Harnessing the Sun

Living with the sun is nothing new. Solar technology has been used by man for practical purposes since time immemorial. Legend has it that Greek soldiers used polished shields that reflect sunlight to blind their enemies. Romans have built the Pantheon around the sun, using daylighting techniques to provide natural interior illumination and to showcase the beauty of sunshine.

Global energy consumption drastically increased during the 19th century Industrial Revolution. The growth of factories necessitated the use of more powerful sources of energy such as wood and coal. Thus, energy sources rapidly transitioned from solar-based to fossil fuels. The oil embargo and energy crisis in recent decades led world leaders to rethink their energy policies and focus on developing alternative energy With the outpouring of environmental awareness, vast possibilities of solar power are once again being discovered and untapped.

Being able to utilize the sun to generate electricity is one of man’s greatest achievements. Though prehistoric man knew how to use bits of glass to reflect the sun’s rays to start a fire, the technology to directly turn sunlight into electricity is only a few decades old. Solar power is currently being used in agriculture, chemical and metal industries and in households. The use of evaporation ponds to get salt from sea water is one of its older applications. Single solar cells are used to power on calculators, wrist watches and highway signs. Solar water heaters heat swimming pools, greenhouses control the use of light to grow crops, solar distillation provides potable water to households, and solar energy provides the high temperature needed for metal smelting and chemical production.

How solar energy works

Solar energy – the energy from the sun in the form of heat or light – is being harnessed by technology that controls the use of the sun’s energy. Sunlight is converted into electricity by photovoltaics, a system which produces a reliable and non-polluting form of energy without using any fossil fuels.

Photovoltaic cells directly convert sunlight into electricity. Also known as solar panels, these cells are made up of the element silicon, the second most abundant material on earth. However, due to its difficulty to make, solar panels can still be quite expensive. To make the panels, silicon is heated to extremely high temperatures and chemicals such as boron and phosphorus are added. This makes the silicon atoms unstable so that when sunlight hits the solar panel, the modified silicon’s electrons are jarred, thus causing electricity to flow and provide electric power. When sunlight hits a solar panel, the electrons in the silicon start to move. This movement causes energy to flow through wires built inside the panels, producing electricity.

Pros and cons of solar energy

The biggest advantage of solar energy is that it is non-polluting. Unlike oil and fossil fuels, solar energy is a renewable resource. Solar cells are also easy to install and require very little maintenance. Although investing in solar panels can be a bit pricey at first, reduced electricity bills will definitely still save money in the long run. After all, the sun is ours for free.

The main disadvantage of solar energy is the restrictive financial cost of investment in solar panels. Installation also requires a large area, thus making solar power inefficient in places where space is expensive and limited. However, as newer technologies in solar energy develop, prices have dropped and more efficient styles are being produced. This is indeed very good news, as solar energy is increasingly becoming popular and available to many. Hopefully, this will encourage people to use solar energy for their electricity needs – not only because it is a hot, new trend but because it is right.

Thanks to the wonderful science of photovoltaics – the field of study related to the technology and application of solar cells to produce energy – many products can now be powered by the sun. And it all just starts with a solar cell, the basic device that you need to convert solar energy into usable electricity.

In theory, how solar cells work is really quite simple. Tiny particles called photons in sunlight are absorbed by the solar cell which is made from silicon (a semiconductor).

As sunlight hits the cell, the electrons inside the solar panels get ‘excited’ and start to move around, until they are knocked off from their atoms. They then flow through the silicon panel, creating electricity. The solar-generated energy can now be put to work – from lighting a bulb, heating a pool, cooling your house, or it can be stored in a battery for future use.

Now that you know the science and the principle behind the solar cells, perhaps you would like to give it a shot by making one in your very own home.

Using materials easily bought from the hardware store (i.e. a copper sheet and a simple micro-ammeter) and borrowing things from your very own kitchen (such as an electric stove and table salt), you can make your very own representation of a solar cell. However, do not plan on covering your entire roof with this homemade variety just yet. While it may be effective in illustrating the scientific concept of photovoltaics, it can probably power no more than a single light bulb.

]]> http://www.solar-energy.com/?feed=rss2&p=64 http://www.solar-energy.com/?p=62 http://www.solar-energy.com/?p=62#comments Fri, 15 Aug 2008 09:16:07 +0000 solar http://www.solar-energy.com/?p=62 What are solar panels?

