Until you add in the cost of gas... especially after a hurricane.
I've done extensive research on solar power myself, the cost/benefit is just not there unless you plan to spend 10 years on grid power or 100 days without. 1800w will run a small refrigerator | TV and lights | Small microwave | Hair dryer | Small water pump. HOWEVER! You will need a huge battery pack to maintain any such usage for more than incredibly short intervals. One minute with a | Small microwave | will burn 30 watts of power per minute or 1800 watts per hour. That 30 watts will take your 90 watt panel a *minimum* 1 hour to replenish unless you are in the middle of the Sahara. Your average deep cycle 12v battery can supply ~300-400 watts of power for an hour before running too low. Your battery packs only last 3-4 years tops before they require replacement, providing they don't get overcharged or discharged sooner, which is an expensive job. Basically your solar panel duty cycle is incredibly short and can only be used for emergency power. The time required to replace used power is too great and available power is too small. You are just as good off buying a power inverter for your car/truck and using it as an emergency power source. Not only that, you can take it with you when the zombies invade.Until you add in the cost of gas... especially after a hurricane.
I was out of power for 29 days after Katrina, 5500Watt gen caost me $700 to keep the referator & freezer, water well and some lights & fans going but not continously. Later I added a small A/C to the mix. Heated water on the propane stove to wash clothes & stuff by hand.