several questions

[amit5674]

Hi,
1. The solar charge controller is in VDC and the solar output power is in watt. so in case I have solar charger with min Solar Voltage of 120VDC how can I know the minimum watt the solar panel should generates? I want to buy 1 panel of 100W. the solar charger will operate?
2. what is the key difference between Micro-Inverter and DC power optimizer? in which circumstances I should prefer one instead the other? which is the most suitable for off-grid system?
3. what is buck-boost converter structure? what its advantages?
4. what is bypass diodes mechanism from Hot-Spot prevention?
Thanks

 

[upnorthandpersonal]

1: everything is power: power in == power out. You will not find a 100W panel that can output 120VDC: look at the panel specifications, it will tell you a power output (Watt), a Maximum Power Voltage (Vmp) and Maximum Power Current (Imp). Multiplication of those latter two will give you the Power. You now have to match a set of panels to comply with what your charge controller needs at the input, and the power requirements you need at the charge controller output.

2: none. micro-inverters are for grid-tied systems (generalized). DC optimizers are a waste of money in most cases.

3: For what purpose?

4: bypass diodes make it so that strings of solar cells get bypassed through a diode in case of shading. These are built in into all modern solar panels.

 

[Rednecktek]

Hi,
1. The solar charge controller is in VDC and the solar output power is in watt. so in case I have solar charger with min Solar Voltage of 120VDC how can I know the minimum watt the solar panel should generates? I want to buy 1 panel of 100W. the solar charger will operate?

Nope, your 100w panel is only going to produce about 18-20v or so, you'd have to series at least 11 of those together to reach minimum voltages.

2. what is the key difference between Micro-Inverter and DC power optimizer? in which circumstances I should prefer one instead the other? which is the most suitable for off-grid system?

The microinverter is for grid-tie so completely useless and the optimizers are a waste of money as what little performance gain you might get out of them would never break even for having to put one on every panel.

3. what is buck-boost converter structure? what its advantages?

Converters are for changing voltages on DC systems. It is used in cases where you run a 48v based system but need to power a 12v heater or the like. It just converts the voltage down.

4. what is bypass diodes mechanism from Hot-Spot prevention?

Bypass diodes are to help a panel deal with shading without nerfing an entire string and really have nothing to do with hot spots.

Thanks

We're here to help!

 

[mpgmike]

Buck/Boost refers to what the DC-DC converter is doing; Buck is taking a higher DC voltage and stepping it down to a lower DC voltage -- like going from 48 to 12 volts. Boost is the opposite; it takes a lower DC voltage and steps it up to a higher DC voltage. The Buck/Boost strategies when applied to a charge controller means that when your 48 volt panels are cranking out over 60 volts in direct sunlight, the Buck function steps it down to your 48 volts. In low-light conditions, there is still energy coming from the panels, but maybe only 30 volts. The Boost function can actually take that 30 volts and bump it up to your 48 volts, allowing you to keep charging the batteries (or powering a load).