LEDs are Safer:

Unlike traditional incandescent Christmas lights, LED lights do not get hot – a big plus if you will be using them on a real tree; but really a big plus for anyone and any use.

LEDs are More Energy Efficient:

LEDs use 90% less electricity than regular Christmas lights, saving you money on your holiday utility bills, and reducing your impact on the environment.

LEDs Last Longer:

LED light lasts up to 100,000 hours. Assuming you use your Christmas lights five hours a day between Thanksgiving and New Year’s, that’s only 200 hours of use each year! How’s that for long-lasting?

LEDs are More Durable:

Since LEDs use light emitting diodes (not incandescence) to produce light, there are no filaments to have burn out; and thus, no bulbs to replace. Just plug in your Christmas lights, and they’re ready for use. Also, since the bulbs are plastic, rather than glass, there’s less chance of breaking lights while you’re stringing them up, and less time spent fussing over how they’re packed up after the holidays. Just toss them in a box, and forget about them until next year.

LEDs Come in a Variety of Styles:

Big bulbs, small bulbs, colored bulbs, white bulbs—LED Christmas lights come in a wide variety of styles – so there’s truly something for everyone. You can even find snowflake-shaped lights, rope lights and net lights.

LEDs are Inexpensive:

Strands of indoor/outdoor lights can be purchased from big-box retailers for as little as $9.99 a strand.

LED Pitfalls:

While LED lights save a lot of energy and money, they may not be for everyone. Take a trip to the store to look at the technology first-hand. Then, decide if LEDs are right for you. Most retailers have displays that allow you to try out the bulbs, and some may even have entire trees or displays decorated with them.

    * Storage: The most common hot water system used in homes. Water is kept constantly heated in the storage tank by electricity, natural gas, oil, or propane. Hot water is drawn out of the top of the tank when a faucet is turned on and cold water flows in the bottom to replace it.

    * Tankless: Also known as demand or instantaneous water heaters. Water is heated instantly by electricity or gas when water flows through it.

    * Solar: Water is circulated from the tank through a solar collector where it is heated by the sun. If the water in the tank is not hot enough, a conventional water heater is used to bring it up to the desired temperature.

Decisions, Decisions

So which type of solar water heater is right for your home? There are several factors to consider including the price of the system and installation, the cost and availability of energy sources, and the energy factor (EF) rating of the water heater.

EF ratings were established by the U.S. Department of Energy to compare the energy efficiency of various products. The EF scale for solar hot water runs from a low of 0.5 for gas storage tank heaters to 2.0 for electric heat pump models. The higher the EF, the more efficient the water heater. The EF number takes into account:

    * Recovery Efficiency: How efficiently the heat is applied to the water.

    * Standby Loss: The percentage of heat loss per hour of the stored water.

* Cycling Loss: The loss of heat as the water circulates through the unit.

An LED is a Light Emitting Diode, and is a semi-conductor device which will glow if you pass a current through it. A semi-conductor is a material which in it's natural state won't conduct electricity well, but if you add tiny quantities of other materials LED will conduct quite well.

Normally each atom in the semi-conductor has 4 electrons and there are none free, but if you add a few atoms with 5 electrons there are some extra electrons which can move easily and carry a current (an N-type semi-conductor). Similarly if you add some atoms with only 3 electrons and then you get some gaps which other electrons can move into (a P-type semi-conductor). The electrons can now move a bit like the tiles in a sliding tile puzzle, but it is easier to think of a positively charged hole moving through the semiconductor.

.A diode is made if you join a lump of P-type semi-conductor to a lump of N-type. If you make the N-type region negative and the P-type positive, electrons and holes will move towards the junction and there are plenty of charge carriers there and a current can flow.

