Cheap Solar Panels | U.S. solar panel reviews. The best low-cost and DIY domestic solar panel guides and kits reviewed. Easily build and install your own solar panels at home. http://www.cheap-solar-panels.net/index.html en-us energy,environment,efficiency,home,diy neville@nevillepettersson.com 2011 Cheap Solar Panels Cheap Solar Panels For Your Home Congratulations on finding this site! With the glut of high end solar franchises still peddling their wares and dominating the search engines it's hard to get the message out that expensive solar is DEAD. That's right, you no longer need to pay the ridiculous costs, sometimes going into the tens of thousands of dollars, to get solar roof panels on your home. Cheap solar panels are now extremely easy to buy and put together yourself. All you need to know is where to get them and how to do it. Cheap Solar Panels Do It Yourself The best way to get cheap solar panels on your roof is to source the panels and other parts yourself. We'd highly recommend you get a professional guide at this stage which contains a directory of places to go to get all of these parts cheaply. It's also good to have a guide because it will tell you exactly how to put all the parts together, what each part does and also give you advice on outsourcing the project to a local electrician or contractor if you're not that technically minded. Our home page has links to the best DIY solar guides as well as solar panel reviews to help you start out on the right foot. Cheap Solar Panels From China The new era of low-cost domestic solar panels has a lot do with the cheap solar panels from China. Most people don't realize this, but China is the World's largest producer of solar panels. It's no secret that China has many advantages for manufacturing which has practically forced the big solar companies to open production there. Suntech is the biggest solar panel manufacturer in the World, mainly as a result of being the first major player to move it's base of operations onto the mainland. The second and third largest solar manufacturers, Yingli and Trina Solar respectively, have also based their main production plants in China. The Chinese government has been quick to capitalize on big business investment by providing making the process of setting up production as easy as possible and being flexible around new investors. Cheap Solar Panels For Homes In the long term everyone benefits because of higher competition and lower production costs the solar panels are becoming cheaper by the day. A few things to bear in mind when shopping for cheap solar panels is not to think that just because the units are made in China that they're not the best solar panels. As mentioned earlier, all of the big solar producers are now based in China so the panels you'll get are exactly the same quality as anywhere in the U.S. or Europe. However, instead of paying prices of $2.50 - $3.00 per watt you'll only pay around $1.00 - $1.50 per watt for the same panels from China. Where To Get Cheap Solar Panels Firstly, whatever you do don't use search engines like Google to try and find places to buy solar panels in China, you'll get either spammed or ripped off. Either go to the manufacturer directly, Suntech, Yingli or Trina Solar, or what is most recommended is that you use the preferred dealers listed in our one of the Top 10 home energy guides. Doing it this way ensures your solar panels will be the real deal. Also, some of the listed sites have awesome specials and discounts not available from the manufacturers sites. http://www.cheap-solar-panels.net/index.html 17 Aug 2011 15:05:02 GMT energy,environment,efficiency,home,diy neville@nevillepettersson.com Monocrystalline Solar Panels Monocrystalline solar panels are the most efficient solar panels you can buy. As the name suggests, monocrystalline panels are made out of single pure pieces of silicon. They are made from quartz crystals which are melted down under extreme temperatures. The molten silicon is then purified and set into cylindrical ingots of very pure silicon. These are then sliced into flat pieces, phosphorus is added and then they're ready to go. Monocrystalline solar panels are currently the best solar panels you can get, but whatever you do, be sure to educate yourself first about solar technology before you go spending any money. Monocrystalline Solar Panels Efficiency Monocrystalline solar panels are the most efficient solar panels. By definition this means that they convert the highest amount of solar energy into electricity of any panel, both commercial and domestic solar panels. It is strongly believed that the gross efficiency of any photovoltaic solar panel, be it monocrystalline, polycrystalline or thin film, will never exceed 29%. In fact, the maximum predicted efficiency is actually believed to be around 25% due to factors like conductivity and heat. The two most efficient solar panels available for sale are from Sanyo and SunPower. The Sanyo HIT Series range, which receive excellent solar panel reviews, offer efficiencies of up to 21.6%. SunPower solar panels offer the highest efficiency rates of up to 22.5% for most of their top of the range solar roof panels. In June 2010 SunPower broke the world record for commercially produced solar cells at 24.2%. However, these cells are currently not available for domestic use. Mono panel cell efficiency is expected to drop by an average of 0.5% every year. Monocrystalline Solar Panels vs. Thin Film Solar Monocrystalline are the best solar panels in situations where space is limited