So you have heard the buzz about the benefits of solar energy and fancy reducing your electricity bills , whilst also doing your bit for the environment. Well now is definitely a good time to give the sun a shot, but where do you get started? Well firstly you need to get your very own solar panels.

Yes, but what are they? Well solar panels are devices that catch the sun’s rays, and manage to convert this light into electricity. A group of solar cells (similar to the one that runs your solar-powered wristwatch or calculator) are laid out over a large space to capture sunlight.
The basic principle is: the more cells hit by light, the more electricity is produced. Straightforward and uncomplicated, solar panels immediately convert light and heat into energy which then powers your home’s appliances.

How do solar panels work?

Whether it’s the single solar cell found in your wristwatch or the multitude of solar panels atop your roof, solar energy is generated in essentially the same way. Through the principles of photovoltaics, heat and light from the sun is transformed into usable energy and electricity to power appliances, heat water and even to make a car run.

A solar panel is basically a sandwich made of two layers of silicon. When photons of sunlight hit the panel, the electrons in the silicon panel get ‘excited’ and move around, until they eventually get knocked off their place and move through the attached current and connecting wires. Thus, electricity is generated as the current finally enters a battery or power generation device.

Types of solar panels

There are three main types of solar panels, all of which are based on silicon as a semiconductor. The only difference between these three types is the form that the silicon is in. However, this variation causes differences in efficiency, size and price. So it’s important to know the types of solar panels when it comes to choosing the right one for you.

Monocrystalline solar panels are made from thin silicon layers sliced from large crystals. These relatively larger cells are laid out side-by-side in a panel. This type is perfect for maximizing the solar energy gathered in a limited space, or when you want to limit the size of your solar panel installations for aesthetic reasons. On the downside, production costs for growing large silicon crystals is quite high, which means this type of solar panel is a little more expensive than the other kinds.

On the other hand, polycrystalline solar panels are cheaper than its monocrystalline counterpart. It takes a less-controlled environment, and thus lower production cost, to create silicone in polycrystalline form. Although less efficient in terms of pound-per-watt calculations, polycrystalline cells are a good-enough alternative and are priced much more competitively.

Contrary to the previous two types of solar panels that come in the form of a grid or crystal lattice, amorphous silicon panels are made of very thin flexible layers. This type of panel can bend over roofs and can even be rolled up and put away when not needed. Though still not as efficient as the monocrystalline type, amorphous solar panels can still do the job quite well. Once mass production of the amorphous type is possible, its price could go substantially lower.

Are solar panels expensive?

Solar panels can be quite an investment, but the good news is they can pay themselves off in a few years. The monocrystalline kind is the most expensive and also has the highest lifespan of over 25 years. However, for a typical household’s energy requirements, polycrystalline panels get the job done. You should expect to shell out quite a hefty sum to solar-power your house. However, with the reduction in your electricity bill and the fact that you are helping the environment in the process, going solar is definitely a good idea. It is something those expensive Italian mosaic tiles or a kitchen renovation can’t do.

Solar power is simply the utilization of the sun’s radiation into heat or electricity. And in recent years, the use of solar power as an alternative source of energy has become more popular than ever. With our increased care in the environment coupled with the rising prices and dwindling supply of fossil fuel, the industry behind solar power is growing faster than ever. Technology has also made the sun useful in more ways than we thought possible.

How does solar power work?

The process involved is quite simple. Solar energy works by converting the sun’s rays into heat using solar thermal collectors for heating water, and solar panels to supply power to the appliances in a home. With solar collectors, heat is captured from the sun in glass tubes, which then heat the water. With solar panels, radiation is retrieved and collected from the sun.
When the sun’s rays hit the solar panels, they are absorbed by semiconductors such as silicon (the material solar panels are typically made of.) The process causes electrons to be knocked off from their atoms, allowing them to flow through the material, thus generating electricity.

Solar power homes

If you are looking for a way to reduce your electricity bill while saving the world at the same time, powering your home with solar energy just might be the answer. A solar powered home is simply one that uses a photovoltaic solar power system to supply power to the home. Normally, the method involves placing the system on the roof facing the south to maximize the exposure to daylight. Most of the time, the total energy requirement of a home can be supplied using the photovoltaic structure though most owners prefer to supplement conventional electricity with solar power.

