how to connect the pv panel and what is the size ?

Amna, I am still not sure we have enough information... But I will give it a shot to show you how we size a system (paper designs are cheap--Do a few of them before you pay hard earned monies for your hardware).

Say you want to run 2x pumps @ 300 Watts each, for 5 hours per day. Using our typical rules of thumb for a reasonable cost effective and reliable off grid power system (full time off grid), the system may look like this--Assuming 2 days of battery storage (no sun) and 50% maximum battery discharge (for longer battery life). Guessing a minimum of 24 VDC battery bus, flooded cell lead acid batteries (cheap(er) and fairly easy to monitor and forgiving):

• 2x 300 Watt pumps * 5 hours per day = 3,000 Watt*Hours per day (enough to run a small/very efficient off grid home)
• 3,000 WH per day * 1/0.85 AC inverter eff * 1/24 volts * 2 days of storage * 1/0.50 maximum discharge = 588 AH @ 24 volt battery bank

That would be (one example) 4x 6 volt @ 200 AH "golf cart" batteries in series (for 25 volts) and 3 parallel strings (for 600 AH @ 24 volt battery bank). Or 12 golf cart type batteries. It is good to start with less expensive batteries as many of us have "killed" our first battery bank pretty quickly (mistakes, not paying attention, etc.).

Now to charge the battery bank, we do two calculations. One sizing the array to give 5% to 13% or so rate of charge. The other based on hours of sun per day for your region and your daily loads. First, sizing for charging.

5% is good for a weekend/summer seasonal system. 10%+ rate of charge is better for full time off grid system:

• 600 AH battery bank * 29 volts charging * 1/0.77 panels+charge controller deratings * 0.05 rate of charge = 1,130 Watt array minimum
  
• 600 AH battery bank * 29 volts charging * 1/0.77 panels+charge controller deratings * 0.10 rate of charge = 2,250 Watt array nominal
  
• 600 AH battery bank * 29 volts charging * 1/0.77 panels+charge controller deratings * 0.13 rate of charge = 2,938 Watt array "typical cost effective maximum" array

And then there is sizing the array based on hours of sun by day (seasonal) and the location of the system. Lets use a fixed array in Sharjah, UAE:
http://www.solarelectricityhandbook.com/solar-irradiance.html

Sharjah
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 65° angle from vertial:
(For best year-round performance)

Jan	Feb	Mar	Apr	May	Jun
5.16	5.99	5.80	6.37	6.67	6.54
Jul	Aug	Sep	Oct	Nov	Dec
5.98	6.15	6.44	6.61	5.84	4.93

A very sunny region of the world, assume you need water pumping pretty much all year round (maybe you can cut back by 30-40% in "winter" months--Pick December with 4.93 hours of sun for "break even" month (cut back on pumping or start a generator in bad weather):

• 3,000 WH per day * 1/0.52 off grid end to end system eff * 1/4.93 hours of sun (Dec) = 1,170 Watt array minimum (Dec)
  

So, somewhere between a 1,170 Watt and a 2,250 Watt array should do nicely.

A 24 volt @ 600 AH flooded cell lead acid battery bank will run a 1,500-3,000 Watt 24 volt AC inverter pretty nicely. I would suggest you keep the AC inverter only big enough to run your loads (start your pumps). Too large of AC inverter will waste energy just being turned on (no AC loads)... Ideally, you would only want the inverter to run with the pumps are needed--A larger inverter can draw (waste) 20-40+ watts just being turned on with no loads (tare loading).

Anyway--A quick paper design. Just a starting point. Please feel free to ask questions and correct my guesses.

Note that there are other ways of pumping water... A common method is to get a DC compatible water pump that can connect directly to a solar array. It will only pump water during the day (if that is good enough for you)--Pump to a cistern/storage pond, etc. Solar Powered DC pump motors are not cheap--But saving the costs and maintenance of battery bank+AC inverter+checking that all is OK/adding water--Solar only pumping can be a huge improvement over battery based AC pumping.

-Bill