Sunday, July 18, 2010

Green Hotels Use Solar Hot Water


More and more commercial operations are turning to renewable energy to green their practices to both save money and the environment. In fact, green hotels use solar hot water to significantly defray operating costs and energy usage.
We’ve written about solar hot water systems incorporated into breweries and dairies – both of which have high hot water demands. It shouldn’t be surprising that hotels and resorts that turn to solar hot water can really cut down on energy demands.
Consider that one of the largest components of hotel operating costs is hot water. Not only is it used by guests to take showers and shave, but significant amounts are demanded each and every day to wash towels and other linens, clean guest rooms and more.

Instead of relying on electricity, natural gas or oil, green hotels can now use solar hot water to maintain profit margins and avoid passing on energy cost increases to their guests. In fact, many properties can expect to save thousands of dollars each year as a result of installing solar hot water.
One company, SunMaxx, has a super solar hot water system for both residential and commercial use. In fact, they can help you develop a solar system to meet the needs of a hotel or resort, including pool and spa heating.
According to its website, a SunMaxx Solar Hot Water System can be used for:
Domestic Hot Water (laundry, cleaning, showers)
Solar Radiant Space Heating
In floor radiant heating
Baseboard radiant heating
Forced hot air heating
Solar Central Cooling / AC Systems
Solar Pool & Spa Heating
Snow / Ice Melting Applications
Sidewalks
Driveways
Parking Lots
Common Public Location

How do Solar Panels Work?


Whether on a solar-powered calculator or an international space station, solar panels generate electricity using the same principles of electronics as chemical batteries or standard electrical outlets. With solar panels, it's all about the free flow of electrons through a circuit.

To understand how solar panels generate electrical power, it might help to take a quick trip back to high school chemistry class. The basic element of solar panels is the same element that helped create the computer revolution -- pure silicon. When silicon is stripped of all impurities, it makes a ideal neutral platform for the transmission of electrons. Silicon also has some atomic-level properties which make it even more attractive for the creation of solar panels.

Silicon atoms have room for eight electrons in their outer bands, but only carry four in their natural state. This means there is room for four more electrons. If one silicon atom contacts another silicon atom, each receives the other atom's four electrons. This creates a strong bond, but there is no positive or negative charge because the eight electrons satisfy the atoms' needs. Silicon atoms can combine for years to result in a large piece of pure silicon. This material is used to form the plates of solar panels.

Here's where science enters the picture. Two plates of pure silicon would not generate electricity in solar panels, because they have no positive or negative charge. Solar panels are created by combining silicon with other elements that do have positive or negative charges.

Phosphorus, for example, has five electrons to offer to other atoms. If silicon and phosphorus are combined chemically, the result is a stable eight electrons with an additional free electron along for the ride. It can\'t leave, because it is bonded to the other phosphorus atoms, but it isn\'t needed by the silicon. Therefore, this new silicon/phosphorus plate is considered to be negatively charged.

In order for electricity to flow, a positive charge must also be created. This is achieved in solar panels by combining silicon with an element such as boron, which only has three electrons to offer. A silicon/boron plate still has one spot left for another electron. This means the plate has a positive charge. The two plates are sandwiched together in solar panels, with conductive wires running between them.

With the two plates in place, it's now time to bring in the 'solar' aspect of solar panels. Natural sunlight sends out many different particles of energy, but the one we're most interested in is called a photon. A photon essentially acts like a moving hammer. When the negative plates of solar cells are pointed at a proper angle to the sun, photons bombard the silicon/phosphorus atoms.

Eventually, the 9th electron, which wants to be free anyway, is knocked off the outer ring. This electron doesn't remain free for long, since the positive silicon/boron plate draws it into the open spot on its own outer band. As the sun's photons break off more electrons, electricity is generated. The electricity generated by one solar cell is not very impressive, but when all of the conductive wires draw the free electrons away from the plates, there is enough electricity to power low amperage motors or other electronics. Whatever electrons are not used or lost to the air are returned to the negative plate and the entire process begins again.