Solar powered homes hold several advantages. Not only do you help conserve the planet’s dwindling supply of fossil fuel and natural gas, your wallet also benefits from a reduction in energy costs. Despite the substantial initial investment, going solar will definitely give you the best deal for your dollars in the long run. This is something a kitchen remodeling or a plasma screen just won’t do.

Solar powered cars

With the restrictively high price of gasoline and the toxic emissions automobiles churn out into the atmosphere, even cars are going solar. Solar powered cars are not a thing of the future. In fact, they just might go mainstream in the next few years. So just how does a powerful car engine run on sunlight? Simple. A barrage of solar cells transform the sun’s heat and light directly into electrical energy which powers the car. Solar powered cars are often made with unbelievably curious shapes as designers want to lessen the drag factor, maximize full exposure to the sun, decrease the weight, while maintaining safety and function.

Government and automobile manufacturers have realized the potential of solar cars and hold races each year to create the best and fastest design. Usually entered by university students, racers and developers show-off their engineering and design skills by building and running their very own solar car.

Solar power kits

And now, wiring your house for solar power comes in a box. And all you need to do is purchase a solar panel kit. Everything you need to get started is right here: solar panels, pre-wired modules, a battery pack and the all-important instructions. Unleash the handyman in you and install your own solar panels without needing to hire expensive professionals and electricians. Though not quite made for beginners, a kit is great for the experienced do-it-yourselfers. Not only does powering your home with solar energy drastically reduce your household’s electricity bill, a solar kit becomes incredibly handy in the event of power failures.

Solar energy is free of charge and the supply is infinite. Our planet’s greatest heat source leaves much to be untapped. Whether you want to save some dollars or do something for the environment, now just might be the time to make the switch to solar.

The good news is, we have come up with promising alternative sources of energy. By harnessing the infinite resources of the sun, the wind, water and the tides, we have come up with non-perishable and non-polluting substitutes for fossil fuel. Furthermore, the same chemical reaction that produces the sun’s massive energy, nuclear fusion has become a real, viable and very powerful alternative. Although all of these measures are not entirely devoid of negative consequences, they are considered to be far less damaging than those sustained by fossil fuels.

Solar Energy

In sunny Florida and sun-drenched California, houses gleam with big shiny panels on the roofs. These homes are part of the growing number of American families whose energy needs are being met by solar power.

Harnessing the sun’s energy is relatively simple technology. Solar cells, typically referred to as “photovoltaic” cells, transform sunlight directly into electricity. The electricity generated from solar cells can be used to power practically all gadgets – from simple calculators and wristwatches to central heating systems and swimming pools.

Why switch to solar? First of all, the sun’s energy supply is unlimited. In fact, the sun provides us with enough solar energy in a day to meet our worldwide consumption needs for a year. To join this silent revolution you will need the latest solar panels. Although solar panels can be quite an expensive investment, the reduction of your household’s energy requirements translates into hefty savings in the long run. And if that’s not enough, there’s also the fact that you have done your bit for our planet’s growing environmental problem.

Nuclear Energy

Stars are products of a nuclear reaction, the process wherein two nuclei collide. This causes a release of immense energy, enabling these balls of fire to shine for billions of years. And the good news is, there is a way to use this massively powerful chemical reaction in our very own planet.

This highly controversial technology also shows the most potential. Immense energy is produced through nuclear reaction and if harnessed safely and effectively, nuclear energy could solve most of the world’s fossil fuel shortage. Currently, nuclear energy is produced using the nuclear fission theory, where the nuclei of atoms are split to release energy. However, this technology, as unfortunately demonstrated by the Chernobyl explosion, has proven to be very dangerous and prone to leaks and emission of toxic waste.

A much safer option lies with fusion power. In nuclear fusion, two atomic nuclei are joined together to form a heavier nucleus, thus releasing huge amounts of energy in the process. Though still in its early stages of development, nuclear fusion might just be the answer to our enormous demand for alternative energy.

