Battery bank for a 12kw solar system

[Beanyboy57]

Update.

The 10kw system has now been running without a hitch for a few months producing an average of 40kw/h per day. We are charged at 42 cents per unit (kw/h) by our provider and they will give us 48 cents per unit that we provide to the local generator powered grid.

[solar pete]

The 10kw system has now been running without a hitch for a few months producing an average of 40kw/h per day. We are charged at 42 cents per unit (kw/h) by our provider and they will give us 48 cents per unit that we provide to the local generator powered grid.

G'Day Beanyboy57 thanks for poppin in and giving us an update, good onya mate.

[SunEagle]

The 10kw system has now been running without a hitch for a few months producing an average of 40kw/h per day. We are charged at 42 cents per unit (kw/h) by our provider and they will give us 48 cents per unit that we provide to the local generator powered grid.

Congratulations on your system. Seems like a great deal to be able to sell your power for more than what your POCO charges you.

[inetdog]

The 10kw system has now been running without a hitch for a few months producing an average of 40kw/h per day. We are charged at 42 cents per unit (kw/h) by our provider and they will give us 48 cents per unit that we provide to the local generator powered grid.

That's kWh, not kW/h. Watts are already a time rate of energy flow. Makes a difference when you try to run the numbers.

And congratulations!

[Beanyboy57]

That's kWh, not kW/h. Watts are already a time rate of energy flow. Makes a difference when you try to run the numbers.

And congratulations!

Thanks for the clarification. We are looking forward to the first power bill from Horizon Power Co. Hopefully we will have a reduction. My calculations gave me a rough estimation of a 14% reduction of overall costs in a 12 month period.

[PNjunction]

Awesome - although I may be nitpicking about safety..

I see what looks like exposed terminals about. Do not drop a wrench, metallic folding chair etc across those. Sounds obvious, but just kinda stands out to me.

AND, if you or a person trained and qualified to be near such equipment, I'd want to check the voltages of what appear to be four agm batteries sitting on the floor. What we are looking for is unequal voltages indicating a loss of balance and/or poor charging or high-resistance contacts. It looks good now, but a year from now when connections expand / contract?

Maybe add a handheld IR thermometer to your toolbench so you can point it around to see if any area on the battery or cabling gets much hotter than the rest. If you keep track of stuff on a regular basis now, you may be able to fend off a problem that goes major down the road or at least call in the maintainers to jump on it...

[Beanyboy57]

Awesome - although I may be nitpicking about safety..

Maybe add a handheld IR thermometer to your toolbench so you can point it around to see if any area on the battery or cabling gets much hotter than the rest. If you keep track of stuff on a regular basis now, you may be able to fend off a problem that goes major down the road or at least call in the maintainers to jump on it...

I'll take that on board. Would any well know brand of IR thermometer suffice?

[SunEagle]

I'll take that on board. Would any well know brand of IR thermometer suffice?

FLIR and Fluke make very good IR cameras. The costs have come way down and they provide the user a colored thermal image which will pick up "hot" spots better than one that just shows you an average temperature reading.

[Beanyboy57]

Update: Spring is here.

With a yearly average insolation factor of 5.7, what is the average daily output I could expect from my 10kw system? The average amount of bright sunshine hours according to the Australian Bureau of Meterology is around 8 for this region. I am guessing 5.7 is when the sun is between two set angles from sunup (between 45 and 135 maybe) to sundown?

Now that spring is here and the days are sunny, the skies are clear, the array is producing an average of 70kwh each day.
Average daily maximum temp is around 22c but will soon jump to around 30c for October and then around 37 for December through to the end of March.
I am guess that the daily output will reduce over the hotter seasons. Am I correct?

Should I be pleased with this system or should it be more efficient?

[azdave]

I am guess that the daily output will reduce over the hotter seasons.

No guessing required...you will see reduced output in the heat.

Panel specifications even tell you how sensitive they are to heat so you can predict the output reduction. My 6.6kW system is in the desert in Arizona and even with the days being shorter in the spring and fall I see better production at those times than in the summer, mostly due to lower air temps. In June we have the most daylight hours but the high temperatures knocks down the production. In the spring and fall I can have some days in the 44-45kWh range but in the worst summer heat 35-38kWh is usual.

[lkruper]

FLIR and Fluke make very good IR cameras. The costs have come way down and they provide the user a colored thermal image which will pick up "hot" spots better than one that just shows you an average temperature reading.

I have an IR (spot) thermometer, but never heard of those devices. Sounds like it would also be useful to see where heat is leaking from a house as well.

### Ouch! ###
$1500

http://www.amazon.com/Fluke-FLK-Ti90-80x60-Infrared-Camera/dp/B00JJQ3SNW

###

[SunEagle]

I have an IR (spot) thermometer, but never heard of those devices. Sounds like it would also be useful to see where heat is leaking from a house as well.

### Ouch! ###
$1500

http://www.amazon.com/Fluke-FLK-Ti90-80x60-Infrared-Camera/dp/B00JJQ3SNW

###

Both FLIR and Fluke now make a pretty simple versions of their IR camera for less than $1000. It all depends on how much detail and accuracy you need.

The difference between the camera and spot meter is one you get a "heat energy" picture of the object showing hot and cold points. The spot meter will only provide the average temperature within the "target circle". If that circle is too big you end up including temperature points that can bring down the average and provide you a false number of the actual target.

[Willy T]

You can buy one that fits onto a Iphone for $150 or so.

[SunEagle]

You can buy one that fits onto a Iphone for $150 or so.

Yeah. I have seen that IR attachment for an Iphone. I'm not sure how the quality of the phones camera compares to a hand held IR camera but it might be good enough.

[Beanyboy57]

With a yearly average insolation factor of 5.7, what is the average daily output I could expect from my 10kw system? The average amount of bright sunshine hours according to the Australian Bureau of Meterology is around 8 for this region. I am guessing 5.7 is when the sun is between two set angles from sunup (between 45 and 135 maybe) to sundown?

Now that spring is here and the days are sunny, the skies are clear, the array is producing an average of 70kwh each day.
Average daily maximum temp is around 22c but will soon jump to around 30c for October and then around 37 for December through to the end of March.
I am guess that the daily output will reduce over the hotter seasons. Am I correct?

Should I be pleased with this system or should it be more efficient?

I forgot to add that the system is now fully built and is just over 13kw.