Home Solar Power

Private solar installations are really taking off nationwide. In just two years, (about the same length of time it takes to get a pair of 250 MW solar power plants approved in California, for example), homeowners and businesses have added that much power to the Californian grid, just from individual rooftops throughout the state. Read More….

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A solar inverter (photovoltaic inverter)  is a type of electrical inverter that is made to change the direct current (DC) electricity from your solar panels or wind turbines into alternating current (AC) for use with home appliances. Some inverters are designed to be connected to the power utility company’s grid.

Three Basic Types Of Solar Inverters

Stand-alone inverters: Used in independent solar energy systems or any energy system that is completely off the grid. The inverter is designed to draw  DC energy from batteries charged by solar panels or wind turbines, and change it to AC power.

Most stand-alone inverters also incorporate integral battery chargers and charge controllers to replenish the batteries. The charge controller regulates the input from the solar panels, regulates the battery output, and handles charging the batteries. Normally these do not interface in any way with the utility grid.

Grid Tie Inverters: Many solar inverters are designed to be connected to a utility grid and they contain special circuitry to precisely match the voltage and frequency of the power supplied by the utilities grid.

The inverter takes the electricity generated by your renewable energy system and sends it to the power distribution panel, from there the power may be used by  appliances within your home, or if not needed it will redirected to the utility grid.

This redirected energy is used by the other utility customers, and you receive some form of compensation for putting excess power into the grid. When there is no energy generated, utility power is pulled from the grid to provide power to your home.

Grid-tie inverters are designed to shut down automatically for safety reasons as required by law, upon the loss of the utilities power supply to protect the utility workers who are repairing the system.

Battery Backup Inverters: These are special inverters which are designed to draw energy from your battery bank, manage the battery charge via an on board charger and charge controller. The DC power is converted to AC power for your appliances and they export excess energy to the utility grid.

Unlike a standard grid tie inverter, these inverters are capable of supplying energy to your home during a utility outage, and are also required to disconnect from the grid during power outages.

No matter what type of system you use, an inverter is an integral part of it.

Here is a video, keep in mind that a small home system will be less complicated.

Find out what incentives your state offers in tax credits, state rebates, utility rebates, and more.

DSIRE is a comprehensive source of information on state, local, utility, and federal incentives and policies that promote renewable energy and energy efficiency. Established in 1995 and funded by the U.S. Department of Energy, DSIRE is an ongoing project of the N.C. Solar Center and the Interstate Renewable Energy Council.

Learn more HERE

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Thin film solar cells are a rapidly advancing alternative and solar energy technology. A new development comes from  Konarka, maker of a unique solar plastic called Power Plastic.

Its patented photovoltaic material, called Power Plastic, is more efficient than even the best thin-film systems devised by the likes of  First Solar and Solyndra. It is lightweight, portable, and perhaps most importantly, flexible — making it suitable for a host of interesting applications ranging from rooftops to apparel. Read More..

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• Thin Film Solar Cells Simplified

Basic Solar Cells

A solar cell is a photovoltaic cell that is used in solar applications. Photovoltaic cells rely on substances known as semiconductors. Semiconductors are insulators in their pure form, but are able to conduct electricity when combined with other materials, (called doping).

A photovoltaic cell joins n-type (negative) and p-type (Positive) materials, with a layer in between known as a junction. The suns energy knocks electrons loose, which will want to flow freely between the positive and negative field. Contacts at the top and bottom of the cell allow the electrical current to be drawn off and used.

Traditional Solar Cells

Monocrystalline: Silicon is made from very pure silicon which has a single and continuous crystal lattice structure with practically zero defects or impurities. monocrystalline silicon is superior to other types of silicon because of their their high efficiency compared to other manufactured types.

The manufacturing process required to produce monocrystalline silicon is more involved and detailed than other types, this results in slightly higher costs than other silicon technologies.

Polycrystalline: also referred to as Multicrystalline: Silicon is made from multiple small silicon crystals rather than a single one. While solar cells based on monocrystalline silicon deliver better performance than polycrystalline silicon, some people believe that the it may become the mainstream material for solar cells due to its lower cost.

