| In Part 3A of this series, we'll discuss the second | | | | concerned). |
| type of system used to produce solar power, the | | | | 3. DC Disconnect |
| grid-tied system with battery backup. Here we'll | | | | If a current overload was to occur, the array DC |
| cover the components from the PV panels to the | | | | disconnect would enable you to safely interrupt the |
| battery bank and associated items. | | | | electrical flow from the solar panels. |
| Grid-tied - A Definition | | | | 4. Charge Controller |
| This was covered previously in Part 2 of this series, | | | | If you're using a system with a battery back-up, a |
| but, briefly, to recap, a grid-tied solar power system | | | | charge controller is a necessity. It regulates the |
| produces electricity that is fed into the utility grid, and | | | | amount of power flowing to and from the battery, |
| then, from the grid, back into the home. | | | | and prevents overcharging, and, if it has a |
| The advantage of adding a battery as a backup is | | | | low-voltage disconnect, over-discharging, both of |
| that, should there be a blackout or loss of power | | | | which can seriously damage the battery. The moral |
| from the grid, the electricity stored in the battery | | | | to this story - be nice to your battery, and your |
| can be used to keep your household running. Which | | | | battery will be nice to you! Hence, the need for a |
| means you'll be able to eat - great! The downside is | | | | charge controller - it's like your battery's Mum! |
| that this type of system is significantly more | | | | 5. Battery Bank |
| expensive due to the additional components required. | | | | A battery bank stores electricity from the PV panels |
| Components Of A Grid-Tied Solar Electric System | | | | for use in case of a blackout. There are several |
| With Battery Backup | | | | different types of batteries available, but the one |
| 1. Solar Panels | | | | that's best for grid-tied systems is the sealed |
| The solar panel, which goes by a variety of epithets, | | | | absorbent glass mat (or AGM), which requires no |
| including solar module or photovoltaic (PV) panel, is | | | | maintenance (=potentially less headaches!) and is |
| where the whole process of turning solar energy into | | | | designed to be kept fully charged, typically what |
| usable electricity begins. A single panel consists of a | | | | you'd need for a grid-tied system. |
| number of cells that contain silicon, and these react | | | | 6. System Meter |
| with the sunlight to produce DC (direct current) | | | | This is used to monitor the status and performance |
| electricity. | | | | of your grid-tied system, including the state of |
| In order to run appliances within the home, several | | | | charge of the battery bank, PV panel productivity |
| panels will be needed to produce enough solar | | | | and electrical consumption. While this is an optional |
| electrical power. These panels will be joined together | | | | piece of equipment, it is highly recommended, |
| to form an array. | | | | otherwise you'll be completely in the dark as to how |
| 2. Mounting Racks | | | | well or not your system is performing and if |
| Having determined how many solar panels will be | | | | something needs tweaking. A bit like driving your car |
| needed to cover a home's solar power requirements, | | | | without a gas gauge - not the best option. |
| the next thing to work out is where to put them and | | | | As you can see, this type of system is quite a bit |
| how. The "where" can be either on the roof (the | | | | more complex than the relatively straightforward |
| most common option), on poles set in concrete or on | | | | grid-tied solar power system (see Part 2 of this |
| the ground. The "how" is where mounting racks | | | | series). And that's just half of the system. We'll |
| come in. Mounting racks are used to secure and | | | | cover the rest in Part 3B, so please check back for |
| orientate the PV panels (south-facing is generally best | | | | the next installment. |
| as far as the amount of available sunlight is | | | | |