Geothermal Energy

The mighty Romans were one of the first people to harness and enjoy the beauty of geothermal energy. Men have used hot springs for bathing, cooking food and removing feathers and skin from game. Fast forward several thousand years and the ancient hot springs are now today’s urbane health spas and heated swimming pools. Still, hot water and steam are used for far more than rest and relaxation. In fact, they can be channeled to generate electricity.

Geothermal energy is heat derived from the earth’s core. Wide-scale use of geothermal energy is obtained by drilling wells into reservoirs to enable hot water from the earth’s core to be processed and converted into usable electricity. Since it doesn’t entail denudation of forests and damming of rivers, geothermal energy is an affordable and sustainable answer to our acute dependence on fossil fuels.

Fuel cells

Experts predict that fuel cell technology will become one of the world’s most widely used alternative sources of environmental-friendly energy. This technology has shown such potential that governments in various countries have shown their support for research and development of fuel cells.

Basically, a fuel cell is similar to a battery in the sense that it converts chemicals to energy through a device. Powered by hydrogen and oxygen, a fuel cell produces heat and electricity infinitely as it does not require recharging. Since fuel cells rely on chemistry and not combustion, there is no polluting emissions or toxic wastes. Moreover, since hydrogen is a renewable resource, fuel cells are a cleaner and more efficient alternative to fossil fuels.

With global warming becoming increasingly hard to ignore, the challenge is to seek out better alternatives to fossil fuel. With oil prices rising and the supply of wood and coal dwindling, now is definitely the time to make the switch.

As we all know, fossil fuels have become some of the major culprits of the earth’s wear and tear. The burning of coal, oil and natural gas contribute largely to carbon dioxide emissions.

Half of these emissions are absorbed by the planet’s vegetation, soil and oceans. The leftovers remain in the atmosphere for centuries or even longer.

With all the disadvantages that fossil fuels pose on humans and the environment, the call for alternative sources is set to become louder.

Some of the alternative energy sources that are perceived to help restore the environment (or at least not be as damaging) include tidal energy, hydroelectric energy, wind energy and biofuels.

Tidal energy

Tidal energy refers to the rising and falling of sea levels that can be used to generate electricity. Typically, tidal power can be obtained by building a dam across the opening to a tidal basin. The dam is built with a sluice that is opened to let the tide flow into the basin. When the sluice is closed and the sea level falls, conventional hydropower technologies can be utilized to produce electricity from the elevated water in the tidal basin.

With tidal energy, there is no traditional burning of fuel involved. As a result, it produces no greenhouse gases or other wastes. One disadvantage of tidal energy is that it can only be harnessed in areas with significant water level changes.

Also, tidal energy systems can pose environmental effects on tidal basins as they lessen tidal flow and cause silt buildup.

Hydroelectric energy

Hydroelectric power is the largest source of renewable power in the world and provides one-fifth of the world’s electricity.

It is a renewable energy source that depends on the hydrologic cycle of water, which involves evaporation, precipitation and the flow of water as a result of gravity.

Technically, converting water into electricity involves the use of a device called a hydraulic turbine that turns flowing water into mechanical energy, which is then converted to electricity with the use of a hydroelectric generator.

Hydroelectric energy doesn’t cause pollution since producing it doesn’t create heat or toxic gases. It also doesn’t involve the use of fuel and requires low operating and maintenance costs.

While it does not cause pollution, it has certain impacts on the environment such as loss of wildlife habitat and destruction of ecosystems.

Wind energy

Since ancient times, people have relied on the wind’s energy. More than 5,000 years ago, the ancient Egyptians used the wind to sail ships. Others built windmills to grind wheat and other grains. Today, the wind is used to generate electricity.

Wind energy is non-polluting, sustainable and available in infinite quantities. Best of all, nature’s gift is ours for free. For these reasons, great gusts of wind are harnessed into the more usable mechanical energy and electricity. Though wind is still not a primary source of energy, it has served almost two million households in the United States in the past few years.

Wind energy is a clean fuel, resulting in zero byproducts or polluting effects. While wind generators do not pollute the air, they are quite noisy and have been known to have a negative effect on wild birds. Although the sight of gleaming blades turning and twisting in the air can be beautiful for the occasional tourists, they are considered an eyesore for many as they destroy the beauty of natural scenic landscapes. Nevertheless, a terrain decked with windmills is definitely a much prettier sight than the traditional smoke-emitting power plants.

