Solar energy:
Solar technologies use the sun's energy to provide heat, light, hot water, electricity, and even cooling, for homes, businesses, and industry. Despite sunlight's significant potential for supplying energy, solar power provides less than 1% of U.S. energy needs. This percentage is expected to increase with the development of new and more efficient solar technologies.
Different types of solar collectors are used to meet different energy needs. Passive solar building designs capture the sun's heat to provide space heating and light. Photovoltaic cells convert sunlight directly to electricity. Concentrating solar power systems focus sunlight with mirrors to create a high-intensity heat source, which then produces steam or mechanical power to run a generator that creates electricity. Flat-plate collectors absorb the sun's heat directly into water or other fluids to provide hot water or space heating. And solar process heating and cooling systems use specialized solar collectors and chemical processes to meet large-scale hot water and heating and cooling needs.
Solar technologies produce few negative environmental impacts during collector operation. However, there are environmental concerns associated with the production of collectors and storage devices. In addition, cost is a great drawback to solar power. Although sunlight is free, solar cells and the equipment needed to convert their direct-current output to alternating current for use in a house is expensive. Electricity generated by solar cells is still more than twice as expensive as electricity from fossil fuels. Part of the problem with cost is that solar cells can only operate during daylight hours. In contrast, a coal or natural gas plant can run around the clock, which means the cost for building the plant can be spread over many more hours of use.
Around the United States, available sunlight varies considerably as a result of differences in cloud cover and latitude, and also varies with the seasons. In the summer, longer daylight hours and a higher sun angle provide more solar power, compared to the winter when the sun is up for fewer hours and at a lower position in the sky. These variations must be taken into consideration when planning solar collection facilities.
- Related Articles
- Related Q&A
- A Jewish Graveyard and a Battlefield
- Incidence of Gastrointestinal Helminthes in Captive Elephants in Wildlife Reserves of Nepal
- Third Ruck From the Son
- Islam 101- Who is Muhammad?
- Has the Palestine Liberation Organisation Lost the Plot - or Missed the Boat?
- The Holy Line of Prophet Muhammad (saas): Sayyids
- Alkab
- How to Stay in Touch With Your Pashto Language Roots




Middle School Science Projects for Winning Middle Schoolers
By: Kayla Fay | 13/11/2009Middle school science projects aren't assigned so that every child can win the science fair, but it's the rare student that wouldn't like to be a winner. Here are four ways to improve your chances of grabbing one of those first place ribbons.
What Does Your Government Want Your Child to Learn About Science
By: Morton Barish | 12/11/2009It would be important to know what the Federal Government thinks about what your child should learn about science.
How to Crack the DAT Exam in 24 Hours
By: Dr. Wayne Huang | 12/11/2009Rapid Learning System uses the three components above with rich-media with focus on concept understanding and problem solving. Any DAT course has 24x rich-media videos, 24x problem drills and 24x cheat sheets.
Science Projects Made Easy
By: Leo J. Vidal, JD, MA, CPA | 12/11/2009Science Fair projects are a breeze with this new online educational resource for parents, teachers and students. Now in one place you will find every science project kit or book on science experiments, in the internet's largest repository of science project materials and resources.
Cosmic Latte - The Color of the Universe
By: Andy Thomas | 12/11/2009Pondering the average color of the universe.
Concrete on moon, a flight of fancy!
By: Concrete Techgroup | 12/11/2009Recent discovery of water on the surface of moon has renewed the discussions on feasibility of human habitations on moon. If humans are to live there, can Concrete be far behind? Eminent Engineer Shashank Vaidya in his article under Concrete Thought Leader Series (published by http://www.ConcreteBasics.org ) takes you through the interesting aspects that will have to be catered to for making concreting on moon a reality.
Looking For Microscopes For Sale?
By: Trevor Coleman | 12/11/2009Finding microscopes for sale will probably take a large amount of time and energy on your part. All that hard effort is immediately rewarded when you see your kids exploring the world around them. Microscopes are a superb way for them to do that, so how does one get a good one and at a good price? There are 2 ways you can go about your search. You could get in your car, drive all over town and compare store after store. Once you do that you then have to review your options an...
What Jobs Can I Get With a Bachelors of Science Degree?
By: Madeline Binder | 11/11/2009Starting a career in science doesn't have to wait until you have a PhD. There are many jobs in science that only require a bachelors of science degree.
Climate of Pakistan
By: Hamza Naeem | 06/12/2007 | Childhood EducationPakistan climate and controling factors of climate in Pakistan.
Solar Energy
By: Hamza Naeem | 09/11/2007 | ScienceThe solar energy in America. Solar energy is reliable but in Amreica its not reliable because there is less heat in America
Geothermal Energy
By: Hamza Naeem | 09/11/2007 | ScienceGeothermal energy in America is reliable but it needs too much of space and it can also destroy wildlife
Emergency in Pakistan
By: Hamza Naeem | 07/11/2007 | PoliticsAllah please save our country and give our leaders politeness so that we can live happily
Lack of Energy in Earth
By: Hamza Naeem | 07/11/2007 | ScienceWe should save energy so that there should not be lack of energy in future.
Solar Energy in America
By: Hamza Naeem | 07/11/2007 | ScienceThe use of solar energy in America. Its not reliable to use it because there is less heat in America
Wind Energy in America
By: Hamza Naeem | 07/11/2007 | ScienceI think the best energy in America is wind energy. And it should be used in America.