Photovoltaic Cells

At the heart of every solar power energy system is the photovoltaic cells. When a certain number these cells are clustered together to form solar panels, which are electrically connected to each other and then mounted in a support frame, the result is the larger photovoltaic module. These photovoltaic modules, in turn, are designed to supply electrical power at a certain voltage to the household appliances connected to the solar power energy system.

To understand the process by which radiant energy from the sun 93 miles million away becomes electrical energy used in the homes on Earth, it is important to understand photovoltaics in general and photovoltaic panels in particular. This article will briefly describe such concepts in ways that a do-it-yourself enthusiast who wants to install a solar energy system in his home can understand and understand well.

Explanation of Photovoltaics

So, what exactly is photovoltaics (PV)? Simply put, it is the method of generating electrical power through the conversion of solar radiation energy into direct current (DC) electricity with the use of semiconductors. These semiconductors are composed of photovoltaic cells grouped together to form solar panels, thus, the alternative names of photovoltaic panels and photovoltaic modules given to these products.

It must be emphasized, however, that photovoltaics may be used specifically in reference to electricity generated from sunlight but the term is more accurately applied to the field of research and technology related to the numerous applications of photovoltaic materials in the generation of electricity from light. The light source is not necessarily sunlight since photovoltaic cells can also detect electromagnetic radiation near the visible range of the spectrum.

Description of the Photovoltaic Effect

Any discussion of the area of photovoltaics will be incomplete without the mention of the photovoltaic effect. Basically, it is the creation of voltage in the material upon its exposure to the light source. The photons of light excite the electrons in the photovoltaic material into a higher state of energy such that a transfer between different bands, say, from the valence to the conduction bands, is created. In turn, a voltage is generated between the two electrodes of the photovoltaic cells.

Because most photovoltaic applications use sunlight as the source of radiation energy, the devices used to create electricity are then called solar cells. Bit as previously mentioned, the photovoltaic effect can be generated by other sources of electromagnetic radiation.

Description of Photovoltaic Panels

Nowadays, solar power energy systems use photovoltaic panels made from monocrystalline silicon, polycrystalline silicon, and amorphous silicon. With advances in technology, other materials like cadmium telluride and copper indium selenide/sulfide are also being incorporated into existing photovoltaic cells. In general, solar cells refer to the individual solar panels while photovoltaic arrays refer to the numerous agglomerations of solar panels over a vast area of land although both are often interchanged in conversations.

The properties of each type of solar panel obviously depend on the materials used to manufacture it. At present, there are three main types of solar panels that can be used for residential applications with each type offering unique pros and cons. Do-it-yourself enthusiasts who desire to install solar power energy systems in their homes must carefully consider each type of solar panel before making the decision.

Your decision will be largely influenced by the factors of purchase cost, energy efficiency of the photovoltaic cells in the panels, and expected electricity requirements from the system, among others. If possible, ask for the expert opinion and assistance of professionals when choosing from these three types of photovoltaic panels. Or if none exists in your area, the best option for DIY enthusiasts is always to look for reliable information from e-books, video instructional materials and text resources.

The types of solar panels to choose from as well as their pros and cons are the following:

• Monocrystalline solar panels are the most popular panels in the commercial sector because of their high energy efficiency performance, proven durability over a period of 25 to 50 years, and low energy reduction of 12 percent in strong sunlight, among other pros. Their expensive price tags, however, discourage many homeowners from buying monocrystalline panels with said prices due to the fact that the photovoltaic cells are made from a single silicon crystal requiring a sophisticated manufacturing process to perfect.
• Polycrystalline solar panels are made by fusing multiple silicon crystals to form a single block. The manufacturing process produces the square-shaped panels arranged in a mosaic. These panels are also popular because of their affordable prices, ease of installation for DIY enthusiasts and durability over the long term period. Take note that energy efficiency is lower at just 12 percent conversion.
• Amorphous solar panels are made from conductive silicon on one layer and another layer of solid plate of glass. The panels are divided into several sections of photovoltaic cells with the silvery side as the conductive side and the sun-facing side with a dark brown color. (In contrast, monocrystalline panels have a black to iridescent blue hue) Again, energy efficiency for amorphous solar panels is lower in comparison with the monocrystalline solar panels but this is offset by the former’s more affordable price, stronger frame and smaller dimensions.

As a beginner, it can be difficult to choose which one is the most suitable for the solar energy system being planned. The following considerations are the most important for the first-time DIY enthusiast of solar power:

• Cost – Yes, the polycrystalline and amorphous solar panels may be the most affordable options but this is not the be-all and end-all of choosing the panels. Look into the certification of the product to determine if it qualifies for the government (federal, state and local) rebates, incentives and grants that can often lessen the costs of installation by as much as 30 percent in many states.
• Energy Efficiency – When going off the grid, energy efficiency is often the most important factor than the initial installation cost.

It is also important to look at the versatility, durability and longevity of the photovoltaic cells, panels and modules being considered for purchase, installation and maintenance. Look for guidance in the wise choice of these renewable energy-related products from e-books and other instructional materials, all of which are available online.