| Finding a way to decipher the different types of | | | | gas/diesel generator. By having other sources to |
| solar power systems in today's myriad of online | | | | charge your battery bank you can be assured |
| articles can be daunting and confusing to say the | | | | that during bad weather for a significant amount |
| least. Much of the public think that you have to | | | | of time will not discharge your batteries beyond |
| have batteries in order to have solar power, this | | | | their desired capacity. Hybrid systems can be "grid |
| is untrue, as a matter of fact most residential | | | | connected" or "off-grid". |
| solar systems being installed today are "grid tied" | | | | 6. Grid Connected without batteries - This is the |
| or "grid connected", without batteries. No batteries | | | | simplest and most widely used system at this |
| required! | | | | time. The components include a PV array, an |
| Photovoltaic systems can be configured in a | | | | inverter, and a two way meter from your utility. |
| variety of ways. This article will describe the 7 | | | | With this system you are using the utility grid as |
| main types of configurations and a few examples | | | | your storage device. when the grid is off or down |
| of their uses. | | | | so is your electricity. All inverters made for grid |
| 1. Battery charging systems with integrated | | | | tied systems must "sense" the electricity from |
| photovoltaics - This system charges the | | | | the utility grid or they will not work. How a |
| batteries of a complete component system. Like | | | | system like this works is the sun shines on the |
| backpacks that have a cellphone, iPod, or laptop | | | | array during the day (usually low load use) and |
| charger as well as the PV panels integrated within | | | | powers the appliances you use and the rest goes |
| it. Or something as simple as a solar powered | | | | to the utility grid in the form of a credit to you, |
| calculator. | | | | the power provider, at night (usually higher load |
| 2. Day use system - These systems | | | | use) you use those credits to power your home. |
| incorporate solar panels wired directly into a DC | | | | Simple right! |
| (direct current) appliance with no storage device. | | | | 7. Grid Connected with batteries - Solar systems |
| When the sun shines on the panels you have | | | | like these are virtually identical to "DC Systems to |
| power to the appliance. Some examples would be | | | | power AC and DC loads" and/or "Hybrid |
| remote water pumping or to operate fans | | | | Systems" listed above with the exception of |
| blowers or circulators for solar thermal systems. | | | | being tied to the grid. When the grid is off or |
| 3. DC system with storage batteries - The | | | | down your batteries then take over the job that |
| components for a system like this consists of PV | | | | the grid was doing. It is also referred to as "Grid |
| panels (or an "array"), a charge controller, and | | | | tied with a battery back-up". It is the second |
| storage batteries. The sun shines on the array | | | | most common type of system in use today. |
| and charges the batteries which is then used to | | | | Many commercial and institutional applications use |
| power DC loads (motors, appliances, and | | | | this type of system where uninterrupted power is |
| equipment that are powered by DC. For example | | | | essential. |
| a small "off-grid" cabin or some of the large | | | | Some of these systems are flexible to meet the |
| construction and road signs you may see on the | | | | needs of the individual project. Keep in mind that |
| highway. | | | | all of these systems, especially where batteries |
| These next 4 systems described require the use | | | | are concerned, are complex and need important |
| of an inverter to "invert" the DC (direct current) | | | | mathematical calculations in order to function |
| from the PV array or batteries to AC (alternating | | | | properly and efficiently. They all also need proper |
| current) to power AC appliances and to connect | | | | installation to comply with national, state and local |
| to the grid if desired. These are the most | | | | electrical codes (for example: disconnects, proper |
| common types of residential and small commercial | | | | marking of all system components and voltages, |
| industrial/institutional systems that are in common | | | | etc.) The national code is NEC (National Electrical |
| use now. | | | | Code) #690, this covers photovoltaics. |
| 4. DC System to power both AC and DC loads - | | | | These are the 7 main types of Solar PV systems |
| This system has essentially the same | | | | in use today. This will probably change as |
| components as the "DC system with storage | | | | technology changes. |
| batteries" listed above with the exception of the | | | | I hope this helps you out in your decision to go |
| inverter for AC appliances. These systems are | | | | solar and what system will work best for your |
| used in many off-grid applications because of the | | | | application and budget. |
| availability of common AC appliances and are | | | | To view an extended version of this article and |
| usually significantly cheaper than the same unit | | | | find out more about alternative energy for your |
| powered by DC. | | | | home Click Here or to get more info, links, and |
| 5. Hybrid Systems - Hybrid solar systems are a | | | | posts about solar, other alternative energy or |
| way to use other sources to charge the battery | | | | homesteading you can Click Here |
| bank such as a wind generator, micro hydro, or | | | | Peace and Prosperity to you. |