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Use of solar panel for power inverter.

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Newbie level 5
Nov 12, 2009
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Hello house. I constructed a 5KVA Power inverter using a 24V battery source. Now I want to replace the battery with a solar panel. What is the specification of the solar panel I can use? Also, can I just connect the solar panel the same way I connected battery?

solar panels are used to charge a battery with charge controller.
the battery supplies power for inverter.

if you want to remove battery and substitute solar panel , you must make sure that a charge controller like unit that gives constant voltage should be used.

a panel without battery , is heard for the first time.
but if you are research minded then you can.

You have constructed an inverter and we do not know the current limitations of the system. What’s the maximum input voltage accepted? Is there’s a voltage stabilizer for the control circuit power supply? A solar panel give a large range of voltage at output, so the converter need to accept this.
By the other hand, not using some battery at inverter input, need to have large capacitors instead, in order to compensate some short variations of the panels power output.

It's quite normal to operate solar panels with inverters without a battery. Solar energy harvesting with grid connected inverters is using this scheme.

But the operation mode is different. In energy harvesting, the solar panel is operating at the maximum power point and the inverter will supply all available power to the grid, whatever it is.

A stand-alone inverter has to obey this restrictions:
- the power supplied to the load can't be larger than the present solar panel output (minus conversion losses).
- the inverter must be either capable of processing the maximum open cicruit voltage of the solar panel, or must have a means to dissipate excessive input power.
Most people will prefer to combine the solar panel with an energy storage battery for this reason, if used with a stand-alone inverter.

eventhough an efficient MPPT circuitry in place without battery the inverter maybe less efiicient.....

Why? You won't find batteries in solar energy harvesting plants, but they are operating with high efficiency though.

I have several years' experience with 8 photovoltaic panels, a 2500W inverter, and a 24V battery bank made from 8 golf cart batteries.

Manufacturers rate solar PV panels at the highest watts they'll put out.

The ones I used were rated 64W. One would deliver 3 or 4 amps into a 12V battery.

Open circuit voltage was 23 V. That's with no load. Voltage would drop to varying degrees depending on what load was attached.

I tested a panel with various loads. The greatest power output occurred with a 6 ohm load. Then voltage was about 16. Current flow 2.7 A.

As a rough estimate, to power a 5000 W inverter at 24V input, you'll need:

100 panels rated 50 W each.
or 50 panels rated 100 W each.
or 25 panels rated 200 W each. Etc.

To deliver 24 V to your inverter, you'll need setup A or B or C below:

(A) If your load is unchanging then each panel must contain the exact number of cells which you have found will stay at 24V in accord with the load it sees in your inverter. This may or may not be the same number of cells built into a typical PV panel.

Setup A is hard to live with you can't easily divide up PV panels. Changing sunlight will change PV output unpredictably. Furthermore some inverters may refuse to operate when fed greater than a certain voltage.

............ or

(B ) If your load is changing than you'll need a DC-DC converter set to provide 24 V output regardless of the voltage coming from your panels.

How many cells should go in each panel, or how many panels to string in series, depends on the specs of your converter.


(C) Use a 24V battery bank hooked up to a PV array. PV panels are strung as two panels in series, and you'll parallel sufficient strings to power your inverter.

In this case the battery serves as a voltage regulator so as to maintain 24 V at the inverter input.
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Dear All,
Need help about pulse transformers, in fact I want to drive 4 MOSFETs with an only one pulse transformer, is it possible, if yes please I need the part number of such transformer

This is bad system! This design is not good for 5KW on 24V!!!!

All system cant work longer on that current with batteries neither without them.

Except if You have batteries each 500Ah capacity or more.

Also You have steel rodes instead of wires (High amperage). At 24V voltage, that high current can start arc like at welding.
At peak or high load 5KW You have 208A current !!!!!!! :shock: This is not submarine electrically driven.

Paralleling batteries bring lots of risc and problems.

For such power system should be on at least 48V or 72V.
72V system at 5KW have 70A.
If You use 180Ah batteries (start or deep cycle very important thing!) 180Ah/10h=18A Nominal discharge current based on 10h time discharging. If You go under 10h declared capacity change then capacity is much much lower.
If You use starter batteries use float discharge maximum 30% of battery capacity or batteries go to heaven. :lol:
Deepcycle ok for deep discharge but with smaller starting current.

Theoreticaly if 18A for 180Ah 10h, and system is 24V You see point of this? How many batteries is needed?

If there is no batteries in this 24V system ok, that is not problem, but consider usage "full steel pipe" as wires to inverter.

I hope this is not close to your house, and that You have ready fire extinguishers.

Better rent this system for welding. :wink:

Better buy 5KW generator on LPG/Gasoline.
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Would anybody provide the charge panel circuit for this set-up ?

solar panels are used to charge a battery with charge controller.You should have constructed an inverter and we do not know the current limitations of the system. What’s the maximum input voltage accepted? Is there’s a voltage stabilizer for the control circuit power supply?

Nowadays, some inverters (called micro-inverters or AC module integrated) are directly mounted to the back of each photovoltaic and the battery is for the entire array.

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