help with new system

[madmurg]

I had my 3.8kw system with sanyo panels and sma invertor fitted about a week ago. The highest output I have had on a bright sunny day is only 750w is this correct for this time of year. I am west facing and have been getting 3kw total for the day.

 

[langstroth2]

Some useful further info might help with replies:
Any shading issues?
Directly west facing/ orientation in degrees?
Approx Location?

Does sound a bit low. Looking on PV output for today: A south facing 4kw system (Southern England) achieved 6.7kwH; West facing 3.36kw (West Lothian) 897w

 

[madmurg]

I am in the midlands and I am just past west facing sorry don't know the degrees

 

[langstroth2]

What did it generate today (Tue) ?

For comparison there's a Birmingham system, East facing 3.9kw system generated 1.626kwH, peak of 627w

Today was quite sunny in the SE - my system peaked at 2004W, so if you've had some sunny days the 750W sounds way to low for a peak.

Is the array wired as two strings to the inverter (two mppt inputs) ? Some inverters will show you the output from each string - could be one string isn't connected properly (750W x 2 = 1500W which would be more like it for an OK Nov day I would think)

 

[madmurg]

It is wired as 2 strings and total peak today was 680w and generated 2.57 kwh

 

[langstroth2]

The weather and shading can have such a huge impact it's hard to know really without comparing to a within a few km nearby system.
e.g. Birmingham postcode, SW orientation, 4kw system produced 6.540kwH today, peak 1452W. Very different from the above system I quoted- and only about 45km apart.

What inverter do you have - does it display output for each string separately. If yes, it will be worth check if both strings are producing roughly the same output at any given time.

They are probably very busy - but I'd suggest going back to ask your installer if you have any concerns. A peak of 750 with sun on the panels is low.

 

[madmurg]

I have no shading at all and my inverter is a sunnyboy 3800. I get my readings from a sunnybeam as my inverter is in the loft.

 

[Gary K]

Sounds very low. My system is only .04kw larger with the same inverter and produced 10.6 kwh today in Norwich. It faces SSE but I understand facing West should only be about 20% less so that would be around 8kwh.
Assuming you can isolate the 2 strings as others have suggested, I would check the individual output of each which you can do on the SB3800 as it cycles through the differant reading.