Power systems vary in design depending on what energy sources are used and what purpose they must fulfill.
There are essentially three types of solar power systems:
Solar and Wind Grid-Tie Systems
Also called grid-interactive, grid-intertie, utility-interconnected and other such terms, grid-tie solar systems built onto your building and property that connect directly into the electric utility feed.
This is possible in areas that allow net-metering, whereby a solar or wind powered system turns your electric meter backwards when it is producing more power than you are using. This type of system provides no backup power when the utility fails. Use Solar PV panels such as REC Solar 250 watt 24 VDC. Combined into solar PV arrays large solar power generation can be fed back into the grid. SunnyBoy grid tie inverters are used to push solar energy into the electric grid.
Solar and Wind Grid-Tie Systems with Battery Back-up
a grid-tie system with battery backup feeds excess solar electricity to the grid and provides backup power when the utility grid is down. With this type of system you sacrifice some power generation efficiency in exchange for having power when there is a utility power failure. The amount of backup power you have depends on the size of the battery and electrical loads that draw on them.
Solar and Wind Off-Grid Systems
This type of power system is independent of the utility grid. It can use solar modules, a wind generator, a micro-hydroelectric generator, or a combination of any or all of them to produce your electric power. Owners of this type of system often use a gas or diesel generator for backup when the power system does not meet all of the needs. Use solar PV panels like SolarTech 125 watt 12 VDC, or REC Solar 250 watts 24 VDC to charge batteries.
Wind generators including Air X, Air 30, Air 40, Air Breeze are great battery chargers. Battery charging voltage 12/24/48 VDC. Whisper 100 wind generator is ideal for charging batteries 24/48 VDC. Combine solar PV panels and wind generators for solar and wind home power systems.