| In Part 5 of this series, we'll discuss the type of | | | | for use at night or on cloudy days. |
| system that provides the most energy | | | | 6. System Meter |
| independence, the off-grid system. | | | | System meters are like the gauges in your car in that |
| Off-grid - A Definition | | | | they provide various measurements of your solar |
| Off-grid basically means that the household or | | | | electric system's performance, such as state of |
| building's electricity is supplied by means other than | | | | battery discharge, amount of electricity produced by |
| the grid, either via a solar power system or some | | | | the solar panels, etc. You can operate a solar electric |
| other source of alternative energy. | | | | system without a system meter, but it would be like |
| Components Of An Off-Grid Solar Electric System | | | | driving your car without the gauges - you'd |
| 1. Solar Panels | | | | constantly be worrying about which disaster was |
| As with all solar power systems, this is where it all | | | | waiting round the corner. |
| begins, with the solar panels collecting energy from | | | | 7. Main DC Disconnect |
| the sun and converting it into usable electricity. | | | | For off-grid systems, this is a must, since it provides |
| 2. Mounting Racks | | | | a way to quickly and safely disconnect the inverter |
| Once you've determined how many solar panels | | | | from the battery, thus avoiding electrical fires. |
| you're going to need to supply you with all the | | | | 8. Inverter |
| electricity for your household or business needs, the | | | | The inverter converts the DC electricity produced by |
| next step is to decide where to put them and how! | | | | the solar panels into AC electricity to run household |
| That's where mounting racks come in. Mounting racks | | | | appliances and devices. Off-grid inverters are usually |
| allow you to secure your panels either to the roof | | | | stored indoors, near the battery bank, since they |
| (usually) or on the ground (also an option, but | | | | aren't weather-resistant. |
| dependent on how much available land there is). | | | | 9. AC Breaker Panel/Inverter AC Disconnect |
| 3. Array DC Disconnect | | | | This panel contains labeled circuit breakers for all the |
| The array DC disconnect operates in the same way | | | | circuits in a household and prevents circuit overload. |
| as your household circuit breaker panel, in that it | | | | Since the inverter provides AC electricity to the |
| disconnects the solar array in case of an electrical | | | | house, a breaker needs to be added to the panel to |
| overload. | | | | protect the inverter circuit. |
| 4. Charge Controller | | | | 10. Backup Generator |
| Since a battery is a requisite component of an | | | | Even though these are loud and smelly, you'll need |
| off-grid solar power system, in the interests of | | | | one to complete your off-grid system in case of |
| extending the battery's lifespan, you'll need a charge | | | | extended periods of cloudy or inclement weather. At |
| controller. It prevents the battery from overcharging | | | | most, this will only be needed 50-200 hours a year, |
| and, if equipped with a low-voltage disconnect, | | | | and it's a whole lot cheaper than designing a solar |
| over-discharging, both of which can seriously reduce | | | | power system to cover worst-case scenarios. |
| the life of a battery. Take care of your battery, and | | | | If you're interested in total energy independence, |
| it'll take care of you. | | | | then this is the type of system for you. Once your |
| 5. Battery Bank | | | | system is installed, you can look forward to a future |
| A battery bank is a necessity for an off-grid system, | | | | of virtually free energy with zero environmental cost |
| since it stores electricity produced by the PV panels | | | | - good for your wallet and the future of the world. |