PDA

View Full Version : Suggestions for use of 319V 100W Solar Panel?



Geegrrl
08-12-2013, 02:25 AM
I have recently acquired a 100Watt 319VDC (429VOC) flexible solar panel which I would like to use on my boat. I may buy more of these panels if I can find an affordable way to use them

The cost of high voltage MPPT controllers is prohibitively expensive with the Xantrex 80-600 at $1300 being the only one available that I know of....Therefore I was considering the following possiblities:

1. Go through a 230VAC UPS (UK model). "AC", input is quoted as 230V "RMS". That means a (sine wave) peak value of 230 x 1.414 Volts which is approx 325Volts. AC enters the SMPS through a filter and is rectified (turned to DC) and that voltage (325-ish minus a couple of volts across the rectifier) is stored on a "reservoir" capacitor. An input of 325V "DC" would amount to the same thing. Although perhaps the 429VOC would be a bit too overwhelming for the UPS which is designed for 230VAC UK mains power?

2. Use an invertor able to take this high dc voltage and convert to 230VAC UK mains voltage. Charge batteries from mains power. But is there a charge controller for the batteries which will run off of 230VAC?

3. Find a switch mode power supply able to convert 320VDC to 48VDC. So far I have not found any at an affordable price.

4.Cut the panels into 4 pieces and wire in parallel producing 80VDC. Use the cheaper 100V MPPT's.

What would people suggest?

Mike90250
08-12-2013, 02:51 AM
You WILL need a MPPT controller, or effectively neuter the panel to less than 100 watts. A conventional inverter will load the panel too much, and it's voltage will "collapse" and you get nothing at full sun. PV panels are CURRENT sources, and that makes a big difference.

Geegrrl
08-12-2013, 11:58 AM
effectively neuter the panel to less than 100 watts.

What do you mean by ""neuter?

Would cutting the panel into 4 pieces connected in parallel to produce 80VDC qualify as neutering? If so is the soldering of flexible amorphous cells as straightforward as regular cells?

Are there problems associated with DIY flexible cell soldering?

The 600VDC high voltage MPPT solution is just too pricey at $1300 plus shipping to the UK. Unless anyone knows of a less expensive one?

Mike90250
08-12-2013, 12:25 PM
What do you mean by ""neuter?

a) either find a PWM controller that can handle 300VDC without burning up (you loose 80% of the wattage this way, highly neutered)

b) pry open the junction box, and hope you can access the panel interconnects, and tap into them

Minute you take a knife to the backing and cut up the panel, you void the warranty, break the hermetic seal, and the death clock starts ticking on the panel.

Best is to trade it off for some normal panels.

You could possibly charge a 280V battery in the UPS, and get your AC from that. There may be a "crowbar" style regulator from a Wind Generator, that could operate in that voltage range to keep from overcharging the battery, if you cannot trade the panel for more normal ones, this would be your best hope. Something like 20ea, 20ah motorcycle batteries, might work, but what a pain to wire up and anchor down. And VERY dangerous voltages.