| The first thing you might ask - what is solar radiation | | | | poles are connected makes a big difference. Connect |
| and how does it related to solar generated electricity? | | | | Solar Panels in Series |
| A good question and one that is discussed in one of | | | | When you connect residential solar energy systems in |
| our article dedicated to home solar power. This article, | | | | series, you connect the positive (+) pole on one |
| on the other hand, explains how kilowatts are | | | | component to the negative (-) pole on the next. When |
| calculated based upon the energy output of your solar | | | | modules are connected in series, the voltages are |
| array. We will also highlight the difference between | | | | added. Adding voltage together in this fashion creates |
| solar cells connected in parallel versus in series. | | | | a long chain of solar modules all working together, |
| The average American home uses about 25 kWh of | | | | depending upon each other, and creating a flow of |
| electricity per day. The following example illustrates | | | | current that increases along the length of the system. |
| how to calculate the power produced by a residential | | | | These modules in series are called Strings. The |
| solar energy system. By consulting a solar radiation | | | | average string is 8-12 modules so the voltage would |
| map, we find that a house receives 5 hours of direct | | | | be 320 - 480. Unfortunately, we encounter some |
| solar radiation a day, averaged out throughout the | | | | negative aspects of of this type of construction. |
| year. | | | | Connecting Solar Panels in Parallel |
| Solar radiation maps are highlighted on may websites | | | | When you connect solar panels or components in |
| throughout the Internet. You can do a quick search for | | | | parallel, you connect the panels so current can travel |
| "solar radiation" to find one. They essentially plot the | | | | to your inverter and to your house via multiple paths. |
| amount of sunlight based upon time of year and | | | | Unlike adding solar modules in series which increases |
| physical location that will hit the United States in any | | | | the volume of current as it goes, the solar panels |
| given area. | | | | connected in parallel has the effective of leaving the |
| Calculating the power from a solar energy system | | | | current or volume of electricity passing through the |
| Divide the average kWh per day by the average sun | | | | system the same. |
| hours per day. For this example, we take 25 kWh | | | | Solar panels or strings of solar arrays tied together in |
| divided by 5 hours of sun per day = 5 kW system | | | | parallel are called parallel systems. Their amps are |
| This 5 kW system will generate 25 kWhs under | | | | combined together but the total voltage remains the |
| optimal conditions in direct sunlight for 5 hours, or 25 | | | | same. Adding amps is like increasing the volume, the |
| kWh on an average day with some at peak | | | | pressure stays the same but the volume goes up. |
| production and most of the sunlight at less than optimal | | | | Inverters can only handle so much volume so you will |
| angles. | | | | seldom see more than 1 to 3 strings in parallel; positive |
| Future articles related to solar energy will continue to | | | | ends to positive ends with negative ends to negative |
| explain the effects of sun angle, reflection, and | | | | ends. |
| refraction on the design, output, and installation of solar | | | | One of the advantages of parallel connection is that |
| panels. | | | | electricity continues to flow, even though one of the |
| Energy as it Pertains to Solar Modules | | | | components (or strings) is damaged. If a system is |
| Individual solar modules that are measured in watts | | | | entirely in series, one damaged component stops the |
| have a particular voltage (around 40 volts) and a | | | | entire system. You may remember the |
| particular amperage (around 5 amps). A solar module | | | | ever-frustrating Christmas lights that were connected |
| with 40 volts and 5 amps is called a 200-watt module, | | | | in series. Often difficult to trouble shoot, strings of lights |
| which means that it has the potential to produce 200 | | | | connected in series are hard to fix when one bulb |
| watts of electricity when in direct sunlight, away from | | | | blew out. Now, the modern Christmas lights are |
| trees or shading, and clear of snow or debris. Since | | | | connected in parallel. You can see this because there |
| most electrical components around your house are | | | | are two wires connecting each lamp. You can feel this |
| only rated for 600 volts DC, it is rare to see a solar | | | | via their less frustrating maintenance and operation. |
| array with a string larger the 15 solar modules. On the | | | | Options for Residential Solar Energy Systems |
| other hand, since inverters need a minimum voltage or | | | | In this article, we explained in some detail how solar |
| pressure to turn them on, you will seldom have a solar | | | | modules calculate the power they produce as well as |
| array with a string solar modules with a size smaller | | | | how connecting solar arrays in series or parallel can |
| then 6. | | | | have an large impact on energy output as well as |
| Electrical components, like solar cells, panel modules or | | | | complexity of design. Our next article will cover how |
| batteries, can be connected in either series or parallel. | | | | sun angle affects solar energy systems and how to |
| This makes a big difference in the total quantities of | | | | quantify the solar power produced from the sun. |
| energy produced from the solar energy system, as | | | | New solar energy system rentals allow you to |
| well as the stability of the technology over time. Each | | | | upgrade your home to solar generated electricity with |
| solar module or component has a positive and a | | | | no large system to purchase. You can rent the solar |
| negative pole. In essence, this is the same way | | | | energy equipment needed to generate up to 100 |
| batteries have their negative and positive poles | | | | percent of your electricity needs. Exciting aspects |
| arranged. Take a look at how you but batteries in a | | | | related to clean, green solar energy are emerging all |
| flashlight. Same idea here. The manner in which these | | | | around us. |