Both of these are cut into silicon wafers which are then processed. They are likely to be around for a long time, conventional silicon manufacturing technology has continued its steady improvement year by year and its production costs are still falling.

Thin-film Solar Cells

If you’ve used a solar-powered calculator, you’ve seen a solar cell based on thin-film technology. Clearly, the small cell in a calculator is not big and bulky. Most are about an inch  long, a quarter-inch (0.6 cm) wide and very thin, the thinness of the cell is the defining characteristic of the technology.

Unlike silicon wafer cells, which have light-absorbing layers that are traditionally 350 microns thick, thin-film solar cells have light-absorbing layers as small as one micron thick. A micron is a unit of measurement equal to one millionth of a meter, and is is 0.000039 of an inch.

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, still silicon, but in a different form, or the polycrystalline materials cadmium telluride (CdTe) and copper indium (gallium) diselenide (CIS or CIGS).

Amorphous silicon is a non-crystalline form of silicon and it is the most well developed thin film technology to date. An interesting new thin film technology under development involves the use of microcrystalline silicon, seeking to combine the high efficiency of crystalline silicon with the simpler and cheaper thin film technology of amorphous silicon.

Cadmium telluride (CdTe) is a crystalline compound formed from cadmium and tellurium. There are health concerns with the use of cadmium in thin film solar cells. Cadmium is a highly toxic substance that, like mercury, can accumulate in food chains.

This is a blemish on any technology that is part of the green revolution, although researchers are currently investigating cadmium free thin film solar cells. Many of these technologies are proving themselves to be just as efficient as those that require cadmium

Copper indium gallium selenide (CIS or CIGS) is the newest generation of thin-film cells that uses thin layers of copper indium gallium deselenide (CIGS). In the lab, CIGS solar cells have shown the highest efficiency of any thin-film cell, even exceeding that of some types of silicon cells made today, but it will likely not reach this level of efficiency in mass-produced cells.

The challenge has been to reliably make thin-film solar cells on a large scale, with even a minimum level of efficiency needed to compete with other types of solar cells.

P-I-N And N-I-P Devices

Like other solar cells a three-layer sandwich is created, the difference being  thin film technology uses an intrinsic (i-type or undoped) layer between the n-type  and  p-type layer. This sets up an electric field between the p- and n-type regions that stretches across the middle intrinsic region, which channels the electrons.

For p-i-n thin film solar cells there is a p-type layer (p), an n-type layer (n), and an intrinsic (i) layer between the two. A n-i-p has  an n-type layer, a p-type layer, and an intrinsic layer between the two.

While thin film cells have been around for over twenty years it is still considered new and is still being developed. There are systems that are currently using this technology today.

Thin film can actually be made of flexible materials, some of the new developments are ink like material being ‘printed’ on to thin sheets, and solar shingles. Monolithic integration which is the automatic built in connection of individual solar cells are being developed to reduce manufacturing costs, by eliminating expensive labor for manual connections.

While thin film cells look very promising it is new technology and has not been proved in the long run compared to methods available now, which should last for around 20-25 years.

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Basic Information

Solar cells (photovoltaic cells) are joined together in a series and put into a container to make a solar panel. Multiple Solar panels working together are a solar array.

A single photovoltaic cell, called a solar cell when used to harness the suns energy, does not create a lot of electricity. A single cell produces a voltage of approximately 0.5 volts, so cells are joined together in a series.

The more solar cells in a solar panel and the higher the quality of the
solar cells, the more total electrical output the solar panel can produce.
The conversion of sunlight to usable electrical energy is known as the Photovoltaic Effect.

The panel has a non reflective glass top made of tempered glass which is much stronger than normal plate glass, and they are completely sealed to protect them from humidity and the elements. One square meter of solar panels can produce up to 150 watts of maintenance-free power for 20-25 years

The 3 Basic Types Of Solar Panels

Monocrystalline cell : The most efficient and expensive solar panels are made with monocrystalline cells. Pure silicon is used to grow a single crystal in the shape of a long silicon rod. The rods are then cut into thin wafers of .2 to .4 mm thick, and are processed to make individual photovoltaic cells.

