[RE-wrenches] PV into a resistor: please advise

[jay peltz]

Hi mick

I'll take a stab

First one yes would work 
But the second would not as the watts don't equal the load so the resistor isn't the correct size any more

The LCB won't help because it won't make watts but amps to help start motors and this isn't a motor and it works in pulses which a constant load isn't impressed with but a motor is. 

You must have a reason to suggest such a "hypothetical " situation, no?


Jay
Peltz power

Sent from my iPad

On May 19, 2012, at 3:35 PM, Mick Abraham <mick at abrahamsolar.com> wrote:

> Hi, Wrenchies~
>  
> Kindly educate me regarding PV behavior when the load is a resistor. Here's a hypothetical situation:
>  
> * Eight 250 watt PV modules (60 cells per module), all connected in series for "peak" ratings of 240 volts DC & 8.3 amps 
>  
> * Lab type cell temperature & illumination so that the eight would truly pump 2,000 watts into an ideal load
>  
> * A 240 volt AC heating element designed for 2,000 watt heat dissipation at 240 volts AC...that's about 29 ohms resistance for the heat element
>  
> * Connect the PV string to the heat element, with nothing in between except a fused disconnect.
>  
> In the above situation, would the resistance of the heating element be all that's needed to force the PV array to operate near the "peak" wattage?
> Would the heater actually get 2,000 watts to turn into heat?
>  
> +++++++++++++++++++++++++++
>  
> Now consider the same cell temperature but half the illumination. That's similar voltage but half the amps at peak wattage. If this is sent into the same 29 ohm
> resistor--again with no intervening electronics, could we count on 1000 watts of heat?
>  
> If the answers come up "no", would the power throughput be helped by a SolarConverters style MPPT pump controller (Linear Current Booster kinda thing), assuming that one could be found to operate in the 240 volt range?
>  
> Thanks & Jolliness,
> 
> Mick Abraham, Proprietor
> www.abrahamsolar.com
> 
> Voice: 970-731-4675
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