One of the main problems with using solar panels is the small amount of electricity they generate compared to their size. A calculator might only require a single solar cell, but a solar-powered car would require several thousand. If the angle of the solar panels is changed even slightly, the efficiency can drop 50 percent.

Some power from solar panels can be stored in chemical batteries, but there usually isn't much excess power in the first place. The same sunlight that provides photons also provides more destructive ultraviolet and infrared waves, which eventually cause the panels to degrade physically. The panels must also be exposed to destructive weather elements, which can also seriously affect efficiency.

Many sources also refer to solar panels as photovoltaic cells, which references the importance of light (photos) in the generation of electrical voltage. The challenge for future scientists will be to create more efficient solar panels are small enough for practical applications and powerful enough to create excess energy for times when sunlight is not available.

Monday, July 5, 2010

Solar energy changing lives in remote,backward Tharparkar region


Environment-friendly solar energy has changed the lives of several hundred households in Tharparkar, which remains one of the most backward regions of the country.

The Alternate Energy Development Board, Pakistan Poverty Alleviation Fund and Thardeep Rural Development Programme ñ a non-governmental organisation ñ have joined hands to launch the solar energy project in this arid region at a time when the country faces massive electricity shortage.

In a vast desert region like Tharparkar, where temperature hit a peak of 30-35 degrees Celsius even in winters and touches a high of over 50 degrees Celsius during summers, the scorching rays of sun are usually seen as a bane.

But for the first time, this immeasurable resource is being utilised like any other modern place of the world.

Solar energy is not just providing electricity to the mud-and-straw houses of remote villages, but also helps irrigate small patches of land.

“The electricity has changed our lives,” said Khanno, a 45-year-old farmer, who like most residents of this place uses only one name. “Electricity has extended our day. Now my children can study even after the sunset.”

The solar energy project, launched two years ago, has so far provided electricity to 16 villages at a cost of more than Rs100 million, including the villages of Kasbo, Rarko, Wadhanjowadhio and Oanjowadhio ñ all in Tharparkar district.

Riaz Rajar, an official of Thardeep Rural Development Programme, said that one panel costs around Rs700,000 to Rs800,000.

"We install at least eight such panels in a village, which is a one time investment," he said. "They generate enough electricity to illuminate 20 to 30 houses."

“Pakistan Poverty Alleviation Fund contributes 80 per cent of the funds and the remaining 20 per cent is raised by the local community,” Rajar said.

He said that electricity-run power pumps help pull water from 50 to 150 feet below the surface.

“Apart from drinking, this water is also used for irrigation through drip technique to save wastage and conserve this precious natural resource, which is scarce in this region.”

Scarcity of water in Tharparkar, bordering the Great Indian Desert, impacts the entire population, especially women, who had to walk miles to fetch two buckets of water from the wells.

But electric pumps have made their life easy.

Now solar energy is being used to pull water, which is stored in cement tanks.

Khanno, the farmer, said that thanks to electricity he now manages to cultivate onions and tomatoes on his two acres of once barren land.

According to SciDev, a London-based non-profit organisation, there is no shortage of solar energy across the world. Almost all the developing countries have enormous solar power potential, it said in a report.

Solar energy changing lives in remote,backward Tharparkar region

SOLAR TECHNOLOGY


The Solar Energy Technologies Program focuses on developing cost-effective solar energy technologies that have the greatest potential to benefit the nation and the world. A growing solar industry also stimulates our economy by creating jobs in solar manufacturing and installation.
Photovoltaics

The Photovoltaics subprogram aggressively funds a diverse set of PV technologies that have potential in many markets that will help solar electricity achieve grid parity.
Concentrating Solar Power

The Concentrating Solar Power subprogram is making CSP competitive in the intermediate power market and developing advanced technologies that will reduce system and storage costs through partnerships with solar companies and universities and national laboratories.
Systems Integration

The Systems Integration subprogram addresses the technical barriers to wide-scale deployment of solar technologies on the grid by funding solar companies to develop smarter technologies, supporting testing and demonstration at national laboratories and in the field, developing new codes and standards, and removing economic barriers.
Market Transformation

The Market Transformation subprogram works with cities, states, utilities, and other partners to address barriers to the widespread adoption of solar technologies and reduce the non-hardware costs associated with installation.