Polycrystalline or Multi-crystalline cell : Polycrystalline cells are a little less expensive and slightly less efficient than monocrystalline cells. The silicon is not grown in single crystals, but in a block of many crystals. This gives them a shattered glass appearance, they are then sliced into wafers and processed.

Amorphous cell : These are not really crystals, but a thin layer of silicon deposited on a base material to create the solar panel. Amorphous solar panels are much cheaper, but their energy efficiency is also much less so more square footage is required to produce the same amount of power as the mono or Polycrystalline type of solar panel. They can be made into long sheets of roofing material to cover large areas of a south facing roof surface.

Volts x Amperes = Watts

To get the general idea of volts and amperes, imagine two vehicles on the same road traveling at the same rate of speed, call that speed the ‘voltage’. One of the vehicles is a car the other a truck, the truck carries twice as much as the car so call that double capacity the ‘amperes’.

They are both traveling at the same rate (same voltage) but the truck is carrying more (amperes). A panel that produces 2 amperes sends twice as many electrons (electricity) as a one-ampere panel. For solar panels what you want to know is the watts (their power).

Simple multiplication will give you the answer. Connecting in series raises the voltage. Connecting in parallel raises the amps.

A 12-volt panel producing 2 amps of current has 24 watts of power (2 times 12).

If you take two of these (12volt) 24 watt panels and connect them in series it will add to their voltage, with no change in amperage, the result is 24 volts at 2 amps, 24 times 2 = 48 watts.

The same two panels connected in parallel results in the voltage staying the same but the amps are doubled, 12 volts at 4 amps, 12 times 4= 48 watts.

Knowing your voltage, amps, and watts helps you plan your entire system.

Mounting The Panels

Face the panels true south (not magnetic south). Try to position your solar array directly under the noontime sun, so sunlight hits them at a 90%  angle for maximum efficiency. Trace the path of the sun in the sky to determine if an object is casting a shadow, remove it if possible, and trim any branches that may be blocking sunlight to your solar unit.

Fixed mounts: Unmovable, you can decide to leave it at the best angle for the winter to help even out seasonal performance. It is advisable to have at least a 15° tilt to avoid rain accumulating on your panels. A greater angle will also help keep them free of snow.

Adjustable mounts: You can adjust your panels position manually to get the best tilt angle for each season. Take your latitude and add 15° for the winter, and subtract 15° for the summer to compensate for the suns position. At the spring and autumn equinoxes, the best angle is equal to your latitude.

Tracking mounts: Tracking solar panel mounts follow the path of the sun during the day to maximize the solar radiation that the solar panels receive, they are the most efficient type.

However they are very expensive and can break down or freeze up in the winter. An option is to just add two more fixed panels to make up for the 20 to 30 percent gain and save yourself a lot of money.

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How Solar Cells Work

Solar cells are all photovoltaic cells. Photovoltaic, as the word implies convert light into electricity (photo = light, voltaic = electricity). The term solar cell is reserved for devices that convert the suns energy into electrical energy, also called solar power, while the term photovoltaic cell is used when the light source is unspecified.

Semiconductors-Silicon

Solar cells are made of special materials called semiconductors such as silicon, which is currently the most commonly used. Pure silicon is a actually a poor conductor of electricity because its electrons are  not free to move about. The electrons are all locked in its crystalline structure, unlike good conductors like copper where electrons can move more freely.

N-type And P-type

Impurities are added to the silicon, other atoms mixed in with the silicon atoms to make it a much better conductor than in it’s pure form, changing the way electrons flow in it.

The process of adding impurities on purpose is called doping, and when doped with phosphorous, the resulting silicon is called N-type (“n” for negative).

When silicon is doped with boron, it becomes P-type silicon (“p” for positive). A positive and negative field is necessary for an electric current.

