Home Solar Power

Basic Function

The basic functions of a controller are quite simple, they prevent battery overcharge and block reverse current to prevent electrical current from flowing out of the batteries.

Overcharging batteries will at the least significantly reduce battery life and at worst damage the batteries to the point that they are unusable.

A charge controller is needed in virtually all solar power systems that utilize batteries. While the basic function of a charge controller is simple they might well be the most complicated part of the whole solar electric system.

Different Types

There are different types of controllers,  basic charge controllers are very simple on or off systems.  Pulse width modulation (PWM) and maximum power point tracker (MPPT) technologies are more electronically sophisticated, adjusting charging rates depending on the battery’s level, to allow charging closer to its maximum capacity.

How They Work

A simple or basic charge controller simply monitors the battery voltage stopping the charging when the battery voltage rises to a certain level, and restarting when it drops to a certain level. Inexpensive but they are inefficient and old technology.

The more modern PWM charge controllers are a type of charge controller that slowly reduces the charging current to avoid overheating the battery after it has reached the regulation setpoint.

At the same time, the system continues to send the highest amount of energy over the shortest period of time , which results in rapid charge and high efficiency.

This type of controller allows the batteries to be more fully charged with less stress on the battery, extending battery life. It can also keep batteries in a fully charged state (called “float”) indefinitely.

MPPT is the top of the line charge controller in the market. The MPPT is a high frequency converter that takes the DC input from the solar panels, changes it to high frequency AC, and converts it back down to a different DC voltage and current to exactly match the panels to the batteries.

It tracks the input power from your solar array and the voltage from your battery bank and adjusts the voltage for the highest amp output to the battery bank.

PWM And Mppt Chargers

The Mppt controller is capable of taking a higher voltage and ‘down converting’ it to a lower voltage while ‘up converting’ the amps.  Simply put, say your solar panels have an output of 24 volts and 5 amps and your battery bank is at 12 volts.

The Mppt will ‘down convert’ the voltage from 24V to12V and while doing this it will ‘up convert’ the amps to 10 amps. So you would have 12 volts and 10 amps to the batteries resulting in a more efficient system.

The PWM controller using the same system will take the higher voltage and ‘down convert’ it to a lower voltage but there is no up converting. So a simple way to look at it is you lose half the volts and half the amps, remember that the Mppt controller uses these down converted volts to double the amps.

MPPT charge controllers offer a potential increase in charging efficiency up to 30 % but of course they are much more expensive. Both systems work well but even at the higher cost MPPT charge controllers are best for your system.

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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• Solar costs set to plummet 50% by year’s end (green.venturebeat.com)
• Plans for solar power from outer space move forward (dailyfinance.com)

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A “grid-tie” solar energy system is designed to sell power back to the utility company and can be used with or without batteries.

Batteries Or No Batteries

If you are using batteries the power generated by your solar panels will be used to charge your batteries and any left over electricity generated by your  solar power system is directed onto the power grid. It adds to the overall total of kilowatt hours that can then be used by someone else.

With a battery less system if the grid supplied power goes out due to a storm or other malfunction, the user has no power for lights, furnace, refrigerators, etc, which could be powered by batteries for a limited amount of days.

There is a difference in cost between a battery less grid tie system and one with battery back-up. A battery-less system requires an inverter and a solar array or other renewable power source.

In addition to these two components, a battery grid-tie system requires several batteries, a charge controller for efficient battery recharging, breaker panels, circuit breakers, and enclosures to house the components.  A grid-tie system with battery back-up adds 10%-20% more cost over a stand-alone grid-tie system.

If you are not using batteries, any and all left over electricity generated by your residential solar power system and not used in your home, is directed onto the power grid, where it adds to the overall total of kilowatt hours available, and can then be used by everyone.

These systems will offset your utility usage, with the correct size system it will earn you a credit during the day that you would consume at night. These systems are easy to install and since some do not have batteries for back-up, the lack of batteries in these systems means no battery maintenance or replacements to worry about.

Grid-Tie systems are part of your overall solar system, the number and type of solar panels will determine how much energy you can produce, as will your geographic location. The DC power generated by your panels goes into an inverter.

Inverters

Inverters work by taking the DC power from the source, such as an array of solar panels or wind generators and converts it to AC power so it can be used by your appliances and fed into the grid.

The inverter must also synchronize its frequency with that of the grid (e.g. 60 Hz) using a local oscillator and limit the voltage to no higher than the grid voltage.

Grid-tie disconnects allow you to stop the flow of electricity between your solar power system and your electrical system. This provides for the safe maintenance of electrical and utility systems.  Grid-tie disconnects are also designed to quickly disconnect from the grid if the utility grid goes down.

This is an NEC requirement that ensures that in the event of a blackout, the grid tie inverter will shut down to prevent the energy it produces from harming any line workers who are sent to fix the power grid.

Selling Power Back To Your Utility Company

Ideally you want the utility company to buy back any excess electricity that you produce at the same retail rate that you buy electricity from them at. This is called net metering and is the simplest way to setup a grid-tie solar system.

In such a system you only have one utility kWh meter and it is allowed to spin in either direction depending on if you are buying or selling energy. If your solar power array produced enough electricity, your utility meter would begin to run backwards, and you earn credits on your electric bill.

In a non net metered system, the utility company will require that you install a second kWh meter to record any excess energy that you sell back to them and they will only pay you the wholesale rate.

To find out if your state offers “net metering” or any other incentives for installing a renewable energy system, Click Here.

