System Performance Issues - Help!

[djmitzlplick]

I have a VERY unusual system.

My PV system provides power for the living space of my 40' schoolie RV, and has been working well for 7 years. I have been developing a self-contained Closed Ecological Life Support System for Total Off-grid living - 1) produce power, 2) recycle water, 3) recycle wastes, 4) produce food on-board.

20 panels rated around 40v and 300w for array max of 6kw. They are arranged in 5 strings to group similar outputs. Panels are 7-10 years old.

These feed a (2 yr-old) 5kw charge controller/inverter unit that keeps my 24-6v batteries charged and provides on-going power.

This year I rebuilt my roof deck and realized I could move ALL panels to the sides, and be able to use the full deck.

Installation went well, and I expected to see a min of 3kw output at peak sun. I've been struggling to get more than 1.5 kw at peak, and it's very frustrating!

Additional notes:
50' pine shades driver side (due east) panels till 9am
All panels in full sun by 10 am till 3-4pm, then driver side shadowed till sunset.

There are 10 panels on each side angled about 45°, that SHOULD produce over 2.4kw per side. My batteries have not gotten above 30% in weeks.

I have verified the connections, and 35-40v output at each panel.

Looking for suggestions to get back to full power!

 

[DougfromdaUP]

So are the panels facing east and west, and tilted up 45 degrees, or are they actually facing the sun?

 

[djmitzlplick]

East and west tilted up.

 

[outsider]

I am consulted with a professional solar installer about solarizing my home (Heresy!) and he advised me that compared to panels on a slanted roof I have that faces south, panels on a similarly slanted roof but facing east would produce about 1/4 of the total energy, and likewise for panels slanted but facing west. Is there some way you could rotate each panel such that they come closer to facing the sun at noon but without shading each other?

 

[Mkgough]

I have a VERY unusual system.

My PV system provides power for the living space of my 40' schoolie RV, and has been working well for 7 years. I have been developing a self-contained Closed Ecological Life Support System for Total Off-grid living - 1) produce power, 2) recycle water, 3) recycle wastes, 4) produce food on-board.

20 panels rated around 40v and 300w for array max of 6kw. They are arranged in 5 strings to group similar outputs. Panels are 7-10 years old.

These feed a (2 yr-old) 5kw charge controller/inverter unit that keeps my 24-6v batteries charged and provides on-going power.

This year I rebuilt my roof deck and realized I could move ALL panels to the sides, and be able to use the full deck.

Installation went well, and I expected to see a min of 3kw output at peak sun. I've been struggling to get more than 1.5 kw at peak, and it's very frustrating!

Additional notes:
50' pine shades driver side (due east) panels till 9am
All panels in full sun by 10 am till 3-4pm, then driver side shadowed till sunset.

There are 10 panels on each side angled about 45°, that SHOULD produce over 2.4kw per side. My batteries have not gotten above 30% in weeks.

I have verified the connections, and 35-40v output at each panel.

Looking for suggestions to get back to full power!

Did you test each panel for a failing panel?

 

[djmitzlplick]

I tested all panels, they are putting out 30-40 volts each.

 

[SolarFlares]

Did you verify the current at each panel as well? The power is either not being produced due to the change in location/orientation OR there is wiring issue somewhere. Try using a clamp style meter to validate each panel, then each string all the way to the charge controller/inverter.

 

[djmitzlplick]

Did you verify the current at each panel as well? The power is either not being produced due to the change in location/orientation OR there is wiring issue somewhere. Try using a clamp style meter to validate each panel, then each string all the way to the charge controller/inverter.

Been thinking in watts for so long, forgot about amprobe. will check it out in the morning.

 

[DougfromdaUP]

What does PVWatts, or any other modeling software say you should expect the panels to produce in that orientation?

 

[rustythorn]

I have a VERY unusual system.

My PV system provides power for the living space of my 40' schoolie RV, and has been working well for 7 years. I have been developing a self-contained Closed Ecological Life Support System for Total Off-grid living - 1) produce power, 2) recycle water, 3) recycle wastes, 4) produce food on-board.

20 panels rated around 40v and 300w for array max of 6kw. They are arranged in 5 strings to group similar outputs. Panels are 7-10 years old.

These feed a (2 yr-old) 5kw charge controller/inverter unit that keeps my 24-6v batteries charged and provides on-going power.

This year I rebuilt my roof deck and realized I could move ALL panels to the sides, and be able to use the full deck.

Installation went well, and I expected to see a min of 3kw output at peak sun. I've been struggling to get more than 1.5 kw at peak, and it's very frustrating!

Additional notes:
50' pine shades driver side (due east) panels till 9am
All panels in full sun by 10 am till 3-4pm, then driver side shadowed till sunset.

There are 10 panels on each side angled about 45°, that SHOULD produce over 2.4kw per side. My batteries have not gotten above 30% in weeks.

I have verified the connections, and 35-40v output at each panel.

Looking for suggestions to get back to full power!

you might want to throw in some pics to help explain your setup. as a side note, i've toyed with a similar concept [ie a large RV with a self contained eco system [eg vegetables, fish, chickens, etc...]]. instead of calling it a terrarium i was going to call it a TREKARIUM

 

[HarryN]

Sounds very interesting. Probably you will need a clamp meter to figure it out. They measure the current flow in each wire.

There are a number of options on the market and I am not an expert, but own some of these = actually the prior models:

This one is good for DC currents that are not very large ( up to 80 amps ) but it's big strength is the ability to get into tight places to put around wires. Really good for solar related.

EXTECH 380950 80A Mini AC/DC Clamp Meter

EXTECH 380950 80A Mini AC/DC Clamp Meter has small diameter elongated jaw to fit into tight spaces. 4000 count LCD display. 1mA resolution. Jaw opens to 0.5 (12.7mm). AC/DC Voltage, Resistance, Frequency, Capacitance, and Duty Cycle. Diode Test/Continuity Beeper. Data Hold. Complete with test...

www.extech-online.com

For larger currents, such as feeding the inverter, then something with a range up to 400 amps can be helpful, such as this:

EXTECH 380947 400A True RMS AC/DC Mini Clamp Meter

EXTECH 380947 400A True RMS AC/DC Mini Clamp Meter is a True RMS mini-clamp meter with high current resolution. 0.9 (23mm) jaw opening. True RMS measurements with 1mA AC resolution. Non-contact Frequency measurements to 10kHz through the clamp jaws. Fast 40 segment bargraph. One touch Auto Zero...

www.extech-online.com

____________

At the end of the day, most challenges with off grid power system are due to crimps. Everyone wishes that the connections that they make with a $100 crimper are good, but most aren't.

Photos will definitely help us help you.

 

[robinsharma]

How can we increase the efficiency of this system?