The P-N Junction

A solar cell has three layers necessary for energy conversion, a top junction layer, made of an N-type semiconductor. A middle layer which is the core of the device, this is the absorber layer (the P-N junction). And a bottom layer made of a P-type  semiconductor.

The Basic Construction Of Solar Cells

The top layer has some type of electrical conductors attached and needs a careful balance of electrical contact surface area and light collection surface area. Some solar cells overcome this problem with transparent conductors, but this is very expensive and few employ such a technique.

The top is covered with a non reflective covering (giving them the blue colour), the bottom of the cell also has a conductive surface, which has no size limitations.

The Process

When light strikes the cell the absorbed light is transferred to the semiconductor. The energy knocks electrons loose, allowing them to flow freely between the positive and negative field. At the junction the electrons can only move in one direction creating a negative charge at the top and a positive charge at the bottom.

Similar to a battery with a positive and negative terminal, with the placement of metal contacts on the top and bottom of the photovoltaic cell we can draw that current off to use externally for whatever application is needed.  When you connect a series of solar cells together you have a module, better known as a solar panel. That’s the basic process of solar cells simplified.

Free Power From The Sun

Solar cells perform the electrical conversion free, without moving parts, noise, pollution, maintenance, or radiation. On a bright, sunny day, the sun shines approximately 1,000 watts of energy per square meter of the planet’s surface.

Adding solar panels to an existing home can be expensive, but there are alternatives. There are many solar power kits available at a lower cost
or you can just make your own. Recently many people have turned to building their own solar panels, solar cells have become inexpensive, and an ambitious diy enthusiast can make their own solar panels at a surprisingly low cost.

Solar Power Information

Harnessing the power of the sun is on the rise and has lead to many different uses of solar power.

Most electric Power today is generated by turbines, using principals discovered by Michael Faraday in 1831. Most of these generating plants use the process of burning coal to power the turbines.

The Burning Of Coal

The burning of coal is one of the largest sources of carbon dioxide and other pollutants in this country and is a major contributor to global warming.

Economic concerns dictate that these plants will be around for many more years, as society is so dependent on electric power, that without it there would be chaos.

Solar Energy

Energy from solar power advanced rapidly during the space age as it was a great method for powering satellites.

Solar power is slowly growing in popularity, especially when used as a means to power your own household, giving you a free source of energy that is non polluting.

This reduces the strain on the public power grid, and it gives you the satisfaction of knowing that you are helping the environment.

You are also helping your wallet by eliminating the dreaded monthly power bill, which has grown into a large expense and will continue to get larger in the future.

The Different Uses Of Solar Power

Interestingly solar power has other uses besides generating electricity, for instance it can also be used to cook food. Solar cookers are more of a novelty, but they actually do work well and show another of the different uses of solar power.

Solar heating systems at home are being used by some families to take care of their own home’s heating needs. Solar thermal systems can maintain a steady temperature at your house without worrying about bills.

These systems are currently in use and have proven to be a valuable resource to many people. Just one more of the many uses of the power of the sun.

The use of solar energy to power traffic signs, emergency roadside phones, and other similar applications has been growing in popularity lately. There are many marine applications like the powering of remote buoys for example.

Solar power is being used in japan to charge electric vehicles, there is an interesting article on this at the green autoblog, and a similar station has just been opened in Brooklyn NY, article at brooklynpaper.com

Of course the use of solar power in communication satellites has made today’s cell phones and other related applications possible.

Solar Power For Your Home
There are many people who have always wanted to eliminate their power bill and help the environment but the very high cost has understandably held them back.

Recently new developments in the solar energy field has made it possible for just about anyone to have their own solar powered home. You can have a professionally installed system, buy a kit and install it yourself, or build an entire system on your own.

Thousands of people have actually built their own solar systems at a very low cost, using materials that are readily available just about anywhere.

Which ever option fits your needs, of all the different uses of solar power, home solar systems is your best bet to reduce your power bill and to help reduce pollution.

Home Solar Power

Using home solar power systems will help the problem of decreasing oil supplies. This country is facing a serious two headed energy crisis.