such as inner city apartments or bespoke design homes. Thin film are the cheapest solar panels initially, however it's important to take into account the lifetime value of the system. It is also widely known that thin film systems are more costly to install as they require more work and materials. This is an important consideration in terms of your overall solar panel cost because even though your cost per watt may be cheaper, you'll need more thin film panels overall, compared to mono panels, which will increase slightly your installation and mounting costs. In terms of environmental footprint thin film solar cells require less energy to produce than comparable monocrystalline solar panels which makes them more efficient in terms of production. However, some thin film solar cells contain Cadmium which is a heavy metal that is a toxic carcinogen to humans and animals. If not disposed of correctly, these thin film cells could contribute to toxic waste. Mono panels contain no such substances and are not hazardous to the environment in any way. Monocrystalline Solar Panels vs. Polycrystalline Solar Panels As with thin film cells, polycrystalline are a hybrid form of cheap solar panels destined to flood the domestic solar power market. Poly panels are also cheaper to produce and require lower energy input than comparable mono panels. However, they also offer lower efficiencies a shorter life-span than the slightly more expensive mono panels. Here are some points to consider when thinking about which type of solar panels for your home to invest in: Firstly, if you live in tornado or hurricane prone areas or anywhere else where you're in danger of damaging your panels (falling branches or severe hail stones), be sure to check that your panels will come under your home insurance. Monocrystalline panels are more fragile, so will probably not be the most practical option if you fit into this category. Secondly, be aware that in extreme temperatures (greater than 115 degrees), you will experience a drop in efficiency between 12-15% from monocrystalline solar panels. In polycrystalline panels this drop will be higher, therefore making mono panels the better option for hotter climates. Finally, you need to figure out if the cheap PV solar panels are worth it overall taking into account your energy needs and long term plans. There have been cases of home owners ripping out their original thin film and polycrystalline systems and replacing them with the more efficient monocrystalline panels to boost the size and output of their system. http://www.cheap-solar-panels.net/monocrystalline-solar-panels.html 23 Aug 2011 04:20:53 GMT energy,environment,efficiency,home,diy neville@nevillepettersson.com Rooftop Solar Power Rooftop solar power in the U.S. is one of the most fastest growing markets in the country. Fuelled by high electricity prices and a new environmental consciousness, more and more consumers are taking up the challenge to install their own domestic solar panels. It's no longer a secret anymore, cheap solar panels are now available for the regular consumer and are now easier than ever to mount yourself. Even the White House has got solar panels now! However, I'm pretty sure the president wasn't up there with his screwdriver. Rooftop Solar Stats The U.S. currently has about 600 megawatts of rooftop solar photovoltaic panel installations. The majority of our solar energy production is still coming from thermal solar, but this trend is slowly starting to move towards photovoltaics. China, who are currently the World's largest solar panel producer, are currently running at around 300 megawatts capacity for solar roof panels. This is only half of what the U.S. is currently doing but China has plans to increase this capacity to 3 gigawatts (GW) of rooftop solar by 2015 and 25 GW by 2020. With access to cheap solar panels right on their doorstep China is tipped to soon become the World leader in domestic solar power production and output. Rooftop Solar Costs The good news is that rooftop solar panel prices are tumbling. This is mainly due to the increased supply coming offshore (mainly China), and also a decrease in demand from countries within the European Union. Since 2009 the solar panel cost for a basic home system has fallen by around 25%. If you add in the Federal and State tax breaks and subsidies you're looking at savings of up to 75%. Rooftop Solar System The best rooftop solar panels to get are the ones you can install yourself. It's now a fact that cheap DIY solar is the definitely the only way to go. Expensive solar systems are a thing of the past. It's no longer a case of are solar panels worth it? The answer is always going to be YES! The most efficient solar panels are still the monocrystalline solar panels as they have a higher output and also will last longer than polycrystalline panels or solar panel shingles. If you're seriously looking at a rooftop solar system be sure to get one of Top 10 home renewable energy guides. These guides have the best information on how to find, assemble and install solar panels on your home. Rooftop Solar Challenge The U.S. Department of Energy is currently running a competition called the Rooftop Solar Challenge, which aims to help reduce the red tape and paper work currently preventing many people from accessing the tax breaks and subsidies offered by the Federal and State authorities. This is an open competition and the winning team will receive funds to actually implement their plan. The whole point of this exercise is to hopefully make getting