Tuesday, December 2, 2008

Basic Things to Consider Before Buying a Solar Electric System

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Installing a solar power system requires very careful initial planning. First of all, you need to know exactly how much electricity your home uses each month. You may look up in your old electricity bills but also you should think about how your electricity needs will change over the next 10 years.

Solar photovoltaic panels can be installed on the roof, along a wall of the property or as standalone systems. If you are planning to install them on your roof, you need to make sure that the roof is strong enough to hold a solar panel because some of these panels can be quite heavy. A roof inspection (and any necessary repair) is recommended prior to a PV installation. Another thing you need to know is that the more sunlight modules collect, the more electricity they produce, thus the more energy your home will receive. Make sure that the roof (or wherever you intend to install your solar panels) is clear of any obstacles, such as trees or buildings, especially during peak production hours between 10am and 2pm.

Ideally, a solar system will go on a south/southwest-facing roof, although east and west facing roofs are good candidates, as well.

You should decide whether your system will be grid-connected, off-grid or hybrid. With a solar PV system connected to an electric distribution system (grid-connected) you can receive back-up power from it when your system doesn’t produce enough energy for your needs. When your solar PV system produces excess power, that electricity can be send back into the grid, and your local utility is required to buy it from you.

Picture: apps1.eere.energy.gov

A grid-connected solar power system is easily integrated into the existing electrical infrastructure of a house and the system can provide decades of reliable and environmental friendly electricity production.

A stand-alone (off-grid) solar PV system is independent of an electricity distribution grid operated by a utility. The electricity is provided by solar power alone and stored in a battery for later use. Such systems typically make sense in remote locations.

The average solar PV panel last approximately 30 years and many manufacturer warranties last for up to 20-25 years. Solar PV panels are designed and installed to be low-maintenance. However, it is very important to have your solar panels cleaned regularly because they benefit from being hosed off with water twice a year, especially after long periods without rain. Dust or dirt may cause a 10-15% reduction in their efficiency.

Before buying and installing the panels it is also essential to make sure that you understand the installation regulations in your local area. In most cases it is wise to check with the local authority before installing your solar electric system.



Thursday, November 27, 2008

Lemonade Award

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I was nominated with an award - the Lemonade Award and this is my first award as a blogger (well, this is also my first blog). So, I would like to thank Eco Mama, Its all about our home, the Earth! and Goal For The Green for awarding me with it, and assure you that I really appreciate this acknowledgement! I think that making lemonade out of lemons can be an interesting endeavor, and besides, I like both lemons and lemonade :)

The Lemonade Award is passed to bloggers for showing great Attitude and/or Gratitude and now it's my turn to pass it to ten other blogs.

And here are my nominations :

SolReka
Environmental Chaos
Passionate Green
Chasing The Wind
Green not Mean
Eco-Blogical
Bulgarian Slivatree
Newton's Ocean
Life on a Southern Farm
Teddy Tour

The rules of this award for recipients:

1. Put the logo on your blog or post.

2. Nominate at least 10 blogs which show great Attitude and/or Gratitude!

3. Be sure to link to your nominees within your post

4. Let them know that they have received this award by commenting on their blog.

5. Share the love and link to this post and to the person from whom you received your award.


Sunday, November 16, 2008

Solar Energy and Solar Power

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Solar energy and solar power are two terms that are often used interchangeably but actually they are not the same thing. They both mean to receive and use solar rays, but more specifically solar power refers to electricity generated from the sun's light.

Solar PV PanelSolar energy is a more generic term and it describes all the uses of the light and heat from the sun. That includes solar power generation, but also solar thermal for water heating, space heating and cooling, and heat for industrial processes. Solar energy includes also passive solar energy that uses building orientation, design and materials to heat and cool buildings. 

Solar power is generated directly using photovoltaic (PV) technology. Solar PV panels (made from a semiconductor material) harness sunlight to create electricity to run appliances and lighting in your home. The electricity created by the solar system is direct current (DC), and the electricity we use in our homes is alternating currents (AC). Thus solar systems need an inverter which changes the DC current into useable AC current.