Photovoltaics


he U.S. Department of Energy works to provide clean, reliable, affordable solar electricity for the nation through its research programs in photovoltaic (PV) energy systems. The following pages explain the "how's" and "why's" of PV. Whether you are a student, builder, consumer, engineer, or researcher, there is something here for you.

Photovoltaic technology makes use of the abundant energy in the sun, and it has little impact on our environment. Photovoltaics can be used in a wide range of products, from small consumer items to large commercial solar electric systems.

Our goal is to ensure that photovoltaic energy systems make an important contribution to the energy needs of our nation and the world. In these pages, you will learn about DOE's R&D in photovoltaic energy systems.

Advancement in Solar Energy Technology


The atmosphere, oceans and land mass of the Earth absorbs enough energy from the sun in one hour to power the entire planet for one year. Surely we are clever enough to capture some of this magnificent force and use it to fuel our environment.
Solar energy and its use can be divided into two areas. Those are static or passive solar energy collection and dynamic, or perhaps better termed, kinetic solar energy collection and use.
An example of passive solar energy collection would be building a house so that the windows face the morning sun in colder climates. An even more rudimentary example would be that of an alligator sunning himself on the edge of the water. In both cases the sun’s energy is simply absorbed for warmth. And the simplest use of solar energy is as the very daylight we walk about in. Our Earth automatically uses the power of the sun in millions of ways. Not the least of which is photosynthesis by plants for production of oxygen for our atmosphere. Ours is an inherently rechargeable renewable world, provided we use our resources such as solar energy wisely.
To that end, we must examine dynamic solar energy collection for the production of warmth and light.
When you walk though almost any shopping mall built in the last twenty years you will probably notice a flood of bright natural light all around you. Most large malls and department stores are built with double paned insulated windows that allow light to enter yet keep heating or cooling locked inside. But what happens when the sun follows its arc away from those windows? Active solar lighting can use mirrors that track with the sun’s movement and then reflect light into fiber optic cable that can carry that light into any part of our same department store.

We can create transfer warmth through various forms of solar thermal energy. Since the 1950s it has not been uncommon to see simple glass paned boxes filled with copper pipes used to help heat water for swimming pools and boilers. These low temperature collectors are fine for space heating but there are far more effective ways to heat water with the sun’s rays and put that water to work.
High temperature parabolic shaped mirrors can heat water to far greater temperatures than made possible by our simple rooftop hot boxes. In fact bowl and trough type mirrors can boil water to steam which in turn uses a turbine to generate electricity for heating, air conditioning and general power supply. When properly applied, this concentrated solar power can supply 50% of the power needs for a modern factory. Concentrated Solar Power is one half of our method for creating electricity from the sun’s radiant energy.

he most commonly thought of use and form of solar energy conversion is that of relying upon solar voltaic cells. These solar cells are also called photovoltaic. First developed in the 1880s, photovoltaic cells rely upon the electronic reaction of certain key elements to the Sun’s rays so as to produce a tapable flow of electrons that are in turned used to create current flow. In short photovoltaic cells turn sunlight into energy. And lest we think we are so clever for figuring out how to do this, consider that plants have been turning sunlight into energy for millions of years.
Advances in the development of photovoltaic cells have increased drastically since the oil shortages of the 1970s. This is primarily due to development of silicon technologies. Crystalline silicon cells when working in conjunction with CSP (concentrated solar power) as supplied by parabolic mirrors have improved output from Photovoltaic cells by a factor of 50 since their more basic development in 1954. Increases in demand and subsequent increases in production have lowered the price of solar cells to the point that they are now almost competitive with wind power technology and like their low emissions wind counterparts are far less costly than nuclear power.
Development, deployment and economics

Solar Electric power as supplied by huge banks of photovoltaic cells is providing billions of watts of power throughout the world.