But if you make the N-type region positive and the P-type negative then electrons and holes will be pulled away from the junction leaving the junction with nothing to carry current, so it becomes insulating and a no current can flow. Read More>> 

Tips: LED    led light     led display

When you use solar lighting you are making a contribution to preserving the safety of our environment as well as saving you money. You can feel good that you are helping with an environmental cause, just by saving enough money to significantly lower your electric bill.

Every solar lighting fixture has a highly complex, scientifically designed solar collector panel. The solar lighting is collected and then turned into stored energy. Especially at night, this stored energy can light the outdoors of your home without any additional use of electricity.

Because every solar lighting works alone, there is no need for any kind of transformer or wiring of the lights. Therefore, solar lighting is great for waterside and remote locations. Solar lighting is a high technological, high quality, inexpensive and especially efficient way to light your home—especially outdoors.

Continue reading about related information and more!  

Solar lighting makes use of the most up-to-date technology. Great ways to use your solar lighting are for things like gardens, walkways, and patios.

Solar lighting does, however, require unobstructed exposure to sunlight during the daytime in order to re-charge the batteries required in order to provide solar lighting. But if they do acquire the proper sunlight, a solar lighting device will present you with hours and hours of nighttime light without the use of energy. You can purchase solar lighting devices online, and select from the great merchandise already available. But it is my hunch that even more solar technology is on the way—and that it will happen sooner than later.(solarhome.org)

Tips: solar water heater         solar lighting        solar panel 

It's not hard to see why outdoor solar lighting is so popular. Of course it's great that you don't have to pay for electricity, but the big advantage is the fact that you don't need to install any wiring. Take the light out of the box, install it beside your walkway or in your garden, and that's it.  And since most solar lights have a built-in darkness sensor, you don't even need to think about turning them on and off morning and night.

The technology for outdoor solar lighting is improving rapidly. No more the dimly lit globes that stopped shining in a few hours but solar lights are looking more attractive, shining more brightly, and their run-time is getting longer. To give you a better sense of how these lights work and how to select a good one, here are the basic components:

Solar Panel: The solar panel has a photovoltaic cell inside, which converts sunlight to an electrical current. A solar panel's effectiveness depends on the size and quality of the solar cell and the transparency of the protective cover. The solar cell itself is usually the most expensive part of a solar light. As photovoltaic technology advances, prices are gradually coming down. 

Battery: The solar cells are wired directly to a re-chargeable battery that stores the electricity generated by the cell. A diode located between the cell and the battery ensures that electricity flows only one way -- into the battery. NiMH batteries are often used because they stand up better to the frequent charge and release cycles than standard NiCAD batteries. NiMH batteries also have a significant environmental benefit. They can be disposed of without harm to the environment. The battery is usually the second most costly component of a solar light. For preference do not choose a light with a NiCad battery.

LED: "Light-emitting diodes" are like miniature light bulbs that are installed in-line on an electrical circuit. The light emitted by an LED bulb is a result of electrons moving through a semi-conductor material. Since there's no need for a filament, these bulbs last a very long time and also do not generate heat so the total energy input is converted to light output rather than heat.. The standard runtime of most LEDs is upwards of 100,000 hours, while an incandescent bulb only lasts for about 3,000 hours. LEDs can also be wired in clusters to intensify the light output. 

Sometimes manufacturers of solar lights increase brightness by combining LEDs with a small halogen bulb. But as LED technology improves, most manufacturers are shifting away from halogen in favor of all-LED solutions. The only exception is solar security lights, which still require the extra light intensity provided by halogen bulbs.

Circuitry: This is the most crucial component of a solar light, and the one that most often separates the good solar lights from the bad. Circuit design determines how efficiently the stored electricity is converted into light. High-quality circuitry will give you a longer-lasting, brighter solar light.

Run Time: The type of light bulb plus the quality and integration of the components described above determines how many hours the light will shine. Run times can be as short as an hour or as long as a few days.

