determining power sources for a simple dc motor.

I am currently doing a project on remote device for opening a high level window. I have to evaluate 3 power sources for driving the simple dc motor. The motor operates at a voltage of 15v and has a max discharging current of 0.837A, the motor also has an efficiency of 61.85%. The full specification of the motor is shown below.
I am looking to power tis motor by either photoelectric cells, rechargeable batteries or mains electricity.

My first question would be how do i device a circuit which can power this by the mains, ie how do i know the current and voltages required by motor will be met.

My second question again is how to determine how the voltages and current are meet when using rechargeble batteries. For example if I have the following 3 batteries:
battery 1: 9V 170mAh
battery 2: 1.2V 1100mAh
battery 3: 1.2V 550mAh

finally I cannot find out to much about purchasing photoelectric cells. The only information on the photoelectric cell I found was that it had a power rating of 1.8W.
Again my question is how many of these cells would b required if it can power the motor.


Any information would be very much appreciated, I am really stuck on this and find it slighlty confusing. I look forward to hearing from you.

Thanks
Conor

A 15 Volt, 12.55 Watt motor should be driven by rechargeable batteries.
Let's assume the batteries must be able to drive the motor 15 minutes.

Step 1. Required Voltage
One cell has a nominal voltage of 1.2 V. So we need 13 cells in series.
1.2*13=15.6V

Step 2. Required Current
12.5 Watt at 15 V requires a current of 0.837 A.

Step 3. Required Capacity
The required battery capacity is 0.837A during 15 minutes = 0.210 Ah = 210 mAh.

Step 4. Allowed Current
Assume the maximum current for the batteries is 3C, that is 3*210 mA = 0.63 A. This is less than the continuous motor current.

Step 5. Start and stall conditions
At start, this motor may cause a current of 5 times the nominal current, that is 4.185 A.
If 3C is the maximum current, a battery is required with a capacity of 4.185/3 = 1.395 Ah.
If other types like high drain batteries (10C) are applied, their capacity should be 4.135/10 = 413 mAh.



Conclusion
You need to take care about the inrush current at startup of motors (about five to eight. times the nominal motor current) , and is usually not an issue for big power supplies but for low capacity accumulators may be a problem. The 1100mAh battery it's on limit for the current required for that motor. So, if the motor use a 15V power supply, you will need to combine 15V/1.2V= 12-13 elements. If the motor will be frequently switched on and off you should consider using larger capacity batteries.