Solar Power Systems

2:04 AM Solar Power Systems 1 Comment

Solar power systems have experienced a surge in popularity because of the rising cost of conventional energy sources. By, adding a solar energy system to your home, you can recoup your investment over a few years and continue to save money on utility bills for the life of your system.

The lion's share of the electric utility expense is used in heating the house in the winter and cooling the house during summer months. If you live in the northern climates with intensely cold winters, heating bills during the winter can be astronomical for a home that is only mid-sized. In the Deep South, the greatest expense is often from cooling the house during the hot, humid spring, summer and fall months. Solar power systems, lower these expenses and even help in the cost of hot water generation and cooking.

Perhaps the simplest solar power system to install is a solar hot water heater that can produce some or all of the household needs. In most households, however, this is a small share of the utility expense compared to heating and cooling. Simply, solar hot water heating systems can be built in a weekend and installed by a good handy person with tools that are probably already around the house.

To turn the focus on to production of solar electricity, however, is a bit more complex. Solar power systems that collect the sun's solar rays require a roof-top solar collector panel or panels. In most cases where a good share of the home's electric power is to be generated by the sun, several collectors are often required. These can be purchased or home-built using designs purchased from online sources or found in the local library. The engineering is reasonably simple and construction is not that difficult.

Read More

How does Solar power Works Without the Sun?

1:01 AM How does Solar power Works Without the Sun? 1 Comment

1. • Alternative power sources such as solar and wind are being developed because they reduce pollution and green-house gas emissions while increasing the United State's energy independence. A major problem with solar energy is that it is only available when the sun is shining. Therefore, methods to transform and either store the energy until needed or combine it with energy from other sources have been developed.

   Thermal Energy:

   • One of the easiest ways to store solar energy is as heat. Buildings using passive solar heating are designed with large, south-facing windows and ceramic tile floors. During the day, the tiles absorb heat which is radiated during the night. Swimming pools are heated by pumping pool water through an array of solar collectors before being returned to the pool. During cloudy periods and night time, the water gradually cools. Using a cover when the pool is not in use greatly increases the retention of heat.

   Battery:

   • Solar energy can be converted by photovoltaic cells into direct current (dc) energy and stored in rechargeable batteries. When the sun is not available, the batteries provide electricity to devices such as lights, refrigerators, computers and televisions. If alternating current (ac) is needed, an inverter is added to the system. A solar power system with batteries is frequently used in remote areas where connecting to the electric power grid is not possible or cost prohibitive.

   Utility Grid:

   • Many owners of photovoltaic (PV) solar power systems are also connected to the utility grid. When the sun shines and their system is generating electricity, the solar generated electricity powers their household and any excess energy is sold back to the utility company. When the solar system is not generating electricity, the household buys electricity from the utility. At the end of the billing period, the credit for electricity sold is deducted from the cost of electricity bought. The federal government requires utilities to purchase excess electricity from homes and businesses using alternative energy generation. Some utility companies use large solar concentrator systems or photovoltaic power plants to generate power. Because the utility also has other sources of power, such as coal or hydro, the utility is able to balance the solar electricity generation with other sources to ensure a constant power supply.

   Future:

   • The U.S. Department of Energy (DOE) recognizes that increasing the use of solar energy requires new and better ways of storing the energy until it is needed. In 2008, DOE funded 15 new projects at a cost of $67.6 million to develop heat transfer and solar power storage.
     Several of these projects are researching ways to use latent heat transfer to store energy. When material is heated or cooled, it can change state. For example, water changes from a solid (ice) to a liquid (water) and then to a vapor (steam). In order to change state, heat is either absorbed or given off. This process of giving off or absorbing heat without changing temperature is known as latent heat transfer. When a solid becomes liquid, latent heat is absorbed. When the liquid becomes solid, the latent heat is released. Molten salt and other materials are being explored to find ones whose phase change can effectively store solar energy and release it when needed.

Read More

How Does Solar Energy Transform Into Electricity?

12:57 AM How Does Solar Energy Transform Into Electricity? 1 Comment

Technology is available to take solar energy and convert it into electricity in order to power space ships and satellites and hand-held devices and provide electrical energy to homes. There are two primary methods for creating electricity from solar power. Photovoltaic technology coverts solar energy into electricity, and solar thermal energy generates electricity through a heating process.

