4.5 watts is equal to the power of about 4 AA 1.4 volt sized batteries. Not much power to work with.

Watts = Amps x Volts

Let's say that you wanted to run a 120 volt coffee maker that draws 2 amps when turned on.

2 x 120 = 240

You will need at least a 240 watt solor panel that is capable of producing 120 volts to run your coffee maker. You will need a huge bank of 4.5 watt solor panels to pull that off. And still you will need an inverter.

Now an inverter in it's self is a different story. It connects to a 12 volt car battery and converts 12 volt DC to 120 or even 240 volt AC.

If you choose the inverter route. Make sure that you get one large enough to power your devices. I just posted the pic and link from the first site that I came upon to give you an idea. Shop around and look at the Watts Peak Power (Like for starting a motor) and Watts Continuous Power (power it take to keep the motor running). I personally would not suggest anything under 1200 to 1500 watts continuous power when chooseing an inverter.

Here is a link that might be useful: 12V DC to AC 1400 Watt Power Inverter