Housing: Whether a solar light is strictly functional or highly decorative, its housing needs to be UV-stable and weather tight. Assembly should be minimal. In most cases, the solar panel will be an integral part of the light itself. Sometimes the solar panel is separate, which allows you to mount the light where you need it, and then mount the panel where it will get the best sun exposure.

Solar lights have either a manual on-off switch or a photo resister that turns the light on when the sun sets and off when it gets light again.

Tips : solar water heater   solar lighting   solar panel

LEDs offer numerous benefits due to their mode of operation:

Energy Efficiency

LEDs are highly efficient. In traffic signal lights, a strong market for LEDs, a red traffic signal head that contains 196 LEDs draws 10W versus its incandescent counterpart that draws 150W. Various estimates of potential energy savings range from 82% to 93%. With the red signal operating about 50% of the day, the complete traffic signal unit is estimated to save 35-40%. It is estimated that replacing incandescent lamps in all of America’s some 260,000 traffic signals (red, green and yellow) could reduce energy consumption by nearly 2.5 billion kWh. At the end of 1997, more than 150,000 signals were retrofitted, almost all of them red.

In architectural applications, the greatest penetration of LEDs has been in exit signs, both new signs and retrofits. LED retrofit products, which come in various forms including light bars, panels and screw in LED lamps, typically draw 2-5W per sign, resulting in significant savings versus incandescent lamps with the bonus benefit of much longer life, which in turn reduces maintenance requirements. Some of these products are designed specifically for either on-face or two-face exit signs. Many new LED exit signs are also available, including edge-lit designs. LED products currently make up about 50% of the exit sign market. A study conducted by the Lighting Research Center in 1998 found that about 80% of new exit signs being sold in the U.S. utilize LEDs. Note that most retrofits are restricted to use in stencil-type signs versus panel-type signs.

Long Life

Some LEDs are projected to produce a long service life of about 100,000 hours. For this reason LEDs are ideal for hard-to-reach/maintain fixtures such as exit sign lighting and, combined with its durability, pathway lighting. This service life can be affected by the application and environmental factors, including heat and if being overdriven by the power supply.

Range of Colors

LEDs are available in a range of colors (see above), including white light. White light can also be produced through color mixing of red, blue and green LEDs. In addition, through the innovative combination of various-colored LEDs, dramatic color-changing effects can be produced from a single fixture through dynamic activation of various sets of LEDs. Manufacturers such as Color Kinetics offer fixtures that employ this principle. Color Kinetics offers track, theatrical, underwater, outdoor and other fixtures utilizing variable-intensity LEDs that can provide more than 16.7 million colors, including white light. These fixtures can be individually controlled via a PC, DMX controller or proprietary controller to generate effects including fixed color, color washing, cross fading, random color changing, strobing and variable strobing.

Dr. Nadarajah Narendran of the Lighting Research Center is doing some exciting research on the use of colored LEDs in retail display lighting. Preliminary research suggests that using colored LED background lighting combined with spot lighting on merchandise may improve energy efficiency and reduce maintenance costs while catching the eye of the consumer in a fresh manner.

No UV Emissions/Little Infrared

LEDs produce no UV radiation and little heat, making them ideal for illuminating objects, such as works of art, that are sensitive to UV light.

Durable

LEDs are highly rugged. They feature no filament that can be damaged due to shock and vibrations. They are subject to heat, however, and being overdriven by the power supply.

Small Size/Design Flexibility

A single LED is very small and produces little light overall. However, this weakness is actually its strength. LEDs can be combined in any shape to produce desired lumen packages as the design goals and economics permit. In addition, LEDs can be considered miniature light fixtures; distribution of light can be controlled by the LEDs’ epoxy lens, simplifying the construction of architectural fixtures designed to utilize LEDs. A controller can be connected to an LED fixture to selectively dim individual LEDs, resulting in the dynamic control of distribution, light output and color. Finally, DC power enables the unit to be easily adaptable to different power supplies.

Tips:  LED  LED Light  LED Display