Thin film solar cells


The high cost of crystalline silicon wafers (they make up 40-50% of the cost of a finished module) has led the industry to look at cheaper materials to make solar cells.

The selected materials are all strong light absorbers and only need to be about 1micron thick, so materials costs are significantly reduced. The most common materials are amorphous silicon (a-Si, still silicon, but in a different form), or the polycrystalline materials: cadmium telluride (CdTe) and copper indium (gallium) diselenide (CIS or CIGS).

Each of these three is amenable to large area deposition (on to substrates of about 1 meter dimensions) and hence high volume manufacturing. The thin film semiconductor layers are deposited on to either coated glass or stainless steel sheet.

The semiconductor junctions are formed in different ways, either as a p-i-n device in amorphous silicon, or as a hetero-junction (e.g. with a thin cadmium sulphide layer) for CdTe and CIS. A transparent conducting oxide layer (such as tin oxide) forms the front electrical contact of the cell, and a metal layer forms the rear contact.

Thin film technologies are all complex. They have taken at least twenty years, supported in some cases by major corporations, to get from the stage of promising research (about 8% efficiency at 1cm2 scale) to the first manufacturing plants producing early product.

Amorphous silicon is the most well developed of the thin film technologies. In its simplest form, the cell structure has a single sequence of p-i-n layers. Such cells suffer from significant degradation in their power output (in the range 15-35%) when exposed to the sun.

The mechanism of degradation is called the Staebler-Wronski Effect, after its discoverers. Better stability requires the use of a thinner layers in order to increase the electric field strength across the material. However, this reduces light absorption and hence cell efficiency.

This has led the industry to develop tandem and even triple layer devices that contain p-i-n cells stacked one on top of the other. In the cell at the base of the structure, the a-Si is sometimes alloyed with germanium to reduce its band gap and further improve light absorption. All this added complexity has a downside though; the processes are more complex and process yields are likely to be lower.

In order to build up a practically useful voltage from thin film cells, their manufacture usually includes a laser scribing sequence that enables the front and back of adjacent cells to be directly interconnected in series, with no need for further solder connection between cells.

As before, thin film cells are laminated to produce a weather resistant and environmentally robust module. Although they are less efficient (production modules range from 5 to 8%), thin films are potentially cheaper than c-Si because of their lower materials costs and larger substrate size.

However, some thin film materials have shown degradation of performance over time and stabilized efficiencies can be 15-35% lower than initial values. Many thin film technologies have demonstrated best cell efficiencies at research scale above 13%, and best prototype module efficiencies above 10%. The technology that is most successful in achieving low manufacturing costs in the long run is likely to be the one that can deliver the highest stable efficiencies (probably at least 10%) with the highest process yields.

Amorphous silicon is the most well-developed thin film technology to-date and has an interesting avenue of further development through the use of "microcrystalline" silicon which seeks to combine the stable high efficiencies of crystalline Si technology with the simpler and cheaper large area deposition technology of amorphous silicon.

However, conventional c-Si manufacturing technology has continued its steady improvement year by year and its production costs are still falling too.

The emerging thin film technologies are starting to make significant in-roads in to grid connect markets, particularly in Germany, but crystalline technologies still dominate the market. Thin films have long held a niche position in low power (<50W) and consumer electronics applications, and may offer particular design options for building integrated applications.

Opportunity Keeps On Driving To Endeavour Crater


Opportunity continues to make good progress toward Endeavour crater as solar energy levels improve.

On Sol 2281 (June 24, 2010), the rover completed over 70 meters (230 feet), driving east/southeast.