1. Photovoltaic:

   • Photovoltaic cells are made from a material such as silicon that coverts the sun's light into energy when it is absorbed into the substance. Each cell is designed to produce one or two watts of electricity, and when the cells are combined in panels or arrays, they can generate more power. Electricity that is generated through solar panels has to be converted into AC power by conversion equipment in order to be used within a home or business.

   Solar Thermal Power:

   • Solar thermal power involves using huge solar-energy collecting tubes or pipes that have a fluid contained inside of them. Once the tubes or pipes are heated up, the fluid is then cycled through a solar power plant that contains a large body of water. Once this water is heated up by the tubes or pipes it produces steam. When the steam is hot enough, it produces mechanical energy that turns a turbine and electricity is created when this turbine powers a generator.

   Solar Dishes:

   • Solar dishes collect solar energy by concentrating solar collectors at the dish, and this causes the dish to heat up to nearly 1,200 degrees. Electrical power in solar dishes is produced by compressing a cold fluid through the use of a engine. Once this fluid is compressed it is then heated up by the solar dish and this causes it to expand through a turbine and a piston in order to create mechanical energy. This mechanical energy is used to power a generator that produces electricity.

Read More

Process of Solar Energy

12:50 AM Process of Solar Energy 1 Comment

 

1. What is Solar Energy?

   • With current energy prices rising every year and stores of natural energy quickly depleting, alternative sources of power are beginning to take center stage. Solar energy is one of the most abundant sources of heat and electricity on the planet and scientists are beginning to develop methods for harnessing it to power our homes and workplaces.
     There are two classifications for solar power that denote exactly how the solar energy is used: direct and indirect. Photovoltaic cells are a direct form of energy, since the solar energy is directly converted into energy; a black bottomed pool that collects solar energy to heat it would also be considered direct. An indirect method require one or more intermediary steps in order to convert sunlight into power. Plant photosynthesis is indirect because it creates possible fuel sources (carbon, biofuel, etc.) instead of energy itself.
     There are two main ways of tapping the sun for energy, solar thermal power and photovoltaic electricity. Solar thermal energy gathers heat energy from the sun to operate turbines that generate electricity. Photovoltaic electricity is generated using specialized silicon cells that interact with sunlight to create an electric current.

   Solar Thermal Power:

   • Solar thermal power is the process through which the sun's heat energy is collected and used to create electrical current. Solar thermal energy collectors resemble satellite arrays, with a dish covered that concentrates the sun's heat on a small point. Once collected, this thermal energy boils water, and in turn, that steam is used to to turn turbines that create the electricity. This process is an indirect method of creating solar energy and, unfortunately, can only be used when the sun is shining.

   Photovoltaic Electricity:

   • Photovoltaic energy is a direct form of solar energy that converts the sun's rays directly into electricity. Photovoltaic cells, little chips made of silicon that absorb the sun's energy, are made of two layers of specially treated silicon. When light hits the bottom layer, photons knock electrons loose creating an imbalance in charges between the top and bottom. Electrons flow freely through the connector when the two layers are connected, creating an electric current. Small photovoltaic cells are inexpensive to build and maintain, and you can see them at work on any old, sunlight-powered calculator.

Read More

Mecasolar trackers adapted for use at 600 kW CPV plant in Italy

12:41 AM Mecasolar trackers adapted for use at 600 kW CPV plant in Italy 1 Comment

On January 11th, 2012 Mecasolar (Fustiñana, Spain) reported that it has delivered 55 tracking systems to a 600 kW concentrating solar photovoltaic (CPV) plant in Italy. These trackers will be retrofitted to the plant, which is currently operating.

Each tracker will support 48 230 watt CPV modules, for a total of 11 kW per tracker. The CPV modules use a 5x concentration design, and Mecasolar states that this project shows that its trackers can be easily adapted to other types of low-concentration CPV modules available on the market.

Precision of 0.5 degrees anticipated

This is the first time that Mecasolar trackers have been adapted to low-concentration CPV modules, and the company expects its trackers to achieve a precision of 0.5 degrees. Mecasolar trackers used with crystalline silicon PV modules have an accuracy between 2.88 degrees and 1.44 degrees.

