Powering 24 volt solenoid valve with Arduino uno Today I received normally closed solenoid valve which I am going to use in automated pot watering system , 
I realised the valve takes 24 dc volt as input and Arduino has maximum of 5volt , using some power booster I can convert it to some extent but I think 24 volt is too much .

So how should power 24volt solenoid valve from Arduino uno?
Since the solenoid requires higher current than the arduino can provide you can use an alternative power source for the solenoid (maybe a couple of batteries) and switch it with a TIP120 transistor.