solar panels for your home easier, faster and cheaper than the current system which can be quite convoluted. http://www.cheap-solar-panels.net/rooftop-solar.html 06 Sep 2011 03:30:44 GMT energy,environment,efficiency,home,diy neville@nevillepettersson.com Solar Energy Pros and Cons If you're thinking about getting your own solar roof panels or are just doing some research for a project or special interest, then this article will help you out as it explains all of the solar energy pros and cons. It's no secret that domestic solar power is one of the fastest growing industries in the World right now. With cheap solar panels flooding in now from China the question is no longer are solar panels worth it, it's now a case of I'm definitely going to get them, what are the most efficient solar panels to get? This site has information on pretty much anything to do with domestic solar panels, so be sure to have a look around. Solar Energy Pros and Cons List - Pros There are two main advantages when it comes to solar energy. Most of the other pros are just extensions of these. The first major advantage of solar energy is that it produces NO pollution while making electricity. With Global Warming and rising prices for oil this one factor alone is the main driver of the global solar boom. Another advantage, closely linked to this, is the fact that rooftop solar panels are very low maintenance. Once installed, you don't really need to do anything more apart from some regular wiping and cleaning. The second major pro when it comes to solar energy is the fact that solar panels can produce electricity in very remote locations off the grid. There are a lot of practical applications for this such as people who live in the desert or other remote spots as well as the ultimate remote location of all; space. Solar Energy Pros and Cons List - Cons There is only really one major disadvantage of solar energy and that is the fact the solar panels can only produce energy when there is sunlight. Seems, obvious right? But lots of people don't take this into consideration when calculating how many solar panels for your home you'll need. All solar panel cost calculations should include actual insolation data (amount of daily sunlight) from the National Renewable Energy Laboratories website to really get an accurate estimation of your likely solar panels requirements. The other main disadvantage, which is actually becoming less and less relevant, is the cost of solar panels. Just a few years ago this was a major disadvantage because the only way you could get the best solar panels was through a franchise or licensed dealer. They charge ridiculously high prices for solar arrays and also make it so you have to use them for the installation as well, which increases the costs again because they give you no other choice. Now that the market has opened up, you can get direct access to cheap solar panels straight from the manufacturer and get them installed yourself either with a guide or a local contractor or electrician. Solar Energy Pros and Cons Conclusion As you can see the solar energy pros and cons list heavily favors the continued growth and expansion of solar energy worldwide. The renewable aspect of solar energy is strengthening each day as fuel prices rise and pollution worsens. Additionally, solar panels are losing their reputation for being expensive as people are becoming aware that solar panels are actually easy to buy and install yourself very cheaply. http://www.cheap-solar-panels.net/solar-energy-pros-and-cons.html 13 Sep 2011 03:09:06 GMT energy,environment,efficiency,home,diy neville@nevillepettersson.com Sunforce Solar This article is all about the low-cost domestic solar power manufacturer Sunforce. Sunforce is a relatively small private company with offices in North America, Europe and Asia. The company was established in 2005 and currently has around 50 employees. Sunforce is one of the many manufacturers to have operations based in China in order to offer cheap solar panels to the end user. It is precisely these sorts of companies which are helping to bring the cost of solar panels down, making it even more appealing for you to get solar panels for your home. Here at Off The Grid Homes, we highly encourage all American home owners to build your own solar panel system and by using products like those from Sunforce, it makes the job even easier and is getting cheaper by the day. Sunforce 12 Volt Battery Chargers Sunforce 50033 The Sunforce 50033 15 Watt Solar Charging Kit is one of the many solar panel 12v chargers produced by Sunforce and is also the most popular model. The range of 12v chargers from Sunforce are designed to power up your batteries when on the move such as when camping, boating, driving your REV or for your 'off the grid' cabin. When bought from Amazon the Sunforce 50033 charger comes with a 7 amp charge controller, mounting frame and wiring kit giving you everything you need. Some reviewers did find that there was some soldering required to terminate some of the wiring, which is a downside. Sunforce 50048 The Sunforce 50048 60 Watt Solar Charging Kit is the premier 12v solar charging model giving the most amount of power and capable of charging your 12v battery as well as you laptop, phone, camera,and any other small appliances that you run. One of the helpful solar panel reviews did mention that the PVC piping around the edges does become brittle over time due to sun damage. They did also mention that if you use a paint or protective coating on the PVC this should stop this