The CPV plant also features Tripower 10000 inverters from SMA Solar Technology AG (Niestetal, Germany).

The company states that it will launch a concentration tracker in 2012, and in December 2011 launched a 114 kW polar-aligned tracker.

Read More

New Plastic Solar Design Promises Efficient Power

11:00 PM New Plastic Solar Design Promises Efficient Power 1 Comment

In a quiet research laboratory here, an Inventor is developing solar power devices designed to operate four or five times more efficiently than the beat photovoltaic cells now in use, and at a small fraction of the cost.
Alvin M. Marks, an inventor who, holds patents for a 3-D movie process and polarized film for sunglasses, is working with the Westinghouse Electric Corporation to build prototypes of the solar power devices. He received one patent for the devices earlier this year and another in 1984.
The Exxon Corporation recently offered $9 million for Mr. Marks's patents, and for Phototherm, the small company that controls them. according to Gerard J. Aitken 3rd, chairman of Phototherm's board. But company officials chose not to sell; instead they signed the development contract with Westinghouse, which says it is particularly interested in the technology's applications for Strategic Defense Initiative, or Star Wars.
Mr. Marks says solar panels made with Lepcon or Lumeloid, the materials he patented, could turn 70 to 80 percent of the energy from sunlight they receive into electricity. Most photovoltaic cells are only about 15 percent efficient. The electricity would cost three or four cents per kilowatt hour, as against about 10 cents a kilowatt hour for commercially generated electric power. Most photovoltaic cells produce energy for around $1 per kilowatt hour.
Typical photovoltaic cells use layers of chemically treated metals that produce electric current when struck by sunlight. The basic problem has always been the quantity of current produced per unit cost of the materials used to produce it.
Lepcon, which was a preliminary design, consists of glass panels covered with a vast array of millions of aluminum or copper strips, each less than a micron or thousandth of a millimeter wide. As sunlight hits the metal strips, the energy in the light is transferred to electrons in the metal. which escape at one end in the form of electricity.
Lumeloid uses a similar approach. but substitutes cheaper, filmlike sheets of plastic for the glass panels and covers the plastic with conductive polymers, long chains of molecular plastic units. Lumeloid is easier to manufacture and handle than Lepcon. The company declines, for competitive reasons, to identify the chemicals it uses to produce Lumeloid polymers.
There are as yet no large-scale working prototypes of Mr. Mark's invention, and some scientists have expressed caution in assessing it. "It is beyond our technological fabrication capability at present," said Dr. Edward D. Wolf, the director of the national research facility for submicron structures at Cornell University, who has studied Mr Marks's work."But it's an interesting concept."
Professor Stuart A Rice, dean of the division of physical sciences at the University of Chicago, has also reviewed the patents.
"It is an intellectually challenging idea," he said, "I do not know whether it can be brought into practice, so I don't know whether to be optimistic or pessimistic. If it turned out to work, and was very efficient, it would he very significant."
Mr Marks said he believed Lumeloid would be available for commercial use within two or three years. He added that Lepcon and Lumeloid could be used to create lasers, an application he said he had discussed with the Pentagon in conjunction with Westinghouse.
Mr Marks conceded that getting his ideas to the major prototype stage would cost around $5 million. Commercial production of solar panels would cost between $30 million to $5O million, he estimated, and the preliminary work, supported by Westinghouse, is now underway, he said.
Phototherm plans a $15 million initial public stock offering soon to help subsidize development of the solar patents.
Mr Marks has more than 100 other patents, Including the film used on polarized sunglasses, and the process to make 3D movies, and he was also an energy adviser to president John F. Kennedy.

Read More

Nanosolar and EDF Energies Nouvelles Commission Projects Totaling Six Megawatts

10:56 PM Nanosolar and EDF Energies Nouvelles Commission Projects Totaling Six Megawatts No Comments