On Sol 2283 (June 26, 2010), the rover headed 57 meters (187 feet) to the northeast to avoid some large ripples.

The rover drove again on Sol 2286 (June 29, 2010), covering over 70 meters (230 feet) to the east.

As of Sol 2286 (June 29, 2010), solar array energy production has improved to 354 watt-hours, atmospheric opacity (Tau) was 0.295 and the solar array dust factor is 0.577.

Total odometry is 21,408.21 meters (21.41 kilometers, or 13.30 miles).

Shrinking the cost for solar power


One of the big problems with solar power has been that it costs more than electricity generated by conventional means. But some experts think that, under certain circumstances, the premium for solar power can be erased, without subsidies or dramatic technical breakthroughs.

A sufficiently large solar thermal power plant (also called concentrated solar power, or CSP) could potentially generate electricity at about the same cost as electricity from a conventional gas-burning power plant, experts say.

It's not easy. The plant would also have to come with a large energy storage system, be built next to others and be located close to users. To date, no one has completed a facility that comports to all of these parameters, said Fred Morse, an energy analyst who has studied the issue.

"Solar thermal is available at much more attractive prices than solar photovoltaic. The land mass isn't huge, but it does take a while to build these," said Stephan Dolezalek, a managing partner and co-head of the clean tech practice at venture firm Vantage Point Venture Partners, an investor in Bright Source Energy, which builds solar thermal plants and components.

Both Dolezalek and Jiang Lin, who heads up the China Energy Group at the Lawrence Berkeley National Laboratory, said that solar thermal is likely the most promising technology in the entire alternative-energy field right now.

When asked when solar thermal can hit parity, Lin responded "now."

Thermal by the numbers
Conventionally generated electricity ranges between 5 and 18 cents per kilowatt hour (the amount of money to get a kilowatt of power for an hour) but in most places it's below 10 cents, according to the Energy Information Agency. Solar thermal costs around 15 to 17 cents a kilowatt hour, according to statistics from Schott, a German company that makes solar thermal equipment.

A solar thermal plant would need a facility to store the heat harvested in the day by its sunlight-concentrating mirrors so that the heat could be used to generate electricity at night. "You need the kind of system that can run in the evening," Morse said. At some sites, such as Nevada Solar One, excess heat is stored in molten salt and released at night to run the turbine.

The plant, ideally, should be capable of generating about 300 megawatts of electricity. Those plants can churn out electricity at about 13 cents a kilowatt.

That's still a relatively high price, so utilities would need to group two, three or more 300-megawatt plants together to share operational resources, Morse said. "They could share control rooms or spare parts," he said. That would knock the price closer to 11 cents a kilowatt hour.

"Under 10 cents is sort of the magic line," he said.

Dolezalek puts it another way: the plants need to be around 500 megawatts in size. Most solar thermal plants right now aren't that big. The 22-year-old thermal plant in California's Mojave Desert is 354 megawatts. Utility company Southern California Edison is erecting a 500-megawatt plant scheduled to open in 2009.

By 2014, solar thermal plants located in the Southwest could crank out nearly 3 gigawatts of power, estimated Travis Bradford of the Prometheus Institute for Sustainable Development, a nonprofit based in Cambridge, Mass. That's enough for about 1 million homes.

Costs can then be reduced further by building the plants close to consumers. It costs about $1.5 million per mile for transmission lines, according to statistics from Acciona Solar Power, which owns solar thermal plants. Solar thermal plants work best in arid deserts that get little rainfall. Since some of the fastest-growing cities in the world are located in sun belts, that's less of a problem than it used to be.

But getting to that point isn't easy. Land-use hearings and permits can drag on for years while construction costs rise. The amount of land required can be an issue too: the 354-megawatt plant in California occupies 1,000 acres. Larger plants would need more land, while smaller plants result in higher costs per kilowatt hour.

