Archive for the ‘Solar Cell Basics’ Category

Thin Film Solar Cells

Thin Film Solar Cells (TFSC) are also known as thin film photovoltaic cells (TFPV) are ultra thin solar cells that convert the suns radiated spectrum into electricity using the photovoltaic principle. Thin Film Solar Cells are used in a wide variety of installations but were primarily designed for calculators, watches and small power rechargeable batteries.

How Are Thin Solar Cells Made?

Thin Film Solar Cells are created by layering photovoltaic material onto a substrate material. Depending on the output required more than one layer can be applied. Thin Film Solar Cells vary in thickness from nanometers to tens of micrometers. Thin Film Solar Cells are usually categorized by the materials that are used to create the cells. There are four main materials employed but of the four two are more common than the others. The most common material employed, is:

Thin Film Solar Cells

Amorphous Silicon (a-Si)

An Amorphous thin film cell uses Nanocrystalline (nc-Si), Protocystalline, or Black Silicon in its manufacture. This material differs from the more usual Monocrystalline or Polycrystalline wafer used in the manufacture of normal solar panels. The silicon is layered into the substrate material by a technique known as chemical vapor deposition although other means are being explored. The next common material used in thin Film Solar Cells is:

Cadmium Telluride ( Cd-Te)

These types of Thin Film Solar Cells uses two common materials Cadmium and Telluride, and is slightly more expensive to produce than the Amorphous Thin Film Silicon solar cells because they are both rare earth elements. Another less common group of materials is:

Copper, Indium, Gallium, Selenium (CIGS)

The number of rare earths involved in this photovoltaic combination makes raises production costs. However of all the combinations of rare earths this one is thought to be able to achieve the holy grail of grid parity given sufficient demand and production. Finally the last combination of elements is:

Thin Film Silicon ( TF-Si)

This is Silicon that is reduced to molecular size and then deposited on the substrate material. The output of this type of Solar cell is slightly inferior to the rest of the above. Nevertheless it was one of the first materials to be employed in manufacturing Thin Film Solar Cells.

Thin Film Solar Cells Problems

One of the most pressing problems facing the Thin Film solar Cell industry is the availability of the rare earth elements required for this technology. Virtually all the rare earth elements at this time are mined and refined in China. Until other sources such as Africa come on stream the price of these rare earth elements will always remain high.

Thin Film Solar Cells are now becoming main stream and are being incorporated into buildings both installed on the roof and in the wall panels. Thin Film Solar Cells are very rugged and light and can be semi transparent for use to cover windows and other areas of glass. The Thin Film Solar Cells also act as window tinting while they are producing power.

The future of solar cell is definitely Thin Film Solar Cells. The higher electrical output of these panels and their ease of installation make the object of achieving grid parity evermore closer.

Solar energy has replaced the conventional energy resources with its potential results and capacity. It leads the list of renewable energy resource. There are many methods to create and store solar energy. Let us discuss the six different types of solar energy in this article.

Solar cells: Whether it is a pocket calculator or a high-end electronic device, you might have seen solar cells playing the main role. These cells are arranged in various patterns or arrays which are called as panels. The solar panels are made of Silicon and act as semiconductors. They are useful in generating electricity using the sunlight.

Solar Fibers: This technology uses solar tape made of Titanium dioxide. Their functions are similar to that of the solar cells. The only difference which distinguishes solar fibers is that it does not use silicon. The solar tape is used in building materials, manufacturing cars and clothing.

Solar Updraft Tower: The basic concept of solar updraft tower is to drive turbines using the solar energy. Air is left to pass through a green house kind of structure. It gets heated along the passage and is channelized through a tower. The hot air rises up and drives turbines.

Solar Pond: The main purpose of a solar pond is to produce heat and not electricity. It is big structure with three layers. The topmost layer has low salt content. The middle layer has medium amount of salt which acts as an insulator. It prevents heat convection in the water. The bottom most layer consists of high level of salt which traps the heat. The temperature of this layer can go very high at times. The trapped heat is used to warm up buildings, homes or produce electricity.

Solar Chemical: Chemical reaction is used in this method to generate electricity out of sunlight. Not much can be discussed about the use of this method as it is still in its nascent stage. All we know is most of the researches are based on photo electrolysis of water.

Energy Tower: This method is very much similar to solar updraft tower. Water is sprayed on the top of the tower. The water is then evaporated and cooled inside the tower. The cold air gets heavy and lands on the turbines driving them smoothly.

Though many researches are being carried in this field, solar cells are the ones which are widely used and known by common man.

There are many challenges striking our planet every now and then. One of them is global warming and intensive pollution. The ozone layer that protects the earth from the harmful UV rays of the sun is getting worn out and damaged every day. Who is responsible for the destruction? Of course, we human beings! We can stop this destructive act by taking few measures. One of them is using renewable energy resources such as solar power.

Until few years ago the tremendous heat and light emitted by the sun was unnoticed. Solar energy is constant and free source of energy which can be harnessed continuously. Utility companies and homes have huge solar panels set up to receive unpaid energy from the head of the solar system. Though there is much to say about the advantages of solar energy, only drawback is consistency. The solar cells work well on sunny and bright days whereas on a cloudy or foggy day they do not supply constant energy. To avoid this solar energy has to be stored. There are few methods to store solar energy. Let us discuss them in detail.

Photovoltaic Solar system

The solar energy can be stored using a photovoltaic system in 2 different ways – Grid and Battery banks. The grid uses net-metering. When excess of solar energy is produced it is sent to the grid. During this process the meter rolls backwards and when you use the stored energy, the meter rolls forward.

Battery Bank

A battery bank system constitutes of 4 main components:

Battery bank: It looks similar to the car batteries. A group of batteries are tied up to form an energy bank. They are devised to tolerate charging and discharging actions of solar energy.

Charge Controller: It is a controlling device set in the instrument. It prevents the battery from getting over charged.

Main DC Disconnect: It is a DC breaker that disconnects the batteries from the inverter for servicing purposes.

System Meter: Just like any other meter it displays the performance and the status of the solar panels.
Battery bank storage suits home and office.

Solar Thermal Storage

Solar Thermal storage systems are used for solar pool heating, solar space heating and solar water heating.
Solar water heating systems uses huge tanks filled with water to capture solar power. Solar space heating systems use water tanks and thermal mass to store solar energy. Thermal mass captures the energy during the day and releases it at night. Solar pool heating system uses the water in swimming pools to store energy.