Congratulations Seneca High School Green Club

Congratulations to the Green Club of Seneca High School of Louisville, Kentucky for winning the Louisville Solar Week 2010 Solar Oven Challenge. They obtained a temperature of 175 degrees F (79 C). This accomplishment they earned $100. They also won the kiloWatt Challenge of producing the most power from a dynamo driven by a bicycle. Again they won another $100.

The environmental club team from DuPont Manual High School were runners-up in both events.

Solar Powered Marshmallow Roaster

Solar roaster on top of grill

This link provides the instructions on building a solar marshmallow roaster. Read the whole page and look at the picture of what a large fresnel lens can do to pennies in 3-4 seconds.

Inside of Solar Roaster
Built September 2010 - Louisville, KY

This can be accomplished with the following materials: fresnel lens magnifier (like this one at amazon.com), cardboard box, coat hanger, aluminum foil, glue and tape.

On a partly cloudy day, this roaster got a marshmallow to 160 degrees F. In future tests hopefully it will get hotter.

Update: BE CAREFUL WITH SOLAR COOKERS!This one was left unattended and when checked on it a hole had burnt into the cardboard on the side leaving the aluminum foil exposed.

Producing Solar-Powered Lanterns in Kenya

Video: Making Solar-Powered Lanterns from Scrap Metal


September 16, 2010 | CNN

Story about a man in Kenya who employees people to take scrap metal and form it into pieces to create solar powered lanterns. The white LEDs, solar panel and rechargeable batteries are imported from China. Not quite sure how the lamps save lives or what price they are sold for. A guess would be they replace candles or oil lamps that could start fires. Another question is how long do the batteries last? Is there a plan to replace the batteries? If they could put more people to work manufacturing batteries that would be impressive.

Solar Power Rocks

Doing a Google search on "louisville solar power" a web site called solar power rocks.com was on the first page of results. Nice colorful graphics with some humor thrown in. The September 1, 2010 entry shows a report card entitled "2010 Solar Incentive Summary Grades By State". Kentucky was given an F and Indiana a D.

I dispute the grade for Indiana and think it should be at least a C. The grades listed for Indiana are D, A, C, and A. So that would 1.0 + 4.0 + 2.0 + 4.0 = 11.0 /4 = 2.75 GPA. This value could be argued to be a C+.

Discounted Do It Yourself Solar Power!

Looking at The Courier-Journal's sales circular in Sunday's paper (09/13/2010), they had a page from Harbor Freight Tools. One item listed in particular seemed like a good deal, a 45 Watt Solar Panel Kit (12 volt battery & power inverter not included) for $149.99. It lists the manufacturer as Chicago Electric Power Systems. An earlier post on this blog about a video on YouTube spotlighting this system can be found here.

As of this writing the web site shows the 45 Watt Solar Panel Kit at $199.99 but if you visit their coupon web page: http://www.harborfreight.com/clippermag it has coupon to get it for $149.99.

There are about 50 comments from customers who bought the system so make sure to read them to get an idea about the limitations of the panels and value.

They also have a 5 Watt Solar Battery Charger for about $30: http://www.harborfreight.com/5-watt-solar-battery-charger-41144.html

Solar Cooker

This link leads to a PDF entitled "Investigation of Reflective Materials for the Solar Cooker" by John Harrison of Florida Solar Energy Center (December 24, 2001). It is a 21 page report that reviews materials that can be used for solar cookers.

Interestingly, item #11 talked about in the report is Aluminum foil (heavy duty). The material specifically reviewed is Reynolds Wrap® Aluminum Foil. On page 7 of the report, this foils connection to Louisville, Kentucky is described. U.S. Foil Company was found in Louisville in 1919. The company would be the parent to Reynolds Metals Company. Rolled aluminum foil used as packaging was developed in 1926. The foil used today is of 8111 alloy aluminum (98.5% content) with silicon and iron added for strength.

Aluminum foil is the most popular material used for solar cookers due to its low cost and availability. It does have issues in being fragile being so thin and can develop a aluminum oxide film when exposed to moisture. Holes can form in the foil as well when exposed to acidic or salted foods.

Learn more about solar cookers and their research at this web site.

Do It Yourself Solar

This video on YouTube has a homeowner describing how he installed a Harbor Freight Solar System. In the video he says the system has been used for more than a year to power two lights in the house. Looking at the Harbor Freight web site they have a solar panel kit for $200 that looks similar to what he is using. A person still needs to get a battery and power inverter.

If I got one of these I think I would try using a DC-DC (direct current) converter to power the computer router/Internet/battery chargers from the DC battery since all these devices use DC instead of AC (alternating current). Also try to find LED lights that use DC instead of converting AC.