Scheffler Reflector in Afghanistan, Solar Tandur

Scheffler-Reflector in Afghanistan

Manufacturing of the first Scheffler Reflector in Afghanistan was started in August 2005 in the Bedmoschk Solar Centre.
Scheffler Reflectors can be used for solar cooking, solar baking, solar food processing and as well for production of steam for applications of process heat or for the requirements of hospitals (laundry , autoclaves, cooking)
The first application used in the solar village of Bedmoschk is a Solar Tandur.
For this part of the project Solare Brücke e.V. is our technical partner.
Technical details about Scheffler Reflectors can be found at www.Solare-Bruecke.org.
Through the trainings facilitated by our association the afghan company Afghan Renewable Energy Center LTD (ARE) in Kabul is now manufacturing 10m² Scheffler Reflectors for institutions as well as 2,7m² Scheffler Reflektoren for families.



December 2006: Since September the first 2,7m² Scheffler Reflector installed in Afghanistan cooks for a family in the outskirts of Kabul.

In Dezember 05 the first 10m² Reflector for baking and cooking was installed in Bedmoschk. At the same time we started training staff from Afghan Renewable Energy Center LTD (ARE) in Kabul . In April 06 the first 10m² Reflector was installed for demonstrational purpose at ARE. Production of further reflectors started in small series.


	In April 2006 training for the construction of 2,7m² Scheffler - Reflectors (for families) started at ARE LTD

test of the tracking device (mechnaical clockwork)

Manufacturing of the first Scheffler-Reflector:

steel is cut and bent, bending the metal bars requires great accuracy

the shape of the reflector frame is checked

In december 05 the first reflector was installed. It can be used for baking "Nan" and "Chapati" als well as for cooking.

A traditional tandur is installed.
The tandur weighs abuot 70kg and was built locally from clay.

The tandur is preheated.
Concentrated light falls through a glass lid into the oven. The secundary reflector (here from aluminum sheet) on top of the glass lid makes sure that all light is refelcted into the oven.

dough is prepared

baked Chapatis

Tasty!

A 30l pot is used for cooking and frying.

Developing the Solar-Tandur

Whilst the manufacturing of the first reflectors in Bedmoschk, steps for developing the Solar Tandur have been taken in Ailsingen, Germany at the center of Solare Brücke e.V.

A traditional Tandur is a big clay vessel integrated into the ground:

as long as the fire is going the Tandur is used for cooking

once the fire has burnt down the flat breads are smacked against the hot clay walls of the vessel

Solar Tandur:

to develop a model that is similar to the traditional one in function and form we did the following experiments:

Assembly of the Solar Tandur


			heating up
	Insolation of 14cm rockwool


The clay walls have between 450 and 350 degree Celsius when the bread is smacked against them.
		A glass lid prevents heat losses from convection.

the result

Within the temperatur range of 450°C to 300°C we can bake about 6,5 kg of bread in one hour 50 minutes. The Tandur was preheated for 2.5 hours. The bread was then baked with the stored heat.

We are also testing a baking oven Christoph Müller devoloped in Argentina. We need to find out if it can be adapted to baking flat breads.


	The oven has a baking chamber of 60x60 cm and is heated by a air heat exchanger located underneath the baking chamber. A heat storage from gravel shall provide uniform baking temperatures, it is located under the baking chamber, too. In the background you see the 8m² Scheffler Reflektor used to heat the oven.


at 300°C tasty bread was baked. 250g of bread were ready in 8 minutes. To reach baking temperature the oven was preheated for 2 hours. For further tests we don´t have enough sunshine at the moment .

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