Tuesday, June 14, 2011

Solar exterior wall lights

Solar exterior wall lights are manufactured in utility appearance as well as in a decorative style. Due to their unlimited benefits, home and business owners install them outside their properties. They are designed in a wide range of different creative shapes, materials and finishes. They are very easily to install by any person who is familiar with the use of a screwdriver. There is no need to call a professional electrician to install them. In conclusion, we can that the use of solar exterior wall lights is a great way to save money and electricity which will cause to save the planet.

Solar lights

Solar lights are widely used in different applications. They are very reliable due to their healthy effect, low consumption power and cheap cost. One of the most beneficial applications of solar lights is solar exterior wall lights. These lights are used on the outside walls of your home. They are fixed in the form of bulb at the outside corner of the walls. They provide a bright and beautiful view to the outer structure of your home at night. Basically solar exterior wall lights have many options in the bulb configuration which you can use. But your source of light is single then dual bulbs are required.

In solar exterior wall lights, the light source is LED bulbs because their brightness if so clear and same as any type of fluorescent bulbs. These lights have a long life and also they don’t create heat. That’s why you can easily them in different areas without any worry, damage and fear. Actually the majority of these lights have a range of sensors. It means that they can be fixed with onboard timers, different sensors as well as motion sensors too. These qualities become solar exterior wall lights the best solution for safety and security in the home as well as business environments.

Amorphous Silicon Solar Cells

The efficiency of amorphous solar cells is typically between 6 and 8%. The Lifetime of amorphous cells is shorter than the lifetime of crystalline cells. Amorphous cells have current density of up to 15 mA/cm2, and the voltage of the cell without connected load of 0.8 V, which is more compared to crystalline cells. Their spectral response reaches maximum at the wavelengths of blue light therefore, the ideal light source for amorphous solar cells is fluorescent lamp.

Crystalline Silicon Solar Cells

Among all kinds of solar cells we describe silicon solar cells only, for they are the most widely used. Their efficiency is limited due to several factors. The energy of photons decreases at higher wavelengths. The highest wavelength when the energy of photon is still big enough to produce free electrons is 1.15 μm (valid for silicon only). Radiation with higher wavelength causes only heating up of solar cell and does not produce any electrical current. Each photon can cause only production of one electron-hole pair. So even at lower wavelengths many photons do not produce any electron-hole pairs, yet they effect on increasing solar cell temperature. The highest efficiency of silicon solar cell is around 23 %, by some other semi-conductor materials up to 30 %, which is dependent on wavelength and semiconductor material. Self loses are caused by metal contacts on the upper side of a solar cell, solar cell resistance and due to solar radiation reflectance on the upper side (glass) of a solar cell. Crystalline solar cells are usually wafers, about 0.3 mm thick, sawn from Si ingot with diameter of 10 to 15 cm. They generate approximately 35 mA of current per cm2 area (together up to 2 A/cell) at voltage of 550 mV at full illumination. Lab solar cells have the efficiency of up to 20 %, and classically produced solar cells up to 15 %.

Solar Cells

Solar cells are in fact large area semiconductor diodes. Due to photo voltaic effect energy of light (energy of photons) converts into electrical current. At p-n junction, an electric field is built up which leads to the separation of the charge carriers (electrons and holes). At incidence of photon stream onto semiconductor material the electrons are released, if the energy of photons is sufficient. Contact to a solar cell is realized due to metal contacts. If the circuit is closed, meaning an electrical load is connected, then direct current flows. The energy of photons comes in "packages" which are called quants. The energy of each quantum depends on the wavelength of the visible light or electromagnetic waves. The electrons are released, however, the electric current flows only if the energy of each quantum is greater than WL - WV (boundaries of valence and conductive bands).

Saturday, April 16, 2011

GreenPower options

Origin GreenPower is generated predominately from solar, wind and biomass sources. All of our GreenPower products meet the stringent accreditation rules of the Government's GreenPower program.
How does it work?

When you purchase one of our Government accredited GreenPower products, we'll have the chosen percentage of your electricity consumption matched into the electricity grid with electricity from GreenPower accredited renewable sources such as wind, solar, hydro and biomass.

Why solar electricity?

With an Origin solar electricity system, you'll:
Save money on your energy bills by generating your own clean electricity
Find it easy – your system comes fully installed and we'll organise everything from your paperwork to connection to the grid
Get a grid-connected solar energy system that best meets your needs
Enjoy competitive prices
Be helped by our team of dedicated solar energy specialists
Relax, knowing your solar panels come with a 25 year power output warranty
Enjoy peace of mind that your system will be installed by a BCSE grid-connect accredited installer, who will personally sign off on the installation report at the time of commissioning
Rest assured, knowing you're dealing with Australia's number one green energy provider.
Be rewarded with feed-in tariffs. If your solar system generates more power than you need, you have the potential to be reimbursed for any electricity your system feeds back into the grid, thanks to State Government feed-in tariffs (FITs). A feed-in tariff is a buy back rate paid on a net basis for any excess power your system produces that you don't first use in your home. Feed-in tariffs are designed to encourage more Australians to generate their own electricity and vary by state.

Solar Energy and Personal Empowerment

 Harnessing the Sun: How Solar Energy Empowers Individuals and Communities Solar energy isn't just about powering homes; it's about ...