Bordeaux and Oregon projects develop field performance track record from leader in thin film solar printing  
SAN JOSE, Calif. – Nov. 15, 2011 – Thin film solar printing leader Nanosolar, Inc. today announced its supply of Nanosolar Utility Panels to two separate installations totaling close to six megawatts (MWp) in partnership with EDF Energies Nouvelles (EDF EN) and its US subsidiary enXco. These projects are the latest result of a long-standing collaboration between Nanosolar and EDF EN.  
“These latest projects to be commissioned with Nanosolar panels are a significant validation of both our close relationship with EDF EN and the low-cost potential of our thin film printing technology, which we believe can fundamentally change the solar and energy industries,” said Geoff Tate, CEO of Nanosolar, Inc. “EDF Energies Nouvelles continues to be a strategic, collaborative partner to Nanosolar in the development, testing, and installation of our printing technology.”    
Gabardan, France  
Three MWp of Nanosolar Utility Panels were installed this past summer and commissioned in September as part of a larger EDF EN solar farm in Gabardan, France. ColSun, a joint venture of EDF Energies Nouvelles and Belectric, installed the project using SMA central inverters. This is the first utility-scale installation of Nanosolar Utility Panels by EDF EN.  
Amity, Oregon  
A second approximately three MWp Nanosolar Utility Panel installation was constructed this summer and was commissioned in November 2011 near Amity, Oregon. Developed, designed and installed by enXco, the US subsidiary of EDF EN, at two separate sites using Advanced Energy inverters, the projects connect to the Portland General Electric distribution system.  
“Nanosolar’s thin film printing process and the Nanosolar Utility Panel continue to show great promise for low-cost solar installations,” said Pierre-Guy Therond, Head of New Technologies at EDF EN. “We continue to support the development and progress of this disruptive technology from the lab through to delivery in the field.  
Nanosolar Utility Panel  
Nanosolar’s innovative, roll-to-roll printing process and utility-scale panel design enables the Nanosolar Utility Panel to significantly reduce both manufacturing costs and balance of systems costs in multi-megawatt installations. In addition, it is the first solar panel to be certified to operate at up to 1500 system volts. These system design features allow for balance of systems cost savings of up to 30 percent over competing thin film solar panels in utility-scale power plants.  
Nanosolar thin film solar cells are printed at the company’s headquarters and manufacturing facility in San Jose, California. The Nanosolar Utility Panel can be assembled close to market demand in order to leverage local resources and minimize logistics costs.  
For more information about Nanosolar and its innovative solar printing technology, please visit http://www.nanosolar.com.  
About Nanosolar, Inc.
Nanosolar designs, engineers, and manufactures innovative thin film solar cells and panels based on printing CIGS (Copper, Indium, Gallium, Selenium) and nanoparticle inks. The company’s first product, the Nanosolar Utility Panel, enables competitively priced peak power and installed system economics at utility-scale. With headquarters in San Jose, CA, Nanosolar operates the industry’s first roll-to-roll solar cell printing factory in San Jose, California and a panel-assembly factory in Luckenwalde, Germany

Read More

Greenhouses and Solar Power: Crop Testing With a Special Photovoltaic Panel for Greenhouses

3:11 AM Greenhouses and Solar Power: Crop Testing With a Special Photovoltaic Panel for Greenhouses 1 Comment

                                                              Greenhouse panels

With the support of the ULMA Group's innovation area, ULMA Agrícola, following the agreement signed with Tecnalia through its Energy Unit, has installed photovoltaic modules on one of its two glass greenhouse units measuring approximately 400 m².

The new photovoltaic module developed by the ULMA Agrícola consortium, the innovation area of the ULMA Group, and Tecnalia allows electricity to be generated without the crops being affected by over-shading. Depending on the season of the year, solar radiation can be diverted by taking advantage of the annual oscillation in the height of the sun's trajectory; this is achieved through a lens-based optical system. Without the need for any solar mechanical monitoring, the technology allows the needs imposed by any crop to be met. So during the winter (October-February), the light inside the greenhouse, a key parameter for correct plant development, barely falls. But in summer the optical system diverts solar radiation towards the photovoltaic cells that make up the module, thus achieving a dual aim: to provide the greenhouse with cooling during the critical period of high temperatures and to increase electricity production through the photovoltaic system.

Right now, tests are being carried out in an ULMA Agrícola greenhouse belonging to the Neiker-Tecnalia R+D centre and located in Derio (Bizkaia, Basque Country). The crops selected for the initial tests are tomato and pepper. These two crops have been selected for the following reasons: they are two of the most common worldwide, they require a very large amount of light, and they are high added-value products within greenhouse agriculture.

