Yes, definitely! They are the best solar kits on the market for a long term investment in emergency backup.
It comes down to the batteries. Nickel Iron batteries can be stored for years and brought back into service without loss of capacity. This is not true for lead acid or lithium, which are both damaged by storage.
If you want to have your back-up system ready for use immediately, keep the box connected to a PV panel in full sun. You will have to put distilled water in your batteries once per month if they are connected to a PV panel, even if they are not being used.
If you don't want to water your batteries while they are in storage, you'll have to store them dry (without electrolyte) and disconnected from the solar panel. When it's time to put them into service, you'll have to add electrolyte and connect your batteries to the panel. Discharged NiFes will take 2-3 days of sunshine to come up to full charge.
While an Iron Sun Power Supply is uniquely suitable for emergency back-up power, we don’t recommend you stick them in a closet. We recommend that you unplug yourself from the electric grid and start using our products today!