By PV Mike
We all know (or have been told) that solar power is simply power provided by the sun. But how does the process actually work? As an amateur solar enthusiast I’ll try and explain the process for you so that you have a better understanding of the entire process from sunlight (or light source) to the end result of power being produced.
What are Photovoltaics?
The term “” has been gaining popularity in the energy industry. Most countries—especially the industrialized and economically prosperous ones—are finding themselves in short supply of traditional energy sources to ensure that their industries are adequately powered. Fossil fuels have been the traditional source of energy for centuries, but they are not sustainable and might run out over time. Rising oil prices have also clued many nations in how fossil fuels can be vulnerable to depletion. Plus, the rising levels of pollution in many areas of the world are ringing alarms everywhere.
Experts have been searching for clean and sustainable sources of energy for decades, and they have made a breakthrough: harvesting sunlight and turning it into energy that can power all our wonderful inventions and innovations. This method of sourcing energy from a clean and renewable source—the sun—is known as photovoltaics. This method involves collecting solar radiation and turning it into electrical power through the use of semiconductors.
The Photovoltaic Effect
Harnessing the power of the sun and turning it into electric currents is powered by the photovoltaic effect. Simply put, the photovoltaic effect involves creating electric currents or voltage in a certain material by exposing it to light. First observed by a French physicist named Edmond Becquerel in 1839, the photovoltaic effect is greatly influential in the development of the solar power industry. Becquerel is also credited for creating the first photovoltaic cell in the world.
In his experiments, he discovered that silver chloride (placed in an acidic solution) connected to several platinum electrodes could generate electric currents and voltage when placed under light. As recognition for this breakthrough experiment, the photovoltaic effect is alternately known as the Becquerel effect.
Clean and Sustainable Source of Energy
Many scientists and energy experts believe that using photovoltaics in power generation is the clean and sustainable way to go. This seemingly complex technology is powered by the best kind of renewable energy our planet has: the sun. Sunlight is not only abundant (during daytime, of course, and more so during warmer weather and in areas near the equator), but is also distributed in almost every corner of the planet.
One of the major advantages of photovoltaics is that generating power through this technology does not produce environmental emissions during the process—therefore reducing the pollutants released into the environment during power generation.
The technology of photovoltaics is well-proven and used for more than fifty years, with more and more countries and industries building their own systems to supplement their use of electricity and other sources of energy. In the future, energy experts are hoping that photovoltaics can fully take over the other means of electricity generation.
Photovoltaics Around the World
As of 2013, the use of solar power for electrical energy has reached a record height of 136 GW, which experts approximate to be enough to meet 0.85% of the world’s electricity demand. China, one of the world’s leading consumers of fossil fuels, has a fast-growing market for photovoltaics. Germany, long known to be one of the world’s leaders in technology, is the largest producer of sun-sourced electrical energy; the country uses six percent of photovoltaic energy for its electricity needs.
How Photovoltaics Work
Solar power is credited to be one of the most important breakthroughs of the last century. Harnessing the power of the sun is seen by many scientists and energy experts as the solution to our dependency on fossil fuels, which are not only contributing to environmental pollution, but can also be depleted over time. Photovoltaics has been used in different parts of the world as a means to supplement electricity demands, and energy experts are optimistic that the growth of the solar power industry means that we could expect a higher annual generation of electricity through this process.
The word “photovoltaic” was derived from the Greek word “phos” (light) and “volt,” which was derived from Alessandro Volta, the Italian physicist who invented the electrochemical cell. Photovoltaic cells, also known as solar cells, is basically a type of electric device that has the ability to convert light energy into electricity through the photovoltaic effect.
The photovoltaic effect is also known as the Becquerel effect, named after the French physicist Edmond Becquerel who discovered it in 1839. At the tender age of 19, Becquerel experimented with silver chloride (in an acidic solution) and platinum electrodes. When connected and exposed to light, the chemical and the electrodes generated electric currents and voltage. This “little” experiment won Becquerel a seat in the Royal Swedish Academy of Sciences.
Photovoltaic cells are the core of the technology. There are three basic attributes to a photovoltaic cell. First, it has the capacity to absorb light and to generate excitons or electron-hole pairs. Second, it has the capacity to separate charge carriers with opposite types. Finally, it has the capacity the separate the extraction of charge carriers to an external circuit connected to it.