Even if all of these factors could be completely optimized, solar thermal power plants would likely not produce electricity at a level that would compete with coal plants. Coal plants, however, will likely be hit with carbon taxes in the near future, which will make solar thermal more competitive. Still, at less than 10 cents a kilowatt, solar thermal would be competitive with electricity from gas-powered plants.

Utilities will also likely work hard to lower the costs of solar thermal in the coming decades, Morse added. Utilities are under mandates to increase their renewable energy sources. Citizen groups often complain about wind turbines and the wind doesn't blow at a constant, predictable rate. Several companies are intent on tapping heat from under the surface of the earth to generate power. Geothermal power, however, works best only in certain locations.

"There is an enough flat, unproductive land in the U.S. to power the U.S.," Morse said. "We just don't have the wires to get there. Eisenhower built the national highway system. Some president will build the national grid."

SOLAR ELECTRICITY EXPLAINED

Solar electricity is created by using Photovoltaic (PV) technologyby converting solar energy into solar electricity from sunlight. Photovoltaic systems use sunlight to power ordinary electrical equipment, for example, household appliances, computers and lighting. The photovoltaic (PV) process converts free solar energy - the most abundant energy source on the planet - directly into solar power. Note that this is not the familiar "passive" or Solar electricity thermal technology used for space heating and hot water production.

A PV cell consists of two or more thin layers of semi-conducting material, most commonly silicon. When the silicon is exposed to light, electrical charges are generated and this can be conducted away by metal contacts as direct current (DC). The electrical output from a single cell is small, so multiple cells are connected together and encapsulated (usually behind glass) to form a module (sometimes referred to as a "panel"). The PV module is the principle building block of a PV system and any number of modules can be connected together to give the desired electrical output.

PV equipment has no moving parts and as a result requires minimal maintenance. It generates solar electricity without producing emissions of greenhouse or any other gases, and its operation is virtually silent.

What is PV power used for?

PV systems supply solar electricity to many applications in the UK, ranging from systems supplying power to city buildings (which are also connected to the normal local solar power network) to systems supplying power to garden lights or to remote telecom relay stations.

The main area of interest in the UK today is grid connect PV systems. These systems are connected to the local solar electricity network. This means that during the day, the solar electricity generated by the PV system can either be used immediately (which is normal for systems installed on offices and other commercial buildings), or can be sold to one of the electricity supply companies (which is more common for domestic systems where the occupier may be out during the day). In the evening, when the electrical system is unable to provide the electricity required, power can be bought back from the network. In effect, the grid is acting as a Solar electricity energy storage system, which means the PV system does not need to include battery storage.

Grid connect PV systems are often integrated into buildings. PV technology is ideally suited to use on buildings, providing pollution and noise-free solar power without using extra space. The use of photovoltaics on buildings has grown substantially in the UK over the last few years, with many impressive examples already in operation.

PV systems can be incorporated into buildings in various ways. Sloping rooftops are an ideal site, where modules can simply be mounted using frames. Photovoltaic systems can also be incorporated into the actual building fabric, for example PV roof tiles are now available which can be fitted as would standard tiles. In addition, PV can also be incorporated as building facades, canopies and sky lights amongst many other applications.

Stand-alone photovoltaic systems have been used for many years in the UK to supply solar electricity to applications where grid solar power supplies are unavailable or difficult to connect to. Examples include monitoring stations, radio repeater stations, telephone kiosks and street lighting. There is also a substantial market for PV technology in the leisure industry, with battery chargers for boats and caravans, as well as for powering garden equipment such as solar electricity fountains. These systems normally use batteries to store the solar power, if larger amounts are required they can be combined with another source of power - a biomass generator, a wind turbine or diesel generator to form a hybrid power supply system.

PV technology is also widely used in the developing world. The technology is particularly suited here, where electricity grids are unreliable or non-existent, with remote locations often making PV power supply the most economic option. In addition, many developing countries have high solar radiation levels year round.

