Photovoltaic cells and modules come in several different sizes. The most common is often 10cm by 10cm and this size has the capacity to generate about half a volt of electricity. Of course photovoltaic cells are combined or bundled together in solar panels in order to produce larger amounts of electricity at a time for best results. This is the only way solar energy would e possible for the masses; residentially as well as commercially. To give you an example, if you have a 12volt module or solar panel there are more than likely at least 30-40 photovoltaic cells within this panel to transform the sun into electricity upon impact.

Benefits of Photovoltaic Cells

• Produces completely free electricity
• The sun is never going to be depleted within our lifetime
• They covert 15% of the sun’s light into electricity
• Almost zero maintenance is involved
• No moving parts, liquids or chemicals needed to make this happen
• Available everywhere on earth

There are many benefits associated with the technology of solar power brought to us by photovoltaic cells but there are also several disadvantages that should be noted here as well. If you have not yet looked into solar panels for your personal home or cottage you will soon find out that the cost of solar panels is quite expensive and for many people is not quite an option financially. It won’t be long before the initial cost of solar panels will become more affordable to the masses but for now it is a major expense. Remember, after the initial cost of solar panels and proper installation you will be living on free electricity for the rest of your life; this is an energy and money saving goal we can all get on board with.

Sizing your Photovoltaic cells and panels can be a difficult task. You want to ensure that you get enough cells to power your home or cottage on rainy and cloudy days as well as sunny days. What this means is enough cells to store the energy to be used on days when the sun is not directly powering the home. This is an aspect that is often over looked because we assume the sun is out everyday which it is, but it is not always a bright and sunny day. The estimate just how many cells you will need to power your home a simple calculation can be done. Start with one electrical device at a time and multiple its power in watts by the number of hours a day it will be on. Go through each and every device and your home and you will find the number of watts you need each and every day to power your home as it is now.

Based on solar energy and photovoltaic cells you can save a great deal of money in the long run and help save the planet at the same time. It is time we allow the natural resources of our planet to guide our lifestyles and solar energy is the first major breakthrough we can all utilize in some form or another.

Any solar architecture that seeks to achieve ultra-high power conversion efficiencies must efficiently harvest the considerable energy of high-energy (blue) photons from the sun, and yet absorb low-energy (infrared) photons as well.  Our first architecture will be based on multijunction devices: layers of different-bandgap photovoltaic cells stacked atop one another. The power from each layer will be added together either within the device or through an external circuit.
We will also pursue the realization of high-efficiency solar cells based on new classes of colloidal quantum dots.  Successful optoelectronic devices based on this class of materials have, until now, included heavy metals such as lead or cadmium as constituent materials.  We will optimize the properties of colloidal quantum dots that do not contain heavy metals, showing that these can be transformed into efficient solar energy harvesting devices.

We are tackling a challenge that is innately interdisciplinary.  It spans materials chemistry, device fabrication, device optimization, careful optoelectronic characterization, and even ultrafast spectroscopic investigation.  The research project will dovetail with KAUST’s Solar Energy Research Center, with planned exchanges of personnel, know-how, and experimental capacity between the KAUST and University of Toronto-based collaborating teams.

Dr. Edward Hartley Sargent, KAUST Investigator, is a professor and Canada Research Chair in Nanotechnology at the University of Toronto in Canada.  Dr. Sargent is a world-renowned scientist who was named “one of the world’s top young innovators” by Technology Review (an MIT publication).  He was also named to the Scientific American 50 for his achievements.  In 2002, he won the Outstanding Engineer Award of the Institute of Electrical and Electronics Engineers of Canada.  He is author of the book The Dance of Molecules: How Nanotechnology is Changing Our Lives.

Source: paint-on-solar-cells

­­T­he solar cells that you see on calculators and satellites are photovoltaic cells or modules (modules are simply a group of cells electrically connected and packaged in one frame). Photovoltaics, as the word implies (photo = light, voltaic = electricity), convert sunlight directly into electricity. Once used almost exclusively in space, photovoltaics are used more and more in less exotic ways. They could even power your house. How do these devices work?

­Photovoltaic (PV) cells are made of special materials called semiconductors such as silicon, which is currently the most commonly used. Ba­sically, when light strikes the cell, a certain portion of it is absorbed within the semiconductor material. This means that the energy of the absorbed light is transferred to the semiconductor. The energy knocks electrons loose, allowing them to flow freely. PV cells also all have one or more electric fields that act to force electrons freed by light absorption to flow in a certain direction. This flow of electrons i­s a current, and by placing metal contacts on the top and bottom of the PV cell, we can draw that current off to use externally. For example, the current can power a calculator. This current, together with the cell’s voltage (which is a result of its built-in electric field or fields), defines the power (or wattage) that the solar cell can produce.

Source: Photovoltaic Cells