Photovoltaic cells are made with semiconductor materials, with silicon as the most used material in the industry. The solar cells are semiconductor wafers, which are treated with chemicals that allow the formation of electric field. When exposed to light, the electrons on the semiconductor material will be loosened from the atoms they are attached to. The electrical conductors connected to the positive and negative sides of the solar cell will then form an electrical circuit, and the loosened electrons will then be captured as an electrical current.
When connected to each other and mounted on a frame, solar cells will form a photovoltaic module. These modules are often designed to generate and supply electricity at a specified voltage, with 12 volts being one of the most common kinds of solar modules. Since these modules depend on solar power, the amount of electricity that they can generate is dependent on the amount of light that they absorb.
When wired together, multiple modules form an array. The larger the array (or, the more modules grouped together), the higher amount of electricity it can produce. Solar arrays generate direct-current (or DC) electricity, and can be connected in either a parallel or series electrical arrangement to deliver the current and voltage combination needed.
The Application of Photovoltaics
Photovoltaic technology—or the use of solar energy to generate electricity—is one of the best breakthroughs in the field of power generation. Since the photovoltaic effect was discovered by A.E. Becquerel in 1839, the technology has proven to be reliable, cost-efficient, clean, and renewable. The benefits of solar power technology dramatically outweigh the disadvantages involved with the use of photovoltaic systems.
There are a good number of applications for photovoltaic technology, including the following:
Photovoltaics for the Home
One of the places that will greatly benefit from photovoltaic systems is the home. Installing a solar power system in your home to augment your electrical supply will not be only cost-efficient, but will be a great step toward minimizing your carbon footprint and dependence on pollution-emitting technologies. Finding a small and affordable solar power system for your home is very easy, and they make for a quick and easy installation. Even the White House has installed its very own photovoltaic system to show Americans how cost-efficient and environment-friendly a solar-powered house is.
Photovoltaics for Business
Cutting overhead costs in order to maximize profits is a major goal for many companies. One of the biggest cost chunks in the overhead is electricity and power, which could be dramatically reduced by installing photovoltaic solar panels. Not only will your profits be maximized, but you can also reduce your business’ carbon footprint, enjoy energy independence, and save more money on equipment maintenance. Plus, taking steps to show that you care for the environment make for a good corporate social responsibility campaign!
Photovoltaics for the City
As of 2010, there are nearly 30 “megacities” in the world—these cities are not exactly the richest or the most advanced in the world, but they boast of over 10 million residents. The amount of homes and businesses in such cities is overwhelming—as are the electricity demands of the residents and workers in the city. There are many benefits of using solar power-generated electricity in the city: environmental, social, and economic.
Solar power does not need fuel in order to generate electricity, which means that there is no trace of waste or pollution emitted during the generation process. This also means that the sustainability of the city can be significantly improved by using photovoltaic technology. Solar panels can also be mounted on roofs, the sides of buildings, or basically any place where the panels can collect sunlight, without impact on the use of land or the ecology of certain city areas.
Photovoltaics can also increase employment in the city, and add to the business opportunities in the area. Investing in photovoltaic systems might feel like it is costly in the beginning, but would be a worthwhile investment for both individuals and businesses in the long run.
Photovoltaics in Sport
Applying the technology of photovoltaics in the world of sport is not a quick leap, but rest assured that clean and sustainable energy is being embraced by this field. In recent times we’ve seen the emergence of for uses in sport and everyday life. These items are a clever way to extend the life of popular items such as smartphones, GPS equipment and any battery operated chargeable item. By simply using the sun you can effectively charge any of these devices. These items could prove to be essential emergency backups especially when hiking.
Many new stadiums—especially those ones built for much awaited sporting events such as the Summer Olympics and the FIFA World Cup—are using photovoltaic technology to power the whole structure. Aside from dramatically reducing the operating costs of the stadiums, the move toward more sustainable and renewable energies in the world of sports is adding another integral value to its credo: the conscious use of clean energy for a better future.
The Pros and Cons of Photovoltaics
The technology of photovoltaics has long proven to be something that really works. The seemingly complicated process of converting solar radiation into electric current is an easily replicable, sustainable, and cost-efficient way of generating electricity to power our modern world. Like any other kind of technology available for mankind to use, there are pros and cons to photovoltaics. Here are a few of them.
The Benefits of Photovoltaic Systems
As mentioned earlier, there are plenty of benefits involved with the use of photovoltaic systems. One of the most important features of solar power is that it is renewable, and derived from a source that is widely distributed across the planet. Sunlight is abundant, and each new day is another chance to harvest its powers. Energy experts and scientists are optimistic that sunlight could be the primary energy source of the planet in the near future.