Electricity from: Solar Energy

The ultimate source of much of the world's energy is the sun, which provides the earth with light, heat and radiation. While many technologies derive fuel from one form of solar energy or another, there are also technologies that directly transform the sun's energy into electricity.

The sun bathes the earth in a steady, enormous flow of radiant energy that far exceeds what the world requires for electricity fuel.

Since generating electricity directly from sunlight does not deplete any of the earth's natural resources and supplies the earth with energy continuously, solar energy is a renewable source of electricity generation. Solar energy is our earth's primary source of renewable energy.

There are two different approaches to generate electricity from the sun: photovoltaic (PV) and solar-thermal technologies.

* Initially developed for the space program over 30 years ago, PV, like a fuel cell, relies upon chemical reactions to generate electricity. PV cells are small, square shaped semiconductors manufactured in thin film layers from silicon and other conductive materials. When sunlight strikes the PV cell, chemical reactions release electrons, generating electric current. The small current from individual PV cells, which are installed in modules, can power individual homes and businesses or can be plugged into the bulk electricity grid.

* Solar-thermal technologies are, more or less, a traditional electricity generating technology. They use the sun's heat to create steam to drive an electric generator. Parabolic trough systems, like those operating in southern California, use reflectors to concentrate sunlight to heat oil which in turn creates steam to drive a standard turbine.

Two other solar-thermal technologies are nearing commercial status. Parabolic dish systems concentrate sunlight to heat gaseous hydrogen or helium or liquid sodium to create pressurized gas or steam to drive a turbine to generate electricity. Central receiver systems feature mirrors that reflect sunlight on to a large tower filled with fluid that when heated creates steam to drive a turbine.


What are the environmental impacts?

PV systems operate without producing air, water or solid wastes.

When constructed as grid-connected central station systems, they require significant land, which can impact existing ecosystems. Nevertheless, most PV installations come in the form of distributed systems that use little or no land since the panels are installed on buildings.

Manufacturing PV cells involves the generation of some hazardous materials. Nonetheless, appropriate handling of these small quantities of hazardous material reduces risks of exposure to humans and to the environment.

Like PV, solar-thermal technologies generate zero air emissions, though some emissions are created during the manufacture of both technologies. Water use for solar thermal plants is similar to amounts needed for a comparably sized coal or nuclear plants.

The biggest concern with solar technologies may be land use...

...since five acres of land are often needed for each megawatt of capacity. PV can eliminate the land use impacts by integrating the generators into building construction, eliminating the need for dedicating land use to PV generation.

How Do You Produce Electricity From Solar Energy


he answer to the question of how do you produce electricity from solar energy is fairly easy to understand once you have a slight knowledge of the subject.
Before you are able to produce electricity through solar energy, there needs to be some form of solar cell or panel.
The solar panels are made of a semi-conductive material, the most common material is silicon.
The semi-conductive material contains electrons which are quite happy just sitting there.
When photons (contained within the suns rays) hit the solar cells, the electrons absorb this solar energy, transforming them into conduction electrons.
If the energy of these photons is great enough, then the electrons are able to become free, and carry an electric charge through a circuit to the destination.
Any electrons that do not receive enough energy simply warm up, which heats your cell or panel, resulting in lowering the efficiency of the cell.
The lowering in efficiency is down to two main factors and they are; that the cell is not working to its full potential (e.g. some electrons may be lost), the second factor is when the electrons release heat, the panel also becomes warm, interfering with other aspects of the solar cells.
The more solar cells contained in a solar panel, or solar array, means the more output you will receive.
Quality cells are also a major factor in efficiency. If you purchase more expensive natural energy technologies, you are more likely to have a more efficient cell.
Another factor which affects solar panel efficiency is location. Obviously nearer the equator, you will receive a slightly better output with a given cell, but solar cells should always be facing the direction of the sun, and have no objects blocking the suns rays.
So there we have a basic understand of how you produce solar electricity from using energy within the suns rays.