First off is the use of fossil fuels. The problem with this is the ever increasing prices, and the dependence on having to get these resources from overseas suppliers that can shut off the supply at any time.

Will Oil Run Dry?

Contrary to popular belief there are tremendous petroleum resources still available in this country, like oil shale and oil sands for instance. That being said, the process of extracting usable oil products from these resources is extremely complicated and very expensive.

So while oil is probably not going to suddenly run dry, decreasing supplies of relatively cheap oil only means increasing prices of the harder to get resources.

For families already struggling to get by this is not a good prospect, and for those that think this is in the future, you only need to look back a short time to when oil prices took a huge jump. And this is just the beginning, ever higher rising prices are inevitable.

Pollution And Oil

The second problem and the one that is considered the worse of the two is pollution. Bad air quality and the threat of global warming is real and it is not going to go away as long as the burning of fossil fuels continue to add to the problem.

This country has been dependent on this form of energy for the last 150 years. Initially people were not aware of the consequences, but we now are beginning to realize what they are.

Unfortunately this form of power is deeply entrenched and will be around for a long time. Additionally the government has been slow to react and make any changes, even with the knowledge of increasing pollution. That means it is has been left up to the individual person to act.

The Abundance Of Solar Energy

The sun’s energy or solar energy is the most abundant form of energy available on earth, it is time to take advantage of it. What most people do not realize is that switching to solar power has now became affordable to everyone. There are three options:

• Build Your Own. Solar cells have became quite inexpensive lately, using these and materials that are readily available at your own local home store you can make your own home solar power system. These home solar systems are not only cheap to build, they are very reliable, low on maintenance, and are a great investment for your homes power supply. With a good manual they are surprisingly easy to build.

• Purchase A Kit. Everything you need delivered to your home. Like homemade project, only much easier to put together, as all the measuring and cutting has been done for you. They are also very reliable, low on maintenance, and easy to assemble, but do cost substantially more than a do it yourself project.

• Professional Installation. Sit back and let a reputable company do all the work. More and more home solar power companies are converting homes to solar energy. The cost associated with this plan is quite high, but if you can afford the cost it is a great option.

With decreasing oil supplies and increasing pollution, the time has come to not only help the environment but to reduce, or even end your monthly power bills. Convert to home solar power today.

A diy solar panel project is surprisingly easy and inexpensive to do. It is well within the reach of an ambitious do it yourself enthusiast, I have included some interesting information at the end of this post.

A photovoltaic cell is a device that converts light directly into electricity by the photovoltaic effect. When they are used for home solar power projects they are called solar cells. Photovoltaic cells in homemade solar panels are made of special materials called semiconductors like silicon, which is currently the most commonly used.

Photovoltaic cells are becoming more common everyday and are widely available and inexpensive to buy, and they are being used in hundreds of different applications. Satellites use photovoltaic cells for their power and were directly responsible for the development of inexpensive and effective solar cells for use in solar panels.

The Power Of The Sun

On a bright, sunny day, the sun shines approximately 1,000 watts of energy per square meter of the planet’s surface, and if we could collect all of that energy we could easily power our homes and offices for free.

Today’s solar cells available for home solar panel projects are around 15-20% effective, the reason that they are more effective is because the sun puts out a very wide spectrum of light and a photovoltaic cell can not capture the entire range of light the sun produces. That being said the amount of power a cell produces is easily enough for an entire families need.

Some Advantages Of DIY Solar Panels
* Easy to build.
* Free power.
* Good for the environment.
* Cheap to construct.
A single solar cell does not make a lot of power, but when they are connected together their power multiplies, put the connected phovoltaic cells in a module, and you have a solar panel.

Why pay thousands? A diy solar panel project can be done very cheaply. You need a good manual for the instructions, which will teach you how to connect the cells and how to make a weather proof container. From there it is just a question of doing the wiring.

Our recommended manual has easy to understand step by step instructions complemented with video instructions to guide you along on your project, and to make everything very clear and understandable. I have included some screen shots from some of the videos, sorry I do not have the right to show the whole video, but here is the link to the main website.

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