Got permission from my wife

So I purchased our first solar power kit. It's a 60W, 12V system. It includes a charge regulator and an inverter (200W). I bought it for the purpose of gaining some experience with the technology...and for showing my wife how a system worked.
Now, I need to buy a battery.
Anyhow, we have a small greenhouse....so I hope to install it on top of the roof for the purpose of powering the ventilation fan.
Regards,
Chuck