from occurring. Sunforce 50022 The Sunforce 50022 5 Watt Solar Battery Trickle Charger is the smallest portable charger from Sunforce. It doesn't produce as much power as the other larger solar chargers, but the advantage of this unit is the price as well a the portability. It's cheap enough not to worry too much if it gets stolen or breaks and can be carried around and mounted very easily. Sunforce Charge Controllers Sunforce 60032 The Sunforce 60032 30 Amp Solar Charge Controller is the larger of the two solar chargers from Sunforce. A solar charger is important because it prevents your solar panels from over charging your batteries and other devices. Over charging can damage your batteries so a solar charger is quite important. The Sunforce 60032 unit can handle up to 500 watts of solar power so it's a good choice if you think you might upgrade or add-to your system in the future. Sunforce 60031 The Sunforce 60031 10 Amp Digital Charge Controller is great for if you just plan to run one or two panels. It's quite a bit cheaper than the 30 amp model and had received great reviews. http://www.cheap-solar-panels.net/sunforce.html 14 Sep 2011 04:02:02 GMT energy,environment,efficiency,home,diy neville@nevillepettersson.com Backwoods Solar Energy Backwoods Solar Energy has been in the business since 1984 and produces alternative power energy for the remote homes that are not catered by power lines. They are offering their free custom design services for your alternative energy system and free technical support after purchasing their products like solar panels. In fact, most of their staff have their own off-grid homes that generate its own electricity using their own products, so that they can cater to all your needs with expertise. Furthermore, they are also offering discounts and bargains for their products, such as the solar mounts and modules which costs $750.00 each. It has two sets of UPM-8X pole mount rails in which the rails are drilled for $64, small Kyocera modules, Kyocera 135 and 130, and Solar World 175 and 165. The rails are 107 inches; and you can drill it to other modules. Furthermore, all the modules are intact though they have some minor rust and paint or powder coat or galvanizing scratches; the structure and the welds are likewise all good. They are also adding new items, like Solar LED Desk (light standard compact everlites with eight white LED multi-purpose lamps) which is the newest type of lamp that has a longer lifetime. In fact, it is rated at 100,000 hours. You can charge it fully under the heat of the sun for six hours. It will turn on at dusk, lighten up your nights and shut off during dawn. You can gain more information about their products and solar panel reviews online; just visit their website at www.backwoodssolar.com Backwoods Solar Electric System Backwoods Solar Electric System is a home-based business located in 1589 Rapid Lightning Creek Road, Sandpoint, Idaho, USA 83864. It was founded in 1984 by Steve and Elizabeth Willey. In 1974, they installed their first off-grid system. Steve is an electronic expert who has adapted varieties of appliances for 12-volt operations. In fact, he has three cordless phone models, one of which has an answering machine that functions on 12v DC and a 900-Mhz model phone. Furthermore, they have varieties of appliances such as Light Emitting Diodes (LED) that offers major advantages for your lighting needs like lanterns and flashlights, and bulbs and fixtures for your cabin or off-grid homes. Solar modules work like your car's battery but you do not have to plug it into the walls; you just need to expose it to the sun. They also have fluorescent compact lamps which are very suitable for remote home areas to lighten up your nights. If you want the best solar panels in your home, you can get in touch with them at 208-263-4290, through their 24-hour fax number 208-265-4788 or by sending them an electronic mail at info@backwoodssolar.com Backwoods Solar Society Backwoods Solar Society is a catalog and an online business which provides their customers with off-grid and grid-tie services. Their technicians have and operate their own products with their wide renewable energy systems. It started as a home-based business in the year 1978 and was founded by Elizabeth and Steve Willey. They have been in the business for more than 30 quality years. Currently, Julie, Scott, Seqouya and David are the owners of the company. Backwoods Solar Electric is one of the major web-based and mail-order renewable energy businesses that once operated in a remote place. It has since relocated a few miles down the road. You can visit their website at www.backwoodssolar.com, or reach them via phone at 208-263-4290 or via electronic mail at scross@backwoodssolar.com. Backwoods Solar is located at 1589 Rapid Lightning Road, Sandpoint, ID 83864. Backwoods Solar Module Location Solar Module must be exposed to direct sunlight. This means that there should be no shadows from trees, buildings and wires; otherwise, it will cut its power. However, a 20-degree sunlight exposure will create 95% power; thus, you do not have to worry if you cannot aim it into direct sunlight. Since sunrise and sunset are natural daily routines of the sun, you need to consider the position of your solar module. You need to aim the module at noon time from 10 a.m. to 2 p.m. to power it up fully. Of course, it is powered by solar energy; thus, sunlight exposure is a must for your solar module to work. However, if you will expose it earlier or later than noon, it will take six