In the tests conducted throughout the summer, the most critical parameters of the crop were measured, like total and PAR radiation, humidity and temperature. In addition, crop quality and production in the photovoltaic module were monitored by comparing them with data obtained under a normal glass roof. Positive results were obtained, and between mid-November and the end of March 2012 a winter test is due to be carried out in which the same values will be monitored and from which similar results are expected to emerge. As regards electricity production, the first measures point to a 15% annual improvement over a standard photovoltaic system.

So the new module allows photovoltaic equipment to coexist with crops. What is more, it acts as an element for the seasonal control of the radiation and interior temperature of the greenhouse, apart from constituting additional support for the farmer's economic activity through the sale and/or private use of the energy obtained.

The technology developed enables the problems associated with winter over-shading and summer radiation to be avoided in a simple, robust and effective way. Having validated this in the field using ULMA Agrícola greenhouses, the consortium is aiming to have a product ready to be marketed by the second half of 2012.

Read More

Paint-On Solar Cells Developed

12:26 PM No Comments

Imagine if the next coat of paint you put on the outside of your home generates electricity from light electricity that can be used to power the appliances and equipment on the inside.

                                This paste of cadmium sulfide-coated titanium dioxide 
                                nanoparticles could turn large surfaces into solar cells. 
                                                        (Credit: : ACS Nano)

A team of researchers at the University of Notre Dame has made a major advance toward this vision by creating an inexpensive "solar paint" that uses semiconducting nanoparticles to produce energy.
"We want to do something transformative, to move beyond current silicon-based solar technology," says Prashant Kamat, John A. Zahm Professor of Science in Chemistry and Biochemistry and an investigator in Notre Dame's Center for Nano Science and Technology (NDnano), who leads the research.
"By incorporating power-producing nanoparticles, called quantum dots, into a spreadable compound, we've made a one-coat solar paint that can be applied to any conductive surface without special equipment."
The team's search for the new material, described in the journal ACS Nano, centered on nano-sized particles of titanium dioxide, which were coated with either cadmium sulfide or cadmium selenide. The particles were then suspended in a water-alcohol mixture to create a paste.
When the paste was brushed onto a transparent conducting material and exposed to light, it created electricity.
"The best light-to-energy conversion efficiency we've reached so far is 1 percent, which is well behind the usual 10 to 15 percent efficiency of commercial silicon solar cells," explains Kamat.
"But this paint can be made cheaply and in large quantities. If we can improve the efficiency somewhat, we may be able to make a real difference in meeting energy needs in the future."
"That's why we've christened the new paint, Sun-Believable," he adds.
Kamat and his team also plan to study ways to improve the stability of the new material.
NDnano is one of the leading nanotechnology centers in the world. Its mission is to study and manipulate the properties of materials and devices, as well as their interfaces with living systems, at the nano-scale.
This research was funded by the Department of Energy's Office of Basic Energy Sciences.

Read More

Solar Panel Saves Electricity

12:10 PM Solar Panel Saves Electricity 1 Comment

Saving electricity usage in your home is really the first big step in the process of going solar. In most cases an average solar power system will not supply you with 100% of your energy needs, so to make the whole thing more cost effective it is vitally important to find as many ways as you can to make your home as energy efficient as possible. Whether you are looking for ways to make sure that your household is living in a more Eco-friendly manner or you are just searching for ways to reduce your electricity bill, you'll find that employing the following measures will help enormously.

Saving Electricity: Perform an energy audit

An energy audit is a complete and thorough analysis of your home and its energy usage. You can do this type of audit yourself but it is pretty time consuming. There are professionals that you can pay to perform an audit but most  energy companies will do this for you either at a low cost or for free. I suggest contacting your energy provider to see if they offer this service, and if they do, have the audit performed. It will give you a very clear picture of where you are at and exactly what you need to do to fix any problems and improve your energy efficiency. If you would like help with doing an energy audit there is a great product called the 'Kill A Watt' . It is a very simple and useful device that lets you assess how efficient your appliances really are.

Saving Electricity: Reduce the use of air conditioners

Your air conditioner is one of the of the biggest electricity hogs in your household. When you want to keep your home cool, why not turn on a ceiling fan instead? Another great way to make sure that you keep your electricity bill down and your home cool is to encourage a cross breeze through your living area by open two windows that happen to face each other. You can also install a solar roof vent and solar attic fan to get rid of unwanted heat from your attic.

