Solar Panels for Home – the next questions

by Andy Goldman on March 6, 2013

By now you have decided that Solar Panels are good for you and your home. You have read our article Solar Panels for Home – the initial questions and you ready to proceed with the installation of solar panels on top of your house, on the roof.  Well we believe that you are now at the second stage of the solar panel education and you need to address some more scientific or engineering type questions.

What are the different types of solar panels?

When we refer to solar panels we actually refer to photovoltaic, PV, solar panels, that are panels which convert the power from the sun to electricity. Currently there are three commercially available PV technologies which are used for the production of solar panels. These are: Monocrystalline silicon, Polycrystalline Silicon and Thin Film.

Monocrystalline Silicon. Monocrystalline is also known as single crystal, since mono is the Greek word for single, and it is the first PV technology introduced in 1955. This kind of technology is known for performance and durability. Single crystal modules are made of cells which are cut from single continuous crystal and because of the fact that they are cut from a single crystal they have a uniform dark blue color. The material is sliced into thin circular wafers.

Polycrystalline Silicon. They are made from a similar silicon material as the Monocrystalline silicon but instead of being cut they are melted, poured into a mold and then cut into square wafers. They are slightly less efficient than the Monocrystalline.

Monocrystalline and Polycrystalline silicon are the most widely used technologies used for the construction of PV cells. They have efficiencies varying from 11% to 16%

Thin Film. Thin Film, as the name implies, is the technology where thin films of silicon is deposited on thin metal or glass to form the thin film PV technology. Then these thin films are deposited next to each other thus forming the bigger PV cell. They are less efficient than the mono or poly crystalline silicon PV cells but they cost less. Thin film technology is sometimes called amorphous which means non-crystalline and the material is made of,  is most of the times silicon but it can also be other materials with photovoltaic effects.

What is the efficiency of PV cells technologies?

Now that you can understand the different technologies which are involved in the manufacturing of Solar Panels you may be wondering what’s in it me? What is the difference between them which will affect my decision? The difference would be in efficiency and price. The two differentiating factors are inversely proportion to each other and obviously the optimal combination would be to get the lowest priced solar panel with the maximum efficiency. The efficiency of these technologies is as follows:

Monocrystalline Solar Panels: The recorded efficiencies observed for Monocrystalline solar panels are within the range of 18-24% depending on manufacturer and the specialized manufacturing process they use.

Polycrystalline Solar Panels: This kind of panels have less efficiency and lower price than the Monocrystalline panels. The efficiency of Polycrystalline Solar Panels is in the range of 14-17%.

Thin Film Panels: Thin Film Panels come in five different technologies with just one being a silicon based technology and each of the technologies has its own efficiency percentage. These are:

  • Amorphous Silicon Technology with efficiency range 9-10%
  • Copper Indium Gallium Diselenide with efficiency range 11-14%
  • Copper Indium Selenium with efficiency around 11.5%
  • Cadmium Tellurium with efficiency around 12% even though certain manufacturers claim efficiencies of around 15%
  • Copper Zinc Tin Sulfur Selenium and despite of the fact that it is the newest technology of all Thin Film technologies the achieved efficiency is in the range of 9-10%.

Solar Panels for Home - the next questions

Do you need Batteries for your Solar Panels?

The answer to this question depends on how critical it is for you to have an uninterruptible power supply at your house. Batteries are electricity storage units and they are used to provide electricity when at nights, when there is no Sun to produce electricity, you have power outages.

Even though this seems to be a good idea, to have a backup source, there are two cons involved. The first disadvantage is the cost involved and the more backup power we want the more costly the solution is. The second disadvantage is the complexity introduced in the connectivity with introduction of Batteries in the connectivity circuit.

There three different type of batteries which can be used. These types of batteries are the ones which are used with most of the renewable energy sources. These are: Flooded Lead Acid, Gelled Electrolyte Sealed Lead Acid and Sealed Absorbed glass Mat.

Really the decision of installing Batteries connected to your Solar Panel is yours. If your installation is an off-grid installation then we believe that you have no choice than to install batteries so that you will have power during the night but if you are connected to the grid you can avoid batteries by talking a calculated risk knowing that power cuts in your area are not a frequent phenomenon.

As conclusion we can state that as a current or future Solar Panel owner you need to be as educated as possible so that you would make the right decision and choice when it comes to install a Solar Panel for you home.

About the Author

Andy Goldman

Andy Goldman is a 27-year veteran in the service industry with managerial, strategic, operational and consulting experience. Has managed teams of 5-45 people and has also managed several multidiscipline projects. He has worked in Europe and the USA and holds a BSc and MSc in Electrical Engineering and an MBA with a minor in Finance. For the past 5 years he has been an enthusiast of renewable technologies. Article by Andy Goldman You can connect with Andy Goldman at Google+

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