hours to power up to its full level. Furthermore, during seasonal changes, you need to alter the position of the module. In summer season, you need to have the module face the overhead noon sun. During winter, tilt the module to face the sun's lower noon. Furthermore, you need to protect it from snow; just set it near vertical to south direction. http://www.cheap-solar-panels.net/backwoods-solar.html 19 Oct 2011 03:06:11 GMT energy,environment,efficiency,home,diy neville@nevillepettersson.com Solar Charger For Iphone 4 A solar charger uses the same principles of electricity as a standard electrical charger. But among other advantages of solar energy, here rather than drawing electricity from a wall socket, a solar charger uses an arrangement of solar cells to collect energy from the sun, and then convert that energy to electricity either for immediate use, or for later use as stored energy in a battery. Whether or not the right solar charger for you will need an internal battery will be determined by the type of devices you intend to charge and your intended use. Smaller devices, such as cell phones or digital music devices might run fine directly from the sun. However, larger devices may require a battery because of the power needed. While solar chargers without internal batteries are cheaper, one important consideration to note is that if the sun is not available when you intend to use the device, it will not work. Consequently, having an internal battery is much more convenient as the device can be run at any time, regardless of the level of sunlight. Solar chargers come in a wide variety of sizes and power output capabilities. Some are designed to be larger and mainly for running household devices and appliances. These come in the form of solar powered generators for the home. Others are designed to be compact and easily portable. For example, we all love the convenience of being able to run many of our portable electrical devices from batteries when we are not close to conventional wall sockets. Fortunately, that type of convenience also applies with regard to solar powered portable devices. It is crucial, though, to correctly match the solar charger you are considering to the types of devices you intend to run for power requirements. To compare, with standard batteries for portable devices this is an easy process with which we are all well familiar. Everyone knows that to run a portable stereo (boombox) you will probably need several D-cell batteries, while to run a small flashlight you might need only a couple of "AAA" batteries. However, with solar power these distinctions are not as obvious, and so it might be a good idea to familiarize yourself with some of the terms used to describe the power output of chargers and the needs of devices. Here are some basics: The three main electrical units you are likely to encounter in your shopping comparisons are watts, volts, and amperes (amps). A common analogy used to describe the relationships between these is that of a garden water hose. Volts would represent the water pressure of the water coming out of the hose, amps would be the rate of flow of the water, and watts would be the total power or strength of the water coming out. Watts equals volts multiplied by amps. So, for example, if you increased the water pressure (volts) then the flow rate of the water (amps) would also increase. Consequently, when both of these numbers are higher, so is the water power produced (watts). For our purposes, then, we need to know that the most important unit is watts. We need to know how much power (watts) our device needs to run, and we need to know how much power our charger can produce. The other unit we will consider is amps. Once we are satisfied that our charger is powerful enough to run a given device we can also look at the flow rate of electricity (amps) and that will tell us how long the device will run on a single charge. This can be a little confusing at first, but the important thing is if these questions are not answered in a description of the charger it is always a good idea to find out. Through common experience we are all reasonably familiar with about how long a regular dry cell battery will last in a given device. However, most of us do not have that same experience with solar energy. That is why it's a good idea to have all the information about power and how long it will last before we make a purchase. Solar Charger USB Another handy feature of the portable solar charger is that not only can it draw and store energy directly from the sun, but when the sun isn't available many models have the capability of connecting directly to your home computer for charging via USB (universal serial bus) connectors. (of course, for mobile use the solar charger used must come with an internal battery.) One important thing to remember here is that you should always have the proper connectors with you at the time of need. This includes both to connect the solar charger to the computer and to connect the charger to the device later. Some mobile devices have USB ports and some do not, so you might need a different cord to connect them. This is an added benefit to the solar charger since it can be used as a power source without actually needing any sunlight. Solar Charger For Iphone, Ipod, Ipad, Laptop Some of the most common mobile devices that use stored battery power are Iphones, Ipods, Ipads, and laptop computers. Depending on what you have, you may have the need to charge any or all of these products and may wish to use a solar charger. It