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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.

Cut Your Power Bill

There are many people today who are interested in knowing about electrical generation at home to reduce their electric bills. With the ever increasing costs of power, now is the best time to stop throwing money out the window, and start saving, by generating your own electrical power.

Whether you want to simply drastically cut your power bills or completely eliminate them, the solution is in using solar and wind power. The main reason more people do not generate their own electrical power is the very high initial start up costs.

Surprisingly Inexpensive

That problem has been solved by building your own electrical generating system. This is actually surprisingly easy to do yourself, using readily available materials that can easily be found everywhere.

There is no longer any need to pay tens of thousands of dollars to convert your home to solar or wind power. Due to modern technological developments you can actually build your own home made electrical generating system for a shockingly low price.

Do It Yourself Manuals

There are guides available that can teach you everything you need to know about electrical generation at home, by using wind or solar power. The top selling manuals have complete step-by-step setup fully illustrated instructions, complimented with easy to follow videos, that make it well within the reach of an even non-skilled homeowner.

Save Money And Help The Environment

In addition to saving money, solar and wind electrical generating systems are completely non polluting which is extremely important in today’s world. With increasing global warming and decreasing air quality, that is being ignored by most governments, it has been left up to the individual to act.

With the low cost of doing your own electrical generation at home, there is no good reason not to do it. Get a good manual and get started today on your own inexpensive, and non polluting power solution for your own home.

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Homemade Solar Power

With dwindling energy resources that contribute heavily to global warming, resulting in changing climates across the globe, more people are looking towards renewable energies for reducing their carbon footprint.

Solar power for your home seems like a great idea, however professional installation of a solar energy system can cost many thousands of dollars. This means that even the most environmentally passionate person cannot do this without the proper financial resources.

This article is aimed at the people who want to do this but do not have these resources. Dramatic changes in technology and information has led many resourceful individuals to building their own solar panels.

How Is It Done?

Solar power for your home may sound like a daunting task, but it is actually much easier than most people realize. If you can you follow simple to understand instructions, then you can build your own solar panels.

There are also solar kits available, and some of them are quite good, it makes it very convenient to get everything in a box, so to speak. Of course they are still quite expensive compared to doing it all yourself.

A basic solar panel is comprised of photovoltaic cells, which are widely available everywhere at a reasonable price. You connect a series of cells together and place the cells into a simple weather proofed aluminum box that has a glass cover.

If you can build a box, you can make a solar panel. The hardest part is doing the wiring, but with a quality set of instructions it is really not that difficult.

When you do it this way you will learn how a solar power system works and exactly how the components are put together. A great benefit of building your own solar panels is that you are learning everything you need to know if you want to expand your system, and you will have the ability to adapt your current system to meet any new design needs.

Homemade Solar Power Manuals

A well designed solar panel should last for well over 20 years. If you are interested in building your own solar panels there are a numerous resources and guides available to help you through the process. What you want to look for in a solar power for your home manual is:

1) It is a top seller. There is a reason it is used more than the other ones available.

2) It is easy to understand. You want a simple step by step plan that is easy to understand.

3) It has video instructions. A picture is worth a thousand words, a video is even better. Most manuals do not have these.

Solar power for your home is a great investment that pays for itself in a short time, and continues to save you money for years by reducing or even eliminating your power bills.

You also have the satisfaction of knowing that you are doing your part to reduce the polluton that is leading to more serious problems like global warming.

Why wait? Making your own power at home while saving money and helping the environment is the wave of the future. Visit The Earth4Energy Home Page.

Video Shots From The Earth4Energy Manual

Save Money And Help The Environment

More and more people today are turning to homemade solar panels as a way to save money, and help the environment. It is not that difficult to do if you get the right instructions on how to build your own solar panels. Modern technology has made home solar power systems available to everyone.

Solar Cell History

Solar cells convert sunlight into electricity and have been around for about 130 years, but only recently have become available and affordable to anyone interested in home solar power.

Semiconductors

Semiconductors are used in solar cells. The use of semiconductors in the 1940’s and 50’s have led to the development of today’s modern conveniences, transistors, microprocessor chips, in fact anything that’s computerized or uses radio waves depends on semiconductors, as do all home solar panels.

The Space Age

In the 1950’s, at the beginning of the space age,  satellites needed a reliable and long term way to be powered. The use of solar energy was the answer. This led to research and development funding from private companies and governments into making solar cells practical, and made today’s homemade solar panels possible.

Photovoltaic Cells

There are several photovoltaic products on the market, including new thin film technology. Photovoltaic cells are devices  that convert light directly into electricity by the photovoltaic effect.

The term solar cell is reserved for photovoltaic devices intended specifically to capture energy from sunlight. You do not have to make the photovoltaic cells, they are readily available at surprisingly low costs.

Build Your Own Solar Panel

When you build a homemade solar panel, you are making a weather proof box with an aluminum frame, covered with glass on the front to allow the sunlight to hit the cells.

The solar cells are wired in a series, the more cells the more power you will gain. The solar cells go in the box and you connect the wiring, and that’s it, you have a solar panel.

Solar Panel Manuals
This is not rocket science but you will need a solar panel instruction manual. The recommended manual not only covers the construction of the panel, but it also has step by step wiring instructions, complimented by video instructions, some thing the others do not have.

If you want to know how to build a solar panel, start with a small investment in a manual to simplify the process. I can not show the video, but I have included some screen shots to give you an idea of what it contains.

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