How about a solar car port on a budget?

[Crossy]

The car port is really, really full now.

 

At least until ...

 

 

[Crossy]

So, we have a total of 28.8kWp spread over the three areas.

 

I've still got 2 x 540W and 1 x 340W panels spare.

 

Where to get them in ...

 

 

[Muhendis]

15 minutes ago, Crossy said:

So, we have a total of 28.8kWp spread over the three areas.

 

I've still got 2 x 540W and 1 x 340W panels spare.

 

Where to get them in ...

 

 

 

How's about making it a double decker ...........

[lom]

29 minutes ago, Crossy said:

So, we have a total of 28.8kWp spread over the three areas.

 

 

That a lot of unused energy, imagine if you could use all of that all of the day.. 

Are you planning to open an EV charging station for the neighborhood? 😉

[Muhendis]

2 minutes ago, lom said:

That a lot of unused energy, imagine if you could use all of that all of the day.. 😉

Would be good but don't forget that the amount of energy Crossy's potentially harvesting is not constant all day. The power output is quoted as 28.8kWp which only happens when the suns light  is perpendicular to the panels. But by any standards that's a lot of power.

Do you think it might might be a world record? 

[ExpatOilWorker]

43 minutes ago, Crossy said:

So, we have a total of 28.8kWp spread over the three areas.

 

I've still got 2 x 540W and 1 x 340W panels spare.

 

Where to get them in ...

 

 

What is the highest Voc voltage on any of your strings?

Do you keep the Vmp right under the 425 max?

[lom]

17 minutes ago, Muhendis said:

Would be good but don't forget that the amount of energy Crossy's potentially harvesting is not constant all day. The power output is quoted as 28.8kWp which only happens when the suns light  is perpendicular to the panels. But by any standards that's a lot of power.

I compared his April numbers to mine and I had 1500KWh from solar and  55KWh from PEA. My panels output are half of his ie 14.4KWp and my batteries are fullly charged just after midday. I don't know what to do with the sunshine in the afternoon, guess I have to get an EV soon..😃

 

[lom]

26 minutes ago, Muhendis said:

But by any standards that's a lot of power.

Do you think it might might be a world record? 

I tell ya, the guy is a living power plant..

[Crossy]

34 minutes ago, ExpatOilWorker said:

What is the highest Voc voltage on any of your strings?

Do you keep the Vmp right under the 425 max?

 

Panels are 340W, Voc = 46.3V, Vmp = 38.7V

 

Longest strings (2) are 10 panels so Voc = 463V, inverter spec. is 500V max. In reality they never get anywhere near that even on a "cool" morning.

Vmp of these strings is 387V, the MPPT range is 150-425 (max power is 300-425), but once again they tend to run well below that.

 

Snapshot just now, nowhere near max power generation this late in the day, trees and house get in the way 😞 

 

 

[Crossy]

This is the voltage of one of the long strings on startup in the morning.

 

You can see the MPPT trying to start as the voltage rises but with no power available, max voltage is about 424V then it actually manages to start making power and pulls the voltage down to 260-270V which is the max-power point at this time.

 

It's this time of day where the greatest risk to the MPPT maximum input voltage occurs. This is a major issue for those in the "cooler" parts of the world as Voc rises by about 0.4% per degree C below 25C (where it is specified). Even in Thailand a chilly, 15C, morning would raise Voc by 4%.

 

[ExpatOilWorker]

2 hours ago, Crossy said:

This is the voltage of one of the long strings on startup in the morning.

 

You can see the MPPT trying to start as the voltage rises but with no power available, max voltage is about 424V then it actually manages to start making power and pulls the voltage down to 260-270V which is the max-power point at this time.

 

It's this time of day where the greatest risk to the MPPT maximum input voltage occurs. This is a major issue for those in the "cooler" parts of the world as Voc rises by about 0.4% per degree C below 25C (where it is specified). Even in Thailand a chilly, 15C, morning would raise Voc by 4%.

 

Very interesting. One of the installers I approached, offered 10 panels per string, which would give:

Voc= 538 V (STC) 511 V (NOCT)

Vmp= 445 V (STC) 423 V (NOCT)

 

Same inverter limitations as yours, 500 V and 150-425 V.

 

His reasoning was that NOCT numbers are real world max and Voc will in practice never exceed 500 V.

 

Bit risky, so better play it safe and go for 9 panels per string. I am in the south, so low temperatures is not an issue.

[Crossy]

Why not set up the mountings for 10 panels but install 9?

 

Then if you are confident you can just slide in another panel in future.

 

I'm sure we would be OK with 11 panel strings of our lower Voc panels, But there's nowhere to put them anyway. 

[ExpatOilWorker]

7 minutes ago, Crossy said:

Why not set up the mountings for 10 panels but install 9?

 

Then if you are confident you can just slide in another panel in future.

 

I'm sure we would be OK with 11 panel strings of our lower Voc panels, But there's nowhere to put them anyway. 

Actually,  that is a very good idea.

I could even install the 10th panel and just leave it redundant, just in case one of the other 9 panels underperform or crack.