Solar Photovoltaic

There have been many debates around the globe on using solar energy as the means to fuel the economies. However, is it really possible? Before understanding what solar photovoltaic is, let us see the current scenario of our planet.

For thousands of years, animals and plants' remains that were buried in the earth were subjected to very high temperature and pressure. The resultant as known to humans was petroleum and coal. Now, we know what it takes to produce the two main sources of energy, so, can you think of any way to reproduce them so that we can meet the daily requirements? No matter how advance we are or how many improvements we see in our sciences, we can never produce the two main sources of energy.

The reason is clear; we can not wait for thousands of years, we have no means to collect animal and plant residual in such great quantity, we can not subject them to artificial high temperature and pressure and hence, the task is impossible. Furthermore, since we were kids, we have been taught that coal and petroleum are non-renewable sources and also that they are in a limited quantity on earth. So, this implies that sooner or later chances are that we will run out of fuel! Can you imagine the world then? No electricity, petrol, gas etc to do the daily jobs!

Fortunately, the great thinkers of every country, scientists, noticed this fact and hence, started working on methods to find an alternative to combat this problem. One thing that is known to all is that sun is the ultimate source of energy that is renewable in every sense too! So, methods to capture and transform solar energy into other types of energies like electricity and heat were invented. Solar photovoltaic systems can achieve just that.

The basic task of solar photovoltaic is to collect solar energy and then convert it into electric energy. The very name "Photovoltaic" implies the underlying principle as well as its working. solar photovoltaic generally consists of silicon semiconductor cells that are connected to each other. It is covered with glass for providing insulation. The heat energy is an input for solar photovoltaic while electricity is the output. This means that home solar power systems can take off the burden of your power bills and lower it considerably, if you employ such solar photovoltaic systems at your home.

This will result in generating energy on your own from a renewable source. Consider the benefits here. Using solar devices will decrease the consumption of fossil fuels. Furthermore, the countries that depend on others for these fuels will have their own source of energy as solar photovoltaic can be manufactured and used anywhere on this earth. Finally, solar energy is completely free from poisonous or greenhouse gases and residuals. Not only this, you can make use of solar photovoltaic and store electric energy for future usage as well. You don't need to wait for sun rise for doing so. solar photovoltaic therefore, is a great invention that is for everyone alike and very beneficial too!

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Photovoltaic Modules

Skeptics and pessimist knew it all along: Solar photovoltaic modules could not possible be all that simple. Even the most elegant technology is never perfect, so here are a few things to watch out for.

Wattage ratings on photovoltaic modules are given under ideal laboratory conditions at room temperatures. There are two factors which directly affect module performance out in the real world: percentage of full sub, and temperature.
Full Sun

Most of us seldom see 100% of full sun conditions in our locations. If you are not getting full, bright, shadow-free sun, then your photovoltaic output will be reduced. If you are not getting bright enough sun to cast fairly sharp-edged shadows, then you do not have enough sun to harvest much useful electricity.

Temperature

The current from all modules fades somewhat at higher temperatures. This is not an important consideration until ambient temperatures climb above 80 deg.F, which is not uncommon in the sun. The backs of modules should be as well-ventilated as possible. In very hot installations where surplus water is available, sprinklers are sometimes employed to cool the modules. On the positive side of this same issue, all modules increase output at colder temperatures, as in the wintertime when we need all the help we can get. We have seen cases when the modules were producing 30 % to 40% over specs on a clear, cold winter morning with a fresh reflective snow cover and hungry batteries. What this all boils down to is this: Derate your module output by 15% as a general rule of thumb. If you are designing a panel-direct system (where the modules are connected directly to the pump or fan without charge controllers or batteries), derate by 20%, or by 30% for direct applications in a hot climate.

Shadows

Even a tiny amount of shading dramatically affects module output. Electron flow is like water flow. It flows from high voltage to low voltage. Normally the module is high and the battery or load is lower. A shaded portion of the module drops to very low voltage. Electrons from other portions of the module and even from other modules in the array will find it easier to flow into the low voltage shaded area than into the battery.

Maintenance For Photovoltaic modules

It’s almost laughable how easy maintenance is for photovoltaic modules. Having no moving parts makes them practically maintenance-free. Basically, you keep them clean. It if rains irregularly or if the birds visit often, you would be wise to wipe the modules down. Do not hose them of when they’re hot, since uneven thermal shock could theoretically break the glass. Wash them in the morning or evening.

Control Systems

Conventional controls for photovoltaic systems are usually simple. When the battery reaches a full-charge voltage, the charging current can be directed elsewhere, or the circuit opened. Without a load, module voltage rises 5 to 10 volts and stabilizes harmlessly. When the battery voltage drops to a certain set-point, the charging circuit is closed and the modules go back to charging. Most controllers offer a few other whistles and bells like nighttime disconnect, LED indicator lights, etc.

You may be interested to explore more on photovoltaic cells and how do they work.

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Renewable Energies

The existing energy supply picture worldwide, and in many industrialized countries, shows that more than 80% of overall energy consumption involves the use of coal, petroleum and natural gas. Hydroelectric power accounts for the largest share of renewable energies to date. The potentials of renewable energies have not yet been fully exploited worldwide. To do so, it will be necessary to overcome two considerable hurdles. One is that the energy provided by the sun arrives here at a low energy density. It must therefore be “collected” over large areas. For the use of solar energy, this requires greater investments than for the use of fossil energy sources, even considering all investments necessary for air-pollution control and the additional costs by CO2 certificates. The second basic difficulty for the use of renewable energy is the fact that solar and wind energy fluctuate. Moreover, they are hard to store, since neither seasonal heat storage of sufficient quality nor storage for large quantities of electrical energy are technically available.

A central question of future energy supply, and thus also a central question of the further energy research and technical development, is that of storage. Solar and wind energy replace fossil and nuclear energy sources. However, they cannot replace conventional power stations or heat production systems to any considerable degree. They need conventional backup systems, which thus make the use of renewable energies additionally more expensive. The price for hard coal would have to triple, for example, for the use of wind power to become competitive from a strictly business-management point of view. The use of sunlight for electric-power generation by means of photovoltaics cannot become competitive by means of price rises for energy at today’s costs of photovoltaic facilities. What is needed here is a technological breakthrough leading to a considerable reduction in the cost of photovoltaics, in order to make the broad-scale introduction of this energy-supply technology possible. Find out more interesting information on how solar photovoltaic and photovoltaic systems can do for you and your family.

Hydroelectric power is permanently available at larger rivers; biomass is storable. Both energy sources have therefore found their way into the existing worldwide energy supply picture, or will do so easily in the future.

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