BuildAfrica.org

From Cell Phone Charging to LED Lights

Aug 31, 2009 Africa, Ghana, Innovators, Power, Technology

In an earlier post, I covered the work of a Ghana inventor named Nana Owusu Acheampong who was using D-Cells and a custom made wooden battery holder to charge cell phones. On a recent visit to Bonsaaso, a small village about 100KM south of Kumasi, the great pleasure of meeting Mr. Acheampong and seeing first hand some of the projects he has been working on.

Cheap Chinese LEDs, which are pervasive in Mali, have not yet reached this part of Ghana so Mr. Acheampong and others have started to make their own LED light arrays powered by wooden box battery holders. Asked how he came about the idea for the battery boxes, Mr. Acheampong explained that observed his radio worked that way so he “took the power out of his radio”.

I’ll let the photos speak for themselves. It was a thrill to meet someone so truly passionate and excited by his own creations. He is exactly the kind of person who with a bit of support, access to better materials and little extra electrical training could help light up a community.

LED light made from MTN advertising and LEDs purchased from Kumasi.

Used CD helps reflect the light from the LEDs.

How Mr. Acheampong lights his room. He no longer purchases kerosene he claims.

Note: Rural Africa still relies heavily on disposable D-Cells for much of its energy. They are popular for their low purchase price, however, they are expensive on a $/AH basis and environmental standpoint. Thus, the idea of creating small businesses around rechargeable D-Cells intrigues me. It seems like an obvious idea but I’ve yet to see it done. If you know of examples of where this is being attempted please let me know.

William Kamkwamba Windmill Maker – Maker Faire Africa 2009

Aug 15, 2009 Africa, Innovation, Innovators, Malawi, Power

One of the real highlights thus far at Maker Faire Africa 2009 has been the presence of William Kamkwamba. William is a remarkable young inventor from rural Malawi, who at the age of 14, built his first windmill out of scrap parts (including his father’s bike) after learning about one in a book.  William’s simple message of not letting your goals be defined by constraints is inspirational and resonated particularly powerful with the other African maker’s in attendance at Maker Faire.

Expect to hear more from William this year as he is about to release a book, The Boy Who Harnessed the Wind, which comes out September 29th. I expect it to be very popular as his is a story that particularly deserves telling.

To learn more about William and find out about his important work please visit: www.williamkamkwamba.com

C-Cell Mobile Phone Charging in Ghana

Jun 24, 2009 Africa, Ghana, Innovation, Mobile, Power, Solar

Nana Owusu Acheampong's C-Cell Phone Charger

Kevin Rehak, an MBA Student at Columbia University that I am working with, recently sent me this photo of an innovative approach to cell phone charging in Ghana.  Using a charging system he made himself, Mr. Acheampong, one of the Abusuapanin Community Leader’s in Bonsaaso village, use’s 4 C dry cell batteries to charge mobile phones.  The four 1.5V batteries in series adds up to 6V which is similar to the 5.5V that most cell phones require (amperage varies). The set of batteries cost 1 Ghana Cedi and he is able to charge four phones before needing to replace the batteries.  This compares to the 1 Cedi cost of charging a phone at the local cell tower.

Obviously, for a number of reasons this solution is not ideal.  The phones charge very quickly (~10 minutes) but are probably receiving too high of a current which damages batteries.  From an environmental standpoint, this method is particularly wasteful.  All this is to highlight both the huge demand for cell phone charging in rural areas in Africa and a general lack of cheap and efficient technologies available for entrepreneurs like Mr. Acheampong.

Tough Stuff Solar Panel

Luckily, a lot of new products are beginning to enter the market that should help change this.  The Tough Stuff Solar Panel a 1W (5.6V, 174mA) highly robust, amorphous panel that is ideal for charging individual cell phones is a particularly exciting example of this.  More important then spec, the Tough Stuff Panel (with cell connectors) comes in at about €10 or less per panel retail.  The retail price will obviously have to be a bit more but if you consider existing charging practices (see above) even a $20 price-point seems very viable.

Also see related post on 12V Cell Phone Charging Practices in Mali

Rethinking the term “Solar Systems”

Jun 15, 2009 ICT4D, Solar, Technology

I had a really interesting discussion at work with my boss Vijay Modi and some colleagues about the real costs of an off-grid “solar” systems.  The perception is often that solar panels make up the bulk of the cost of an off-grid system.  The reality, however, with any time horizon over three years is that the cost of batteries will be the biggest determining factor of cost over time.  It is for this reason, that Mark Hankin’s argues that off-grid system should not be called “solar systems” but rather battery-based systems.

If you consider that most off-grid systems in Africa fail after three years, this term is unfortunately even more appropriate.

Off-Grid Solar Calculator

May 3, 2009 Africa, Power, Resource, Solar

Part of my job over the past couple of years has entailed doing energy sizing for off-grid photo voltaic (PV) solar systems.  To help with this I have relied largely on an excel-based solar calculator that I created.  I thought it might be useful to share.

• Solar Toolkit – excel based solar calculator. Last updated 05.03.09. Please see instructions for proper usage.
• Solar Radiation Chart – useful for estimating peak solar of your location (# hours of day of strong sunlight)
• Solar Radiation Chart 2 – includes optimal PV inclination angles for facing the sun

Please note: this is NOT intended to replace getting a detailed power estimate from a local solar expert who can best take in account the local conditions. This is more intended to help you with estimates when you are looking to bring a project off-grid. Please use at your own risk.

Solar Costing

A common question relating to PV systems is what does it cost?  A technique commonly used is to estimate the cost at $10-per-watt. This includes the cost of the panels, batteries, charge controller and wiring – installed.  A 100W system, for example, would cost you around $1,000.   You can begin to see why we tend to get so nutty about power efficiency! =)

Note: In Africa we’ve found this price to vary widely from $10 to over $15 due to different policies on import taxation, transport costs and varying levels of local competition.  Also, $10-per-watt is for the initial setup of a PV system only.  To consider issues of sustainability, it is important to take in account that batteries will need to be replaced every 2-3 years and the charge controller ever five.  If you wish to factor in replacement costs, to keep the system operational,  $15-per-watt should be used.