could be easy to assume that one charger could handle all of these devices, but that might be very far from the truth. Again, it is absolutely critical that you match your charger to the devices you are using. While the general size of a device can be a loose guide as to how much power it needs, by no means is it conclusive. In many, many cases two devices of approximately the same size have different power requirements such that a given charger will work with one but not the other. For this reason it is always a good idea to make sure a given charger is specifically rated to charge your specific device. Many chargers advertise that they are "great for Iphones" or some such. Just make sure that if what you have is instead, say, an Ipod that it will also work for that. As you might imagine, laptops use much more energy and need more power to run than the smaller devices. Therefore, you will need a larger solar charger. Fortunately, these are still very convenient because today laptop flexible solar panels can come in the shape of a rolled up newspaper. Just roll out the panel wherever you are and let the sun start storing energy to power your laptop. Of course these larger solar chargers do cost more, but the good news is that because of their power ratings you may be reasonably confident that one laptop charger may also be able to charge all of your other small mobile devices. The only extra thing is that you might have to make an adjustment for voltage as laptops sometimes have different needs. Many appropriate solar chargers come with a switch to make this easy. Again, double-check that the solar charger you are considering will power all of the devices you intend, and for an amount of time that works for you. http://www.cheap-solar-panels.net/solar-charger.html 25 Oct 2011 01:12:25 GMT energy,environment,efficiency,home,diy neville@nevillepettersson.com Solar Panel Efficiency Temperature In order to determine which is the best solar panel system, one of the most important considerations is the efficiency of the system. Simply put, the efficiency rating of a panel system approximates the percentage of sunlight that hits a solar panel that is converted into electricity. Or, an efficiency rating could be applied to the percentage of the sun's energy that is converted into usable heat, but most often the term "efficiency" is applied to conversion to electricity. One of the main applications of the efficiency rating is for space considerations. Naturally, the higher efficiency panels, such as monocrystalline solar panels, will take up less space. There are many factors which can affect the efficiency of solar roof panels, and these include the age of the panels, the temperature, electrical wiring resistance, the tilt angle of the panels, and spectral distribution. Most of these are self evident, however, spectral distribution refers to the warping effect our atmosphere has on sunlight. For precise measurements it must be taken into account that "pure" sunlight does not actually reach earth (in comparative terms). It is first "filtered" by the atmosphere to varying degrees based on what the solar panel is made of. Credit should be given to those solar panel systems which have higher efficiency due to this filtering. While you are evaluating different solar panel efficiency ratings it is absolutely essential that you compare the same type of rating. The two most widely used rating systems are "STC" and "PTC". "STC" stands for Standard Test Conditions and is the rating system established by solar manufacturers. They measure solar panel efficiency under uniform sunlight, tilt angles of the panels, air mass and temperature conditions. Here, "air mass" just refers to the filtering effect of the atmosphere described above. The technical specs for the STC rating are 1,000 Watts per square meter solar irradiance, 25 degrees C cell temperature, air mass equal to 1.5, and ASTM G173-03 standard spectrum. The actual rating number represents the average number of Kilowatts of output per day. In contrast, the "PTC" rating refers to PVUSA Test Conditions. These resulted from the Photovoltaics for Utility Scale Applications project, which was begun in 1986 and is a joint venture between Pacific Gas & Electric, the Department of Energy and other utilities across the USA. The technical specs for the PTC rating are 1,000 Watts per square meter solar irradiance, 20 degrees C air temperature, and wind speed of 1 meter per second at 10 meters above ground level. The PTC rating number also represents the average number of Kilowatts of output per day, and without getting into a huge analysis, just know that it is generally believed that the PTC is a better and more precise rating system. This is because the PTC testing conditions are considered to be more reflective of "real world" solar and climatic conditions. In addition, the PTC rating also takes into account the inverter. Consequently, the PTC number will be lower than the STC number. While PTC is preferable, always make sure that whatever numbers you have available for comparison are based on the same rating system. Counter-intuitively, an increase in air temperature actually decreases a solar panel's efficiency. The reason for this is somewhat complex, but we begin by noting that as the temperature increases, the conductivity of the solar cell material also increases. This, in turn, will cause the electrical charge within the solar cell material to balance out. When the charge balances, that makes charge separation more difficult. And when charge