There are also concentrating solar power systems. They concentrate the sunlight using mirrors or lenses onto a receiver to produce heat. Then the heat can be used to generate electricity through steam turbines.

Solar energy is clean, environment-friendly, and most abundant renewable energy source we can use. In my next few posts, I will write about producing your own solar electricity by installing solar PV panels on the rooftop of your house, and what basic information householders need to know at the beginning.


Tuesday, November 11, 2008

Solar Heating Panels on the White House Roof

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Still under the impression of the USA 2008 Presidential vote (although I am not an American) I found this information interesting to be published now.

Did you know that way back in 1979 (during the second US oil crisis) the American President Jimmy Carter installed solar heating panels on the roof of the White House West Wing? I personally didn't know that curious fact! And it seems that the Nobel Prize winning President Carter was quite a visionary.


In July 1979, President Carter outlined his plan for achieving energy independence and improving energy efficiency in his "Crisis of Confidence" speech. In an effort to set an example for the nation, he installed solar panels on the White House roof. They were more as a symbol of a new strategy to reduce America’s dependence of foreign sources of energy and a move designed to support Carter’s solar institute, which he had “created to spearhead solar innovation.”

Carter called for 20 percent of American energy to come from solar power by the year 2000. He even had very generous tax reductions implemented for people who installed solar panels at home.

The solar-energy system that President Carter installed consisted of 34 solar collectors which were used to heat water for the staff eating area and some other areas of the White House.

At the time, President Carter warned "a generation from now, this solar heater can either be a curiosity, a museum piece, an example of a road not taken, or it can be a small part of one of the greatest and most exciting adventures ever undertaken by the American people; harnessing the power of the Sun to enrich our lives as we move away from our crippling dependence on foreign oil." (It turns out Carter's warning was at least partially correct: One of his solar panels is now museum piece.)

In 1986, President Reagan had the solar panels removed during a roof in repair and put them into a federal storage facility. Actually, the solar panels were supposed to be reinstalled but they never were.

In 1991, the environmentally-minded Unity College of Maine, found the panels in a government warehouse in Franconia, Va., bought them for peanuts and installed them to use for the generation of hot water in the student dining hall.

By 2004, the solar panels had worn out. Unity College kept one of the panels for “historical significance,” donated another panel to the Smithsonian Institute and offered the rest for sale.

Even a documentary film has been made about the solar panels, using them as a backdrop to explore American oil dependency and the political lack of will to pursue alternative energy. Swiss directors Christina Hemaner and Roman Keller follow the route of the panels in the hour-long film "A Road Not Taken."

In 2003, the National Park Service, which manages the White House complex, installed a nine kilowatt solar electric or photovoltaic panels, on the roof of the main building used for White House grounds maintenance. Solar thermal systems were also installed to heat water: one for landscape maintenance personnel, the other for the presidential pool and spa.


Sunday, November 2, 2008

Cellular Base Stations Powered by the Sun

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It seems that the mobile industry is another technology field where solar power soon can play an important role in reducing costs and ensuring a reliable power supply.

In a new study ABI Research analysts predict that the future mobile phone base stations will be sun powered. They say that over 335,000 base stations worldwide will be using solar power by the end of 2013, with around 40,000 of those being completely autonomous and off-grid. The research firm explained that improvements in photovoltaic cells have meant that solar energy is now a viable option for supplying power to charging stations.

"The market for autonomous solar powered cell sites looks set to grow from extremely modest levels today to over 40,000 renewable energy sites by the end of 2013. A further 295,000 base stations are expected to supplement on-grid power usage with solar," said Stuart Carlaw, vice-president of ABI Research.

Still, the majority of these cellular base stations will use diesel or mains electricity to supplement their solar panels, especially in areas where population density and less solar energy require it.

Probably the developing countries will be the biggest winners as remote communities will receive phone coverage and Internet connections for the first time. According to some UN figures half of the world is still not able to make a phone call.

Other alternatives to normal electricity for base stations being considered are wind power, fuel cells and even compressed air.

Source: Market Watch