Biofuels

Did you know that GM passenger vehicles and the Mercedes Benz E Class have something in common? They are all capable of running on biofuels, which have been regarded by many as better alternatives to gasoline.

In a time of rapidly increasing prices at the fuel tank, it might be time to make the switch to biofuels. Also known as agrofuel, this alternative source of energy is derived from renewable resources, such as plants and organic waste as a substitute to fossil fuels. Biofuels have found their main use in the transportation sector, with many automobile manufacturers going green with their new breed of eco-friendly, biofuel-powered cars.

Automobiles are a major contributor to pollution. By looking for alternatives to gasoline environmentalists are hoping to drastically lessen the emission of toxic fumes in the coming years. Biofuels are touted as one of the best alternative energy sources for the transportation sector, as they emit over 50% less greenhouse gas than fossil fuels.

In fact, the use of biofuels has become more popular and widespread all over the world. The rising price of oil coupled with the recent trend of environmental awareness has triggered many to make the switch.

Alternative energy sources show remarkable promise in helping to decrease the amount of toxic substances produced by fossil fuels. Not only do they provide defense against dangerous by-products, they also help safeguard many of the natural resources that we presently depend on as sources of energy.

“Everybody talks about the weather, but nobody does anything about it.”

Mark Twain

2005 was the hottest year ever. In fact, the last few years have been the warmest years on record. Global temperatures are 1.0F warmer than they were a year ago – and the heat is accelerating at a breakneck pace.

Hurricanes and storms have increased in number and intensity over the years. Hurricane Katrina and the Indian Ocean tsunami were not mere coincidences. Meteorologists have reached a consensus that the onslaught of super typhoons and intense tornadoes are brought about by the unnatural changes in the climate. The increased level of pollutants trapped in the earth’s atmosphere is causing global warming, thus making our weather patterns go awry. These natural disasters have caused billions in property damage, as well as the loss of countless lives.

Polar bears are in danger of extinction. We have lost sea ice the size of Texas. Some scientists are predicting that 2040 could be the Artic’s first ice-free summer. All these are signs of global warming and a planet collapsing under the strain of pollution and mismanagement.

Melting polar ice caps. Earlier springs. Rising sea levels. Extinction of species. Coral reefs are dying. Super storms and mega hurricanes. Killer bees. Nature has indeed unleashed its fury. Yet there is still something we can do about it!

Americans account for most of the world’s pollution. This is easily supported by statistics which reveal that although we only account for 5% of the world’s population, we are responsible for 25% of global pollution emissions. These embarrassing figures need to change – and fast.

As an average citizen, there is always something you can do. Switch to a fuel-efficient or eco-friendly vehicle, walk when you can, Carpool. Change your light bulbs from incandescent to fluorescent, Invest in solar panels, support eco-friendly products and establishments, minimize your use of plastic, unplug rarely used appliances, plant a tree. A single person can make a dent. All of us can make a difference.

]]> http://www.solar-energy.com/?feed=rss2&p=54 http://www.solar-energy.com/?p=52 http://www.solar-energy.com/?p=52#comments Fri, 15 Aug 2008 09:04:58 +0000 solar http://www.solar-energy.com/?p=52 The signs that our planet is sending can be ignored no longer. Nature is changing its course. Powerful storms, more intense droughts, warmer weathers, heat waves, gigantic fires and continual melting of the polar ice caps are a constant occurrence and a part of the daily evening news. Experts think these are all signs of global warming - symptoms of an ailing planet in the throes of a coma.

What is global warming?

Many have said that global warming is a problem for future generations. However, its arrival cannot be denied anymore and there is compelling and mounting evidence that it is now taking place.

Here are some of the signs:

• The last 12 years have been recorded as the warmest on record for global surface temperature.
• For the past 50 years, the rate of warming has increased twofold.
• Severe weather events have taken place more regularly in the past 50 years.
• There has been a reported temperature increase of 1-degree Fahrenheit in most of the United States over the past century.

All these point to one of the most serious challenges we as a people have to face.

As the planet gets warmer, there will be noticeable changes in rainfall patterns, a rise in sea levels, and a wide range of impacts on plants, wildlife, and humans.

