I am looking to work an Arduino in tandem with a solar panels and a battery to operate a water pump.
Any suggestions on the best Arduino product for this job?
Also, I need to figure out how many solar panels I need as well as what size battery. Any suggestions on what to look for when integrating electronics would be great. Thanks so much.
Of what? The Arduino? The solar panel? The pump? Details matter!
No Arduino will read AC voltages without external hardware and processing. No Arduino will drive 120V AC equipment without external hardware.
Also, I need to figure out how many solar panels I need
Calculate the area where the solar panels will go. Calculate the area of one solar panel. Divide the first number by the second number to get the number of panels that will fit.
If you need some other method of figuring out that value, based on no data, roll some dice.
How much current can one panel output? How much do you need?
as well as what size battery.
In Arizona? Or Seattle? I'd recommend one 18" by 14" by 12".
If you are talking about a pump with an AC motor I strongly suggest that you look for a pump with a DC motor - preferably 12v or 24v.
Your solar panel will produce DC and the batteries that store it will be DC. Converting to AC will be inefficient.
As far as the size of your solar panel is concerned you will have to calculate (or estimate) how many amp-hrs at the battery voltage the pump will require every day. Do not under any circumstances make an under-estimate.
Then you need to figure out how much solar energy is available in the worst case (cloudy short winter days) and size yout panels so that on average they supply at least 50% more than is needed - to allow for battery and other inefficiencies.
If you don't need the pump to run at night that will simplify matters. But you will probably need to size the batteries so that they can keep the system working for a few days with very little sunshine. How long depends on your local climate. Assuming you use lead-acid batteries you must design the system so that they do not remain discharged for long.
This JRC website may be useful.
Compared to the pump I suspect the Arduino's energy requirement will be trivial.