[RE-wrenches] PV voltage at Isc

2011-02-05 Thread Greg Egan
Fellow Scientists, I got in a discussion with a wrench the other day. He is under the impression that when a PV module is at short circuit current there is no voltage. My understanding of electricity is that if there's no voltage there's no current because current needs voltage in order to f

Re: [RE-wrenches] PV voltage at Isc

2011-02-05 Thread Kent Osterberg
Greg, All circuits we are working with have resistance and therefore voltage is required in the circuit. With a shorted module most of the resistance, and voltage, is within the module itself. A superconductor could be used externally, connected as close to the module as you like, and there wo

Re: [RE-wrenches] PV voltage at Isc

2011-02-05 Thread Exeltech
Greg, Great question. All power generators and energy storage devices (batteries, capacitors, etc.) have what's termed "internal resistance", also termed "internal impedance" when frequency greater than DC is involved.  This resistance/impedance is what limits the output current of these devic

Re: [RE-wrenches] PV voltage at Isc

2011-02-05 Thread boB Gudgel
On 2/5/2011 11:30 AM, Greg Egan wrote: Fellow Scientists, I got in a discussion with a wrench the other day. He is under the impression that when a PV module is at short circuit current there is no voltage. My understanding of electricity is that if there's no voltage there's no current bec