each string. That may not be a problem though if they are simple to link together. At first I thought It had a 150amp solar input but that seems on further reading to mean the rate it can charge the batteries from solar. So it must be stepping down the large voltage it can accept.

Thanks.

Even if such a device existed, it wouldn't solve the problem.

If the amps are too high, then the watts are too high for the controller.

More controllers, or a bigger controller is the answer.

 

[Goboatingnow]

Even if such a device existed, it wouldn't solve the problem.

If the amps are too high, then the watts are too high for the controller.

More controllers, or a bigger controller is the answer.

Well no actually of I have a 100/50 and I have a stack of parallel panels as the OP has and I’m exceeding 50 A , ( say at 24v panel ) then a dc dc converter would allow me to utilise the mppt controller better while retaining the parallel config.

 

[Al D]

Well no actually of I have a 100/50 and I have a stack of parallel panels as the OP has and I’m exceeding 50 A , ( say at 24v panel ) then a dc dc converter would allow me to utilise the mppt controller better while retaining the parallel config.

Supervstech was speaking to the power tolerance of the charge controller. Each charge controller has a maximum input regarding voltage, current, and power. It's likely that a CC maxed out on current and low on voltage will be over the power limit. Checking the spec sheet will give the appropriate inputs for max power production.