If you want to have reliable power in the case of a black-out, you need some kind of back-up system. If you already have solar panels in a grid-tie set-up, or if you are planning to have them installed, the best way of storing your excess power is a bank of deep-cycle batteries.
Grid-tie systems without back-up storage will not provide power to your home when the grid fails. Their only function is to reduce your power bill by feeding power to the grid. In a blackout they will be sitting idle on your roof, and you will be without power.
The obvious solution is a battery bank. Kept fully charged while-ever the grid is up, your battery back switches in when the grid fails. During the blackout, the batteries power your home while being charged from your solar array. You will never be totally without power.
The battery back gives you many options. If the outage is extensive and your solar panels don’t provide all the power your home needs, you can recharge from a portable gas-powered generator, a wind generator or a micro-hydro generator.
The disadvantage of battery-backup for your grid-tie system is the cost of the batteries. Deep-cycle batteries are expensive and their life-span is limited. However, if you want to achieve any degree of energy independence, this is the best option currently available. Battery technology is improving all the time, and the hybrid system is the way of the future. If the grid fails totally and for an extended period, you will continue to have reliable power. If grid power becomes too expensive, you will have the option of going totally off-grid.