Solar Charge Controllers - Multiples

[Sunking]

No. In engineering terms, all MPPT controllers are "buck" converters - they reduce output voltage while increasing current. They do not boost voltage.

That is mostly true but there are a few high end manufactures like Mid Night Solar that have buck/boost built into 1 controller. The Boost range is very limited, and when operated in Boost are very inefficient. So i would never recommend anyone operate in a boost range. For a 48 volt battery your minimum panel Vmp should be 62 volts. This will be the point where most quality MPPT controllers are most efficient on a 48 volt battery system.

[billvon]

That is mostly true but there are a few high end manufactures like Mid Night Solar that have buck/boost built into 1 controller. The Boost range is very limited, and when operated in Boost are very inefficient. So i would never recommend anyone operate in a boost range. For a 48 volt battery your minimum panel Vmp should be 62 volts. This will be the point where most quality MPPT controllers are most efficient on a 48 volt battery system.

That would be great; a boost mode would help a lot when using odd-sized panels (i.e. 48/96 cell panels) on off-grid systems. The last Classic manual I saw had this note:

"Boost Charge Mode (Lower to Higher Voltage, Unimple-mented as of May 2011)"

Have they since implemented this?

[Sunking]

That would be great; a boost mode would help a lot when using odd-sized panels (i.e. 48/96 cell panels) on off-grid systems. The last Classic manual I saw had this note:

"Boost Charge Mode (Lower to Higher Voltage, Unimple-mented as of May 2011)"

Have they since implemented this?

I believe so. They make them right here in TX and i have a couple of sample units to play with. Honestly I have not tried them in Boost Mode as it is not something I would ever implement becuase of the efficiency issue. Besides the Boost range is very small, something on the order of 50 volts on a 48 volt battery system. I am not willing to go there.

[solarponders]

Hi All

For my solar system, I am a bit confused about the terminologies used for inverters ... (off-grid, grid-tie)

In where am located, (India) selling back the power to grid is not an option ..

So I am looking for an inverter which serves dual purpose :

1) Converting DC to Ac to supply power to my house
2) Converting Power Supply AC to DC to charge my batteries. That is batteries could get charged both from PV and/or Power Supply.
I believe every inverter is equipped with a rectifier/charger to do this.

And, more importantly - I would like an auto-switch over from the Battery to Power/Mains when Battery is Low and
from Mains to Battery when power supply is cut (there are huge power cuts in our zone). Precedence to be given to battery
power, if available. Can such setup be possible?

Thanks in anticipation!!

[Mike90250]

...
My mppt vendor tells me there is a tweak that can be done to set the battery
input voltage to 24v and output to 48v. Does that make sense? Not to me, at least.

not to me either. If your vendor cannot show you a system working as he described, I bet it does not exist. Sorry.

To run a 48 v inverter, you need 48V

You would need a new charge controller at the very least, and a 48V battery bank of course.


To interact with the grid, I know the XW series of inverters will do that, and I think Outback has a model that can also.

The xw-6048 that I have, has the transfer relays built in, and a grid AC input/output (it has a No Sell mode) and a 2nd AC input for a 240VAC generator . And an internal battery charger.

[billvon]

So I am looking for an inverter which serves dual purpose :

1) Converting DC to Ac to supply power to my house
2) Converting Power Supply AC to DC to charge my batteries. That is batteries could get charged both from PV and/or Power Supply.
I believe every inverter is equipped with a rectifier/charger to do this.

These certainly exist but not every inverter does this. You need an inverter/charger. For example the Prosine 1800 does not have a charger but the Prosine 2.0 does.

And, more importantly - I would like an auto-switch over from the Battery to Power/Mains when Battery is Low and
from Mains to Battery when power supply is cut (there are huge power cuts in our zone). Precedence to be given to battery
power, if available.

Yes. The old Trace SW series did this. I THINK the Outback series of inverters will do this as well.

However, this is not the best use of batteries. If you have a grid and can do grid intertie it is much better to run off the grid and reserve your batteries for backup power. One, they will last a lot longer. Two, if you are always discharging your batteries they will be dead when you need them.

[solarponders]

Does anyone have experience with thin film solar panels? I ran into one resller, where the cost quoted
per watt of the panel is 2/3rd of the regular (mono/poly) .. here is the product data sheet.

http://www.nanosolar.com/sites/defau...NSC-001_12.pdf

Not sure, if this is a new breakthrough in the technology (by German) that has brought a significant drop in the
panel price or just an experimental thingy ...

[Sunking]

Does anyone have experience with thin film solar panels?

Yes runaway, do not walk. They are like DIY panels and will be useless in 5 years or less.

[russ]

Yes runaway, do not walk. They are like DIY panels and will be useless in 5 years or less.

Nano Solar - Aren't they one who has been promising the world and delivered very little or nothing for years now -

[BritishPete]

Does anyone have experience with thin film solar panels? I ran into one resller, where the cost quoted
per watt of the panel is 2/3rd of the regular (mono/poly) .. here is the product data sheet.

http://www.nanosolar.com/sites/defau...NSC-001_12.pdf

Not sure, if this is a new breakthrough in the technology (by German) that has brought a significant drop in the
panel price or just an experimental thingy ...

I can't give you advice for the present sales but below is a link to information new to the market today and pretty amazing I think;


http://cleantechnica.com/2012/03/14/...eanTechnica%29

Hope the link works it's long !