Solar Photovoltaic Modules.

September 17, 2021 amorphous, cells, concentrators, lenses, module, modules, monocrystalline, multicrystalline, polycrystalline, power, PV, thin-film No Comments

A PV module consists of many PV cells wired in parallel to increase current and in series to produce a higher voltage. 36 cell modules are the industry standard for large power production.

The module is encapsulated with tempered glass (or some other transparent material) on the front surface, and with a protective and waterproof material on the back surface. The edges are sealed for weatherproofing, and there is often an aluminum frame holding everything together in a mountable unit. In the back of the module there is a junction box, or wire leads, providing electrical connections.

Conventionally, PV modules are designed and manufactured for outdoor applications. Thus, they can operate under the sun, rain, and other climate impacts, which make possible the use of PV modules as potential components for external enclosures of buildings.

With the development in the past few decades, various types of PV module technologies are now available in the PV market, but not all these technologies are suitable for the integration or incorporation in building envelopes, since PV modules are traditionally designed mainly for power generation, and their functionalities as envelope elements are generally overlooked.

There are currently four commercial production technologies for PV Modules:

• Single Crystalline. This is the oldest and more expensive production technique, but it's also the most efficient sunlight conversion technology available. Module efficiency averages about 10% to 12%^[*].
• Polycrystalline or Multicrystalline. This has a slightly lower conversion efficiency compared to single crystalline but manufacturing costs are also lower. Module efficiency averages about 10% to 11%^[*].
• String Ribbon. This is a refinement of polycrystalline production, there is less work in production so costs are even lower. Module efficiency averages 7% to 8%^[*].
• Amorphous or Thin Film. Silicon material is vaporized and deposited on glass or stainless steel. The cost is lower than any other method. Module efficiency averages 5% to 7%^[*]

Module electrical connections are made in series to achieve a desired output voltage or in parallel to provide a desired current capability (amperes) of the solar panel or the PV system. The conducting wires that take the current off the modules are sized according to the current rating and may contain silver, copper or other non-magnetic conductive transition metals. Bypass diodes may be incorporated or used externally, in case of partial module shading, to maximize the output of module sections still illuminated.^{[citation needed]}

Some special solar PV modules include concentrators in which light is focused by lenses or mirrors onto smaller cells. This enables the use of cells with a high cost per unit area (such as gallium arsenide) in a cost-effective way.

Read More

Silicon - The Most Popular Material for Solar Cells.

September 16, 2021 amorphous, cell, crystalline, monocrystalline, polycrystalline, silicon, solar No Comments

Silicon - The Most Popular Material for Solar Cells.

The basic component of a solar cell is pure silicon, which has been used as an electrical component for decades as the silicon solar cell technology gained ground already in the 1950s.

Pure crystalline silicon is a poor conductor of electricity as it is a semiconductor material at its core. To address this issue, the silicon in a solar cell has impurities-meaning that other atoms are purposefully mixed in with the silicon atoms in order to improve silicon’s ability to capture the sun’s energy and convert it into electricity.

Solar cells made out of silicon currently provide a combination of high efficiency, low cost, and long lifetime. Modules are expected to last for 25 years or more, still producing more than 80% of their original power after this time.

There are mainly three types of Silicon solar cells:

MONOCRYSTALLINE		POLYCRYSTALLINE		AMORPHOUS

Read More

Monocrystalline Silicon Solar Cells.

September 16, 2021 bifacial solar panels, black hue, cells, crystal, czochralski method, ingot, monocrystalline, PERC cells, photovoltaic, silicon, single-crystal, solar, wafers No Comments

Monocrystalline.

Monocrystalline silicon cells, are the cells we usually refer to as silicon cells. As the name implies, the entire volume of the cell is a single crystal of silicon. It is the type of cells whose commercial use is more widespread nowadays.

The molecular structure of single-crystal silicon is uniform. This uniformity is ideal for the transfer of electrons efficiently through the material. However, in order to make an effective photovoltaic cell, silicon needs to be "doped" with other elements.

Monocrystalline silicon cells are made of silicon atoms connected to one another to form a crystal lattice. This lattice provides an organized structure that makes conversion of light into electricity more efficient.

Monocrystalline silicon solar cells are manufactured using something called the Czochralski method, in which a ‘seed’ crystal of silicon is placed into a molten vat of pure silicon at a high temperature. 

This process forms a single silicon crystal, called an ingot, that is sliced into thin silicon wafers which are then used in the solar modules.

Nowadays, there are several varieties of monocrystalline solar panels on the market to choose from. Passivated Emitter and Rear Contact cells, more commonly referred to as PERC cells, are becoming an increasingly popular monocrystalline option. PERC cells go through a different manufacturing and assembly process that increases the amount of electricity the cells can produce.

Bifacial solar panels, another monocrystalline technology, can generate electricity on both the front and back side of a module, and are gaining traction in commercial ground-mounted applications.

Monocrystalline solar panels are highly efficient and have a sleek design, but come at a higher price point than other solar panels.

Read More