separation is made more difficult, the voltage across the cell goes down. Voltage is akin to water pressure in a hose, so if that goes down then less water comes out, or here, less electricity is produced. Now, to be fair it should be noted that an increase in temperature does cause an increase in the mobility of electrons, which causes the amperage (flow of current of electricity) to increase. That means more electricity, but this increase is much more than offset by the aforementioned decrease in voltage. In fact, it has been estimated that solar cell efficiency goes down by about 0.5% (in crystalline cells) for every degree centigrade the temperature rises above 25 C (77 degrees F.). So, as you can see those who live in climates that frequently reach temperatures above 25 C should be aware of this effect. Fortunately, there have been a great number of solar panel efficiency improvements over the last several years, and many more are doubtless on the way. A short survey of some of them would have to include mention of so-called "concentrator systems". These systems increase the light intensity by using concentrating optics. Higher intensity light per amount of space increases the efficiency of the cell, especially when they are now-cost-effective GaAs cells. Another improvement in efficiency has come with the use of multijunction cells. These contain several layers of silicon, with each layer tuned to capture different light frequencies. Extracting energy from multiple light frequencies maximizes the production of energy from each solar unit of light coming from the sun. These are among the most efficient solar panels available. And while these are super efficient, they are also very expensive, so before we see them on a mass scale further developments will have to be made to bring the price down. One of the latest and most exciting innovations has come in the form of what are called "microinverters". In a typical solar panel system, the inverter is what converts the DC power generated from the sun's energy into AC electricity for use inside the home. Until now, the technology has been to have one inverter for the entire system, and then have cords running from each panel to the inverter for power conversion. With the microinverter, though, each panel has its own mini-inverter. This will not only greatly reduce the cost of having to run so many cables back to a single inverter, but it will also increase the efficiency. Since each cell will have its own attached microinverter, the electricity will not have to travel back to a single standard inverter. This increases efficiency because the longer electricity has to travel the more power will be lost due to resistance. Finally, perhaps one of the more unusual efficiency developments in recent times involves the use of "building integrated PV", also known as "building-applied PV". With this approach, instead of attaching solar panels to building structures, the buildings are actually partially made of the solar panel materials themselves. At first, this will more commonly be seen on such things as skylights or facades, in addition to certain types of roofs. It is easy to see the potential for enormous savings in the cost of the regular building materials no longer needed, along with the extra power generation of the solar panels, which will be able to cover a much wider area and generate even more electricity. http://www.cheap-solar-panels.net/solar-panel-efficiency.html 27 Oct 2011 03:10:24 GMT energy,environment,efficiency,home,diy neville@nevillepettersson.com How To Build Solar Panels Perhaps you live in some remote place, off the electrical grid, or you'd like to save a little money, or you wish to be ecologically friendly. You tried a wind turbine, except the wind doesn't blow when you want it to. You tried a biomass gasifier, but after escaping major injury during the welding and metal-working stages, your creation produced a sticky, thick, black mass which stank to high heaven. You tried an exercise bike connected to a dynamo, but got tired. At this point, it is time to contemplate the building of a solar panel. The cost would deter most people from purchasing one. Where To Get Solar Cells A solar panel is a collection of solar cells, the things which actually transform sunlight into electricity. The greatest hurdle to overcome in building a solar panel is the cost of solar cells. Bought new, they are very expensive, and are sometimes hard to get hold of in quantity for any price. But blemished or outright damaged solar calls can be found on Ebay and elsewhere at a fraction of the price of perfect, new cells. These can be employed to create a solar panel which works just fine. What Kind Of Solar Cells Should You Buy? Bricks of 36 mono-crystalline solar cells arranged 3 x 6 x 2 and wired in series will produce around half a volt each, providing 18 volts in total. This is enough to charge a 12 volt battery. This kind of solar cell is as thin as paper and as fragile and brittle as glass, so it is easily damaged. The cells are coated in wax to allow for shipment, and this is something of a pain to remove. Removal can be achieved by means of a bath in hot water (“What are you cooking, darling?” “Oh, solar cells”). The water should not be boiled, or the bubbles will collide with the cells and the electrical connections of the cells may be affected. Placing the bricks in the water while it's cold will avoid a harsh, thermal shock. So, Should You Get Unwaxed Cells? If you can find a source which provides unwaxed solar cells, you