4 minutes ago, Don said:

Very confusing.

I worked from a rule of thumb, I didn't look at the spec sheet. The average 72-cell that I'm used to make around 45V open circuit, so 3 in series will be safe. In addition they make at least 30V at low light, which is still enough to make a tiny bit of charge. So the average 72-cell panel should work 2-wide of 3-wide. But these panels with their 54Voc seems to be from another world... :-)

My MPPT stats is for the BlueSolar which is what I think he's looking at. It has an absolute limit of 150V, and cuts out at 145V.

In the end, it's Caveat Emptor. The buyer must read his own spec sheets :-)

3 minutes ago, plonkster said:

The buyer must read his own spec sheets :-)

That was my whole point of posting. Now he knows what to look for and say, hey, looking at the spec sheet 2 panels will work. I will install them. 

Just now, Don said:

That was my whole point of posting. Now he knows what to look for and say, hey, looking at the spec sheet 2 panels will work. I will install them. 

So it all worked out in the end :-)

@Richwost, in the Example I posted, I used 315 Watt panels, NOT the panels you were referring to, nor the Inverter you are currently looking at. In that post I tried to make a point that 2 panels will not be sufficient, looking at the data sheets I posted, and why and at the same time what to look for when buying inverters or panels.

As @plonkster and @SilverNodashi pointed out, the Solar Panels you referred to in your post would actually work and I agree with them.

So to answer your question, yes, 2 of those super duper Sunpower panels will work.

Good evening gentlemen,

Many thanks for your unbelievable contribution to my dilemma.  You may have silenced me, but not for long!!  I take on board the 'caveat emptor' comment and also the extremely complicated nature of this beast called Solar Power as enunceated by Don in particular.  Because of the number of conflicting comments that followed, I have come to realise that I must become better informed about voc's, absolute limits, open circuits and other Greek that makes the Latin I studied at school seem like child's play.

I will do my homework and come back with a proposed solution OR - and more likely - more questions!!  That OK?  

36 minutes ago, Richwost said:

That OK?

Any time.

On the forum we panel beat any proposal into a working solution.