Saving Electricity: Keep warm with space heaters

Conversely, when you are looking at making sure that you can conserve electricity, turn down the central air in your home and consider getting space heaters for individual rooms. This can help you make sure that you are going to be able to stay warm while keeping the heating-related electrical costs low. You may also want to turn the heater down when no one is going to be in the house as well.

Saving electricity: Put your computer to sleep

Especially if you have a desktop, you will find that putting your computer to sleep, or even turning it off when you are not using it can improve your electricity costs. Turning it off overnight, when you are not going to be using it, or while you are work can help you save some cash on the electricity usage in your home. If you own a laptop computer you may want to consider a solar charger as opposed to a charger that draws power off your electrical system.

Saving Electricity: When not in use, turn off the lights

This is certainly a basic trick, but the truth of the matter is that it is one that people forget about far too often. Consider all the rooms in your home and how often the light really needs to be on. Take some time to walk around your home and shut off the lights that are not being used. Some people put up little notes or reminders above the switches to help them to remember to turn them off.

Saving Electricity: Use energy efficient light bulbs

As your standard light bulbs burn out you should replace them with energy efficient fluorescent bulbs. They will last way longer and do not use up power like the standard bulbs do.
There is a brand of high tech bulbs called Earth LED that we use that, while pricey, can give you up to 50,000 hours of use. That's 11 years! Here is a couple examples, highly recommended:

Read More

Solar Homes

12:01 PM No Comments

Solar power roof vents will allow you to save money on your energy bills and provide a safe and environmentally friendly solution for your needs. The unit can generally be placed wherever you need more circulation in the air whether it is your attic, workroom or garage. It is possible to save up to thirty percent on your electric bill.
In some situations, it is important to have fresh air circulating at all times. When you are working in your workroom with chemicals you must have a way to keep fresh air in the room to avoid problems with your health. A vent can also prevent mold from accumulating which can also present a serious health threat. When you use an electric vent for these particular areas of your home, you can be sure that your electric bill will go up significantly.
One of the problems that some people have used to argue against using solar powered roof vents is their inability to work well when the sun is not shining. However, it should be noted that the use of solar power is constantly evolving and you can expect that the vents of today are significantly improved over the ones of the past.
The first thing that you will have to consider when you are shopping for a solar powered roof vent is the size of the vent that you will need. While you will be able to shop for your vents online, you should only do this if you are sure of the size that you will need. The best source for advice and the right size vent for your home is in a solar store. There you will be able to find out the correct size for your home so that you can be sure you are getting exactly what you need.
Typically the solar panel that is used for your roof vent will mount in a different location than the vent itself. If you are planning to install the unit on your own, you will not have to deal with any electrical work for the installation of this unit. They operate completely separate from electricity.
We all know the importance of finding alternative energy sources in our lives. The more things you can control in your home through solar, wind and alternative energies, the better you will be serving the environment and your own pocketbook. It is possible to completely get off electricity if you put a great deal of work into finding alternative means of providing energy to your home. Solar power roof vents come as kits available online.

Imagine the amount of money that you could save in a year if you find alternative means of energy for your home. Aside from alternative means of energy, conservation is a good way to save money as well. When you combine both of these methods in your home, you will significantly reduce the amount of money that you are paying out each month in energy bills.
Solar power roof vents are just the start of the process. Once you find out how easy it is to reduce the amount of energy you are using for just one process in your home, you will be eager to use it for other appliances as well. Why not look into solar pool heating, solar lights or solar heating for your home as your next home improvement project. The more we can all do to reduce the amount of energy we are using in our homes the better it will be for the environment and our own wallets.

Read More

Solar Planes

11:51 AM No Comments

A solar plane's flight starts with checks. Check the battery -- it should be charged. Check the ground winds. They shouldn't exceed about 10 miles per hour (16 kilometers per hour), or else the plane could crash on the runway. Check for turbulence in the air because the plane will have to ascend through the turbulent layers. Billows in the clouds are a bad sign. "Wind is your enemy," says Del Frate.