Global warming is a naturally occurring phenomenon and is even necessary to maintain life on the planet and enable survival. It is responsible for keeping the earth’s temperature at a comfortable level, 60°F to be exact. However, the emission of pollutants into the atmosphere has fast-tracked global warming at alarming levels. Our planet has been growing increasingly warmer by 1°F over the past century and is at its warmest state today than at any other point in the millennium. The notable increase in temperature and the terrifying disturbances in the weather are difficult to deny. Our world is definitely growing hotter.

The signs of global warming have been manifesting themselves for years. Heat waves, rise in sea levels, warming of the poles and melting glaciers have longed warned us of a meteorological calamity that has now arrived. Furthermore, as global warming becomes more frequent, continuous and widespread, recent events are an omen of an impending catastrophe. The spread of disease, earlier onset of spring, plant and animal changes, coral reef bleaching, downpours, fires and droughts are the disastrous effects brought about by the changing climate.

Cause of global warming

Greenhouse gases are naturally released into the atmosphere as part of nature’s innate processes, it is man and his blatant disregard for his environment that is the cause of the unnatural global warming that we experience today.

The main culprit of global warming is the pollutants emitted from the burning of fossil fuel. When coal or oil is burned, they release carbon dioxide and other greenhouse gases into the atmosphere. These toxins trap the sun’s heat, thus causing the earth to heat up. Coal-burning power plants and automobiles are the largest source of carbon dioxide pollution, emitting billions of tons of toxic fumes into our fragile atmosphere each year.

Effects of global warming

As the concentration of greenhouse gases swells, the sun’s heat is trapped in the atmosphere and cannot be released back into space. Trapped sunlight causes temperatures to rise, thus drastically changing climate and altering weather patterns. Nature then behaves uncharacteristically – seasons become shorter, coastal flooding more frequent and storms more severe.

Most alarming of all are the melting of the polar ice caps. This causes sea levels to rise, thus throwing the global ecosystem out of whack. A snowballing effect is certain to ensue – increased temperatures will bring about changes in landscape, thus making it extremely difficult for plants and animals to survive.

Humans are not immune from the devastating effects of global warming. Desertification, or the expansion of deserts, will render large areas of the world uninhabitable. Droughts and floods could create food and water shortages and trigger widespread migration and even war.

Global warming is here and its effects are inevitable. Despite this upsetting news, there is a positive side. Worldwide efforts have been made to find solutions to minimize the effects of global warming such as cutting down energy use, mobilizing renewable resources, and employing alternative sources of energy. Only man’s collective efforts at reversing his own misdoings can recover our planet. It is about time we start to care.

• Solar lights. Outdoor solar garden lights usher in a whole new revolution in lighting and landscaping. Aside from being environmentally friendly, the latest breed of solar lights are now more functional and aesthetically pleasing. Equipped with LED lights, these outdoor solar gadgets last longer and shine brighter. What’s also great about solar lights is that there is no need for wiring to connect to an energy source. Thus, they can be placed and moved around anywhere you want them to fit your lighting needs.
• Solar water heaters. From the one-million gallon pool used in the 1996 Atlanta Olympics to virtually all homes in Israel, India and Greece, solar water heaters are all the rage. What is great about this technology is that manufacturers create different types of heaters to fit all needs, residential or commercial. Solar heaters can either act as the primary source of heat or as a back-up to the conventional electric heater. It’s about time you heat up your bath and swimming pool with solar heaters.
• Solar cookers. Ranging from the simple and homemade to the modern and high-tech. Solar cookers are a useful and eco-friendly alternative to conventional cooking. Perhaps its greatest and most noble purpose yet is humanitarian. Widely used in African villages and refugee camps in Darfur, solar cookers have greatly improved the lives of many people. Women no longer have to leave the safety of their refugee camps to gather firewood and families can save on cooking fuel by going solar.
• Solar cars. Though yet to be available to the general public, the government, scientists and economists recognize that the future of transportation could well be powered by solar cars. Though vehicles can be powered on solar energy alone, the cars of the future would most probably run on a hybrid of solar and traditional gasoline. Still, there is one thing we know for sure: our spending at the fuel pump will definitely be much lower.

So take the road less traveled and make the switch to solar. The key to saving the environment is available at a store near you.