Another major benefit of solar electricity is that it does not emit pollution while generating power. For centuries, mankind has relied on the use of fossil fuels to power their homes and industries, and this history of use has taken its toll on the environment. Pollution from power generation is one of the most dangerous threats our planet is facing–and this pollution is something that solar power can help us avoid. Research is also underway to make photovoltaic technology friendlier to the planet by producing easily recyclable components to cells, arrays, and modules.
Photovoltaic systems also fare well in terms of longevity—studies and tests show that photovoltaic installations can be operated for a century, or even more. There is no need for expensive maintenance or intervention after the system has been properly installed. Thus, operating expenses are kept low and there are not much overhead expenses involved in the use of photovoltaic systems. Photovoltaics are also very reliable, even in the face of bad weather and harsh conditions.
In the future, researchers and energy experts are hoping that more funds be directed toward improving photovoltaic technology, where there is much to improve despite the already impressive features of the technology. Innovations in pohotovoltaics can involve using it with other sustainable energy sources like wind and hydro systems, or improving the materials used for the technology.
The Disadvantages of Photovoltaic Systems
At present, installing a photovoltaic system that can supply the electricity needs of a whole city can be very expensive—so far, the cost-efficiency of the technology is only limited to comparatively smaller installations. However, most analysts are optimistic that the costs will be significantly reduced in the future once more systems are installed and deployed in different parts of the world.
One of the major weaknesses of photovoltaic systems is that it wholly depends on the availability of sunlight. Areas that often experience cloudy skies and shorter daytime are not exactly the best places to install photovoltaic systems in. The power that photovoltaic systems produce is often stored in batteries, which could complicate the simple and efficient process of converting sunlight into electricity. The batteries will need maintenance and intervention during the course of operation, and replacements might come at a bit of a cost.
Photovoltaics and the Future
The science behind photovoltaics was discovered almost 200 years ago, by a (then young) French physicist named A. E. Becquerel. The little experiment Becquerel performed in his father’s laboratory served as the backbone of one of the most exciting technologies in clean and sustainable energy. Photovoltaics is a relatively simple technology—a material surface should be treated with a specific kind of chemical to allow it to absorb solar radiation and turn the radiation into electric currents and voltage.
Photovoltaic technology is a great way to power the modern world—the electricity generated from the power of the sun is clean, renewable, and reliable. The technology that we have developed to facilitate the process of electricity generation is quiet, does not require frequent or expensive maintenance, and can be easily installed in homes, businesses, or public buildings.
However, despite the relative simplicity and numerous benefits of photovoltaic systems, the funds that are being diverted into deeper and wider research is not enough to produce groundbreaking work in the last few decades. Looking at the bright side, this means that there is so much more to discover and improve about the current photovoltaic technology that we are using,
One of the most exciting innovations in the world of photovoltacis is the future generation solar cells, which are specifically developed to address the Shockley-Queisser limit, which dictates the 31 to 41 percent power efficiency for many types of solar cells. Improving solar cells—the core of the technology—will include the use of biomimetics and polymer cells, solar thermal technologies, and hot carrier cells, among others. Improving the materials of solar cells will expand the number of applications for the technology, and even integrate photovoltaic cells into clothing, which would then generate power for wireless devices.
Many industries are shifting to the use of organic materials in their products and services, and the photovoltaics field is no exception. Some energy experts believe that the next big thing in the field of photovoltaics is the use of organic materials, which will take the eco-friendly aspect of the technology to another level. Organic photovoltaics will use solar cells made of carbon-based polymers, which are less expensive and friendlier to the environment. While organic solar cells are not as efficient as those made of crystalline materials (or even gemstones), researchers believe that they will be more useful, since they are more cost-efficient to produce and install.
Research is also underway for the production of cheaper solar collectors—the company CoolEarth is studying the viability of inflatable solar collectors, which can be made of cheaper materials and can be installed on wires instead of costly frames. The maintenance of these inflatable collectors (basically, solar balloons) is even cheaper—damages can be repaired by tape, and damaged units can easily be replaced in just fifteen minutes.
As technology and the means for production advance, the cheaper photovoltaics will be. With more and more people interested and invested in the many benefits and advantages of photovoltaics, we can be certain that the future does look bright for solar power generation.