Morning is best for takeoff, when the sun is overhead and there are ample hours of sunlight left in the day. As a runway, you'll need a circle a little more than three football fields across, which is 10 times shorter than an average airport runway. Next, you angle the plane for takeoff, using that circle. You point the plane so the wind blows head-on, but never across it. Crosswinds spell destruction for most solar planes because they can throw the plane in unwanted directions.

When the propellers are online, a combination of battery power and solar energy can start them spinning, and the plane is ready to roll (or be hand-tossed into the air). "The plane takes off at bicycle speeds," says Del Frate, because takeoff is typically done on solar power. As a pilot, usually on the ground, you avoid shadows and steer for maximum sun to preserve power in the battery.

The plane ascends slowly. You make it ascend by speeding its central propellers, tilting it up. By 35,000 feet (10.6 kilometers) or so, you've hit the jet stream. Hold on. In this turbulent layer of the sky, planes like NASA's Helios can bend, from flat to a dramatic "U," with the wind. If the plane didn't bend, the wind could rip it apart. The plane can't stay here, where 747s cruise, because if turbulent wind doesn't kill it, the jet stream will carry it away. 

Above the jet stream, dodge the puffy clouds; they block the sun. Turning is as easy as speeding the propellers on one side of the airplane. By 40,000 feet (12 kilometers), you've entered the stratosphere, a still layer with icy cirrus clouds that don't block your sun. Finally, by 65,000 feet (20 kilometers), you can relax in stillness and practically glide. If you plan to stay up overnight, make sure your battery is charged to run the propellers. Otherwise, you'll start losing altitude.

During flight, a solar plane switches automatically between battery and solar power. When there's sun, it runs the propellers and charges the batteries or fuel cells. To charge the battery faster, the pilot can fly slower. At night or in clouds, the propellers run on the battery or fuel cells alone.

When it's time to land, cut the power to stop the propellers. Solar planes glide down -- engineers would rather make them efficient fliers than fast at landing. "They descend extremely slowly," says Del Frate. "When you're trying to bring one in for a landing, you'd like to grab it and pull it down."

Read More

Solar Cars

11:31 AM No Comments

Remember the race I was talking about last few weeks about solar cars?Well it has come to the finish line and it is in Garden City, Kansas. Imagine going around in a never ending race without going for a gasoline station to feed your mobile up. That is precisely the point they are teaching all of us here that cars can be charged by the use of solar energy. Some critics said that these cars will not reach the pit stop and that the cars will just die because it just depends on the rays of the sun, well by golly, they succeeded and they were at the Community College in Garden City yesterday.
“The cars are going from Fort Worth, Texas, to Boulder, Colo., for the 2010 Hunt-Winston School Solar Car Challenge. Fourteen cars built by high school students stopped Friday at the Garden City Community College campus.”

Read More

NASA Solves Solar Energy's Dust Problem

1:53 AM 1 Comment

Here's a problem for solar energy you may not have thought about: dust. With many of the best sites for solar panels in deserts, the accumulation of dust on top of photovoltaic surfaces can block sunlight and reduce their efficiency by up to 80 percent. And cleaning a huge field of solar panels by hand is a big task. Interestingly, NASA faced a similar problem with the Mars rovers, which had to be able to clean their own panels with no direct human help in a dusty environment.
And the NASA scientists solved it. The self-cleaning technology they came up with uses "a layer of an electrically sensitive material to coat each [solar] panel. Sensors detect when dust concentrations reach a critical level and then an electric charge energies es the material sending a dust-repelling wave across its surface."
The same technology is expected to be commercially available within the year. Unexpected breakthroughs like this are one of the best reasons to keep a robust space program going.

Read More

Introduction

1:46 AM No Comments

Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar energy technologies include solar heating, solar photovoltaics, solar thermal electricity and solar architecture, which can make considerable contributions to solving some of the most urgent problems the world now faces.
Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.
In 2011, the International Energy Agency said that "the development of affordable, inexhaustible and clean solar energy technologies will have huge longer-term benefits. It will increase countries’ energy security through reliance on an indigenous, inexhaustible and mostly import-independent resource, enhance sustainability, reduce pollution, lower the costs of mitigating climate change, and keep fossil fuel prices lower than otherwise. These advantages are global. Hence the additional costs of the incentives for early deployment should be considered learning investments; they must be wisely spent and need to be widely shared"

Read More