Going off grid has never been more possible than it is today! If achieving self-sustainability is your goal in going solar, there are a few things to keep in mind.
A completely off grid system is one that generates power, stores that power in batteries and runs completely off those batteries. These systems are not tied to the electrical grid. This is a great option for any customer that wants to be completely self-sufficient.
Costs
The cost of an off grid system varies drastically, depending on the size, application and components used. One of the main components that is added in these systems is the solar battery. Of average, these can cost $5,000-$20,000. Depending on the size of the system and your energy usage, more than one battery may be necessary.
The Tesla Powerwall, for example, costs $8,500 before installation costs. This battery has a 13.5 kWh capacity, roughly half of what an average home uses in a day. 2-3 of these would be needed to ensure the home has the proper energy bank available, and this would make the total cost for just the batteries between $17,000 and $25,000.
It's a costly investment to go off grid, but with rising costs of electricity, fuel and other commodities, this kind of system would ensure that you have a predictable bill for your energy for the foreseeable future.
How It Works
There are times when your panels will be producing an abundance of power. In an off grid system, this abundance would be stored on your batteries so that you can utilize the energy when the panels are producing less (on a cloudy day, etc.). All power going to your home will rely completely upon the power being produced or the power stored in your batteries.
In a grid tied system, most customers opt for the net metering option for excess power. Basically, anything you produce that is over what you are using goes back to the power company. The power company then converts this to energy credits that are applied to your monthly bill. Unless there is a power outage, grid tied systems will always have access to the power grid, so if the panels aren't producing up to usage, this customer will be protected.
Advantages of Off Grid
No more electrical bills.
Energy independence.
Protection from power outages.
Reliable source of power in remote locations.
Disadvantages of Off Grid
More expensive.
Not allowed in all states or countries.
No back up in the event of continuous bad weather.
Hybrid Systems
There is a middle ground for those who want the option to produce their own power but still have the reassurance that comes with being tied to the grid. Some customers decide to go to a hybrid system - one that is tied to the grid but also has a solar battery bank to store excess energy. This system can operate like an off grid system, but in the event of a streak of bad weather, the grid will be there to provide.