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….

Related articles by Zemanta

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

Image via Wikipedia

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.

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..

Related articles:

• Dow Chemical Rolling Our Solar Shingles Next Year
• Dow sees big market for solar house shingles
• Thin Film Solar Cells Simplified

What Is An Energy Audit

Do you know how your home is using (or losing) energy? Every single home loses energy, but with the power of a simple energy audit, you can save energy by limiting your home’s energy loss.

An energy audit, typically done by a trained energy professional, looks at your home and how it uses and loses heat to electrical usage and waste. It involves walking through your home, and carefully looking for energy problems, some of which even can’t be seen!

Do It Yourself Energy Audit

One of the best and easiest things to do is to switch to energy saving lights, but there is much more that you can do. Before you spend another dime on the latest energy gadget think about this, you can find out how your home uses energy in just a couple of  hours by doing your own home energy audit.

A do it yourself energy audit is the single best way to save energy because it shows you exactly how your home uses energy. When you add the numbers up, you’ll understand how your home uses energy, and once you understand how your home uses energy, you can effectively target and reduce your energy usage.

It is a proven and effective way to lower energy bills and save energy in any house.

And the best part is, if you do it yourself, it is free. You don’t have to pay a professional a couple hundred dollars to come in and give you their opinion, or ‘recommend’ expensive repairs. When done correctly, an energy audit is 100% effective. It is an absolutely indispensable tool for saving energy.

Easy To Do

Energy audits are simple. There isn’t much to them, so there isn’t a lot that can go wrong! Typically, when a process involves many steps, there is greater risk for error. Energy audits don’t have a lot of complicated steps, so chances are the results you get are accurate.and its repeatable.

This means that every season, every year, you can repeat the process and track or monitor your energy usage and correct any new problems.

Once an energy audit is done, the results are unmistakably clear. You will see what uses the most energy, the potential areas for saving, and even a cost/benefits analysis of major home repairs like adding insulation or replacing windows versus savings.

Every home is different and I’m not just talking structurally. Every single homeowner is different too, in both their habits and energy usage. So, everyone uses energy differently and every home uses energy differently.

The techniques of an energy audit are generic and can be adapted for any home, but because an energy audit tracks and inspects a single home’s energy usage, the results are very specific and custom tailored to your own home.

Savings

Once you know where the problems are, you can put forth an energy savings plan that will work for your home because it attacks the causes of your energy loses.

For example should you replace your windows because it will save energy?  Some homes might need new windows or maybe not, an energy audit will tell you what you need to do, and how to save energy in other parts of your home.

The amount you can save varies by home and location. By doing an energy audit yourself, you are already saving $100 to $200 because you’re not paying someone to conduct the audit. A lot of people get results of 15-40% savings in energy costs by actually finding and reducing energy usage.

The do it yourself audit kit was put together by a former audit professional Dave Andersen. It is a collection of pdf guides and excel workbooks that estimate and predict energy usage and calculate energy loss, it is easy  to use, yet it gives you a wealth information about your homes energy.

To learn more about this diy energy audit Click Here

Electrical Vampires

Your computer is using energy right now, now that is not a surprise as you are using it, what comes as a surprise to most people is the fact that the average computers idle time represents from 70% to 90% of its total annual energy use.

Something that many people don’t even know about is standby power, also called phantom power.  This means that even when not in use, power is being sucked away or drained (electrical vampires) from your electrical devices.

Drawing Power When Not In Use

Many of us have adopted the habit of simply leaving the computer running for hours or even days when we are not even using it

Your computer, monitor, printer, sound system, external drives, scanners and other peripheral devices sit quietly in the background consuming power, even if we do not use the computer for days.  For instance computers can draw 7-8 watts or more when not in use. This adds up over many hours.

Wasted Power

An individual product draws relatively little standby power, but a typical American home has around 30 products constantly drawing power and this can amount up to 10% of your electricity use, and it is completely wasted power.

Think about it, a PC, a laptop, TV’s, Stereos, two or three cell phone chargers and a lot more all constantly drawing power, even though they are not being used.

So what are your options? Unplug the device when it is not being used, plug it in and use it, and then unplug it again? Thats not going to happen. Hang garlic on everything to ward off electrical vampires? Sounds pretty good, but I will pass.

Smart Strips

New solutions to this problem have been showing up in the market place called smart strips, they look like a regular surge protector, but have the ability to eliminate most of the power drain

There is a control outlet for your computer, and automatically switched outlets for your printer, monitor, etc. When you turn your PC on, the smart strip turns on the switched outlets and powers your peripherals, when you turn the PC off,  it cuts power to the switched outlets and all the peripherals.

A simple and easy solution to this hidden power drain,  the smart strips can also be used to save energy on televisions and home entertainment systems as well.

Save Money And Help The Environment

Saving 5-10% on your bill may not sound like much, but it compounds over the months and years, and it can amount to a substantial figure.

Will it really make a difference and help the environment? The answer is yes, even modest energy savings multiplied by many people can make a big difference, and it all begins with you making changes.

To stop wasting energy and to learn more about smart strips, go to Amazon.com, they have several of these at prices that will quickly pay for themselves, while conserving energy and helping the environment.

Related articles by Zemanta

• Are we wasting our ‘Vampire Energy’? (techburgh.com)
• Ghostbusters: Exorcizing the phantom load (energyrefuge.com)

Image via Wikipedia

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.

Image via Wikipedia

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.

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.

Earth4Energy