will save yourself much bother, although this must be traded-off against the increased risk of damage during shipping. Solar cells which rattle around in their box can get chipped at the edges and on the corners, but minor chips won't affect cell output in a significant way. Hey, they were factory seconds or otherwise blemished, anyway, and this was usually because they were chipped. A Couple Tf Other Considerations Using solar cells without metal tabs attached doubles the amount of soldering to be done, so it's worth paying a little more for the tabs. Using different cell sizes is a bad idea because the current produced will be limited by the size of the smallest cells, and larger ones won't work to their full capacity. This will mean yours is not one of the most efficient solar panels. Put Them In A Box Put your solar cells into shallow box whose sides won't block sunlight which comes in from an angle. In this case, the box is 45.75 x 22.25 x 0.75 inches. A few coatings of paint inside and out will protect the wood. Painting both sides is necessary, or the paint will curl, and this can damage the solar cells which are glued to it. Vent holes will equalize air pressure and permit moisture to escape. The vents should be on the bottom to prevent water from entering. Holes of at least a quarter of an inch wide work. Some fiberglass insulation will prevent dust and critters from getting in. A plexiglass front will provide protection from the weather. Glass will do the job, but is so very fragile and can be shattered by flying debris. In this way, you will attain the honorable goal of domestic solar power. http://www.cheap-solar-panels.net/how-to-build-solar-panels.html 31 Oct 2011 10:22:56 GMT energy,environment,efficiency,home,diy neville@nevillepettersson.com What Is Solar Power? "Solar power" is the conversion of the abundant energy of sunlight into a form that can be used for purposes sunlight doesn't serve directly. The most common meaning of the term involves the conversion of sunlight into electric power, through the use of solar panels normally, and that's what will be discussed here. Advantages of Solar Power The amount of energy from the sun is enormous, and it flows continually in abundance whether we make use of it or not. Less than one part in 8,000 of the sunlight striking the Earth could supply all of the energy needs of the entire population of the planet. Solar power is also free to use, inexhaustible, and non-polluting. It's adaptable to all energy uses, both large and small. The cost of photovoltaic cells and other components of solar power systems is falling rapidly as the technology progresses. At the same time, the cost of fossil fuel energy is expected to rise dramatically due to the effects of "peak oil" and of increasing global demand. For this reason, solar power presents increasing economic advantages along with its abundance and environmental benefits. How do Solar Panels Work? Solar panels are collections of photovoltaic cells that convert sunlight directly into electricity. Photovoltaic cells are constructed of semiconductors such as silicon (the most common material used). When sunlight strikes a semi conductive material such as silicon, a part of it is absorbed by the material, and the process of this absorption energizes electrons within the material, some of which are freed to flow as current. Metal contacts placed at the ends of the photovoltaic cell allow the current to be drawn off and conducted away for use. The result: solar power! A solar panel is made of multiple solar cells that together generate a flow of power usable for various purposes, such as to power a home. Solar panels are measured in wattage and also in area or square inches of surface. Solar Power For Home Use How much area of solar panel would be required to provide solar power for a typical house? That depends on how much power the home uses, which varies depending on the size of the home, the energy efficiency, and what type of appliances are in use. It also varies by where you live; a home in southern Arizona receives more and more dependable solar power than one in northern Minnesota. A typical home that does not use electricity for heating or air conditioning and is not particularly energy-efficient might use between 10,000 and 15,000 watt-hours per day. To produce that much power in an area where a solar array generates 70 milliwatts per square inch in full sunlight would require a rooftop solar system consisting of 285 square feet of solar panels, or about a 16' x 16' array. Of course, if someone were using solar power to partially reduce energy consumption from the grid rather than to achieve complete self-sufficiency, a smaller array would be sufficient. But it's easy to see that the main expense of solar power is in the initial cost of materials and construction rather than in any ongoing costs such as fuel. Building one's own solar panels and installing them oneself can significantly reduce this cost. On Grid or Off Grid? A home solar power system can be designed either to be "on-grid," which means the home is still connected to the local electric utility and runs on a mix of solar power from the array and conventional power, or "off-grid," which means the home runs on solar power from the home array completely. In either case, a battery is normally used to allow use of the system during times when the sun isn't shining. http://www.cheap-solar-panels.net/what-is-solar-power.html 02 Nov 2011 02:56:29 GMT energy,environment,efficiency,home,diy neville@nevillepettersson.com