Posts Tagged ‘Institute of Electrical and Electronics Engineers’

18 February

The Challenge of Designing a Solar Cookstove That Works at Night


Dear Readers,

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If you are in favor of renewable,  clean, or solar energy, please sign this petition for FIT/CLEAN Program, accessible at Thank you very much.

Dear Friends and Readers,

Do you remember our January posts (Jan. 5, 6, 7, 9, 2012) regarding solar cookers ?  Take a look/read of them to refresh your memory.  Then, I will discuss a new challenge with you.  As some of you may have tried and  found out, solar cookers only work for a few hours in the middle of a sunny day, but not at night or in the mornings when people actually want to cook.  If we can use solar cookers any time of the day and night, it could replace open fires, solve dire deforestation, and indoor air pollution problems in developing countries.  So, last year, the Climate Healers, an international development technology organization, issued a design challenge after their traditional solar cookers failed to catch on in mountain villages in Rajasthan, India.  The Climate Healers is designing a new cooker that stores the solar energy by day to release it at night.  Students at the University of Iowa, working with Climate Healers, surveyed the women (who would use such a cooker) and found that they were enthusiastic about a new design that will enable them to use solar cooking during nights.

The starting point is a modified Blazing Tube solar cooker that serves as a baseline,

but it needs improvement. So, the Climate Healers has turned to the E4C (Engineering for Change) for help.  The baseline design places a three-gallon glass cylinder in the crook of a compound parabolic reflector-basically a tube on the bottom of a half pipe.  The tube filled with one gallon of oil and an air bubble, warms throughout the day and releases heat at night or the next morning through a heat pipe that the chef controls.  Climate Healers replaced the oil and air with three gallons of table salt.  The salt heated to 626F (330C) at the center of the tube, enough to yield 1KW hour of energy, enough to cook flat bread and lentils for about an hour.


The head of Climate Healers, Sailesh Rao, feels more needs to be done before reaching the final design because of the requirement for transporting large, fragile tubes to remote regions and the need to store adequate energy without leaks all need to be met.  So these three aspect need to be considered: 1. Energy capture 2. Energy storage 3. Energy delivery.

Just think that these designs have the potential to contribute to better health and healthier forests in India and many parts of the world.  Since early 2011, many teams of people have accepted the challenge of making a solar cookstove that works at night.  By Dec. 25, 2011, ten designs meeting this challenge had surfaced.  I would like to invite you to visit these ten designs of solar cookstove that works at night . These ten designs are: iHawk Cooker, Heat delivery system, PETE induction cookstove, CARES stove, Scheffler cooker, Solar box cooker, Parabolic cooker with steam, Box cooker with steam, Molten-salt solar cooker, Solar cooker with oil.

My hat off to Climate Healers and Engineering for Change (E4C) !  Again, we see the importance of the cooperative effort in solving our world’s problems, meeting our world’s challenges.


Engineering for Change (E4C) is an online platform and international community of engineers, scientists, non-governmental organizations, local community advocates and other innovators working to solve global development problems. The organization’s founders are the American Society of Mechanical Engineers, the Institute of Electrical and Electronics Engineers, and Engineers Without Borders USA.


~have a bright and sunny day~

Gathered, written, and posted by sunisthefuture-Susan Sun Nunamaker

Any comments and suggestions are welcomed at

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2 April

What Is Solar Cell (5)


If you are in favor of renewable/CLEAN energy, please sign the petition page showing support for FIT/CLEAN Program at Thank you.

Dear readers/friends, I hope you will stay with me for 3 more posts (up to What Is Solar Cell (7)) before we move on to another topic in solar energy. Thank you for your patience.

In the previous post, you have seen that Boron and Phosphorous may be used to as dopping material to be added to Silicon in the process of making semiconductor material for solar cell. But there are also other alternatives.  As a matter of fact, instead of silicon, gallium arsenide (GaAs) is another possibility.  GaAs based multijunction devices are the most efficient solar cells to date, reaching 42.3% by the triple junction metamorphic cell.  High-efficiency multijunction cells were originally developed for applications such as satellites and space exploration.  Triple junction GaAs solar cells were also being used as the power source of the Dutch four-time World Solar Challenge winners Nuna in 2003, 2005, and 2007.

Scientists and engineers are constantly looking for alternatives that would help to increase efficiency and decrease cost.  Most commercially available solar cells are capable of producing electricity for at least 20 years without significant decrease in efficiency.  Typical warranty given by panel manufacturers is for a period of 25-30 years, without having output falling below a specified percentage of the rated capacity. So, there are products and technologies that need to be tested and validated.  In U.S., NREL (National Renewable Energy Laboratory), located in Golden, Colorado, established in 1974 and began its operation in 1977 as the Solar Energy Research Institute, tests and validates solar technologies.

Keep in mind that there are three reliable certifications of solar equipment: UL, IEEE, and IEC.

  1. UL: Underwriters Laboratories Inc. (UL) is an independent product safety certification organization established in 1894 and has its headquarters in Northbrook, IL.
  2. IEEE: Institute of Electrical and Electronics Engineers or IEEE (read I-triple E) is a non-profit professional association dedicated to advancing technological innovation related to electricity. (45% of its members are located outside of US).
  3. IEC: International Electrotechnical Commission is a non-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic, and related technologies.

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Stay tuned at the same bat channel…more will be in store for you…

Please feel free to leave comments or questions.

Posted by sunisthefuture-Susan Sun Nunamaker,
Any comments and suggestions are welcomed at

Please also get into the habit of checking at these sites below for more on solar energy topics:

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