SOLAR KITCHEN
One of the Garden of Wonders' first projects is a kitchen based on solar energy. With sun shining on over 320 days in Zanzibar, it is the ideal location for solar cookers. Thus, a concrete half-shell and tile mirror form a permanently heating hotplate for water, rice and beans. A special feature and cornerstone of the garden of wonders is the solar oven. This, only heated by the sun, serves the pizza production for the "SunschinePizzaria".
But not only heat, but also cold can be produced with solar energy. But later when it becomes concrete...
a sketch of the solar pizza oven
On the islands of Zanzibar, as in most parts of Africa, wood is used as the primary energy for daily cooking. Thus, the constantly barren bush landscape is thinning steadily. In this way, the nature is prevented from recovering. This as the most important consideration, as well as your health risks of cooking with open wood fire brought forth the idea of the "solar pizza oven".
So much sun, so much heat; - that must be enough for a stone oven.
A stone oven that stores the heat in the evening, as the dinner for locals and visitors is prepared after sunset. This was the framework.
the plan
Initially, the thoughts revolved around a well-insulated stove in which the energy with the help of collectors, the energy is directed through fiber optic cable in the oven. The tracking of the collectors, simply to complex and therefore expensive.
In order to keep it simple and robust, the now favored variant has emerged. Insulated floor and insulated side walls with insulating mats and masonry. In the center, a semi-circular structure of massive rock (such as granite), which were painted from the outside with heat-resistant black color. As a roof, two insulated glass plates are installed one above the other with a small gap.
One glass plate will probably show the desired effect, but we will not know, until it's built.
In addition, at least one collector (e.g., satellite dish) will be installed to increase the radiation intensity to the necessary level.
basement
Construction of the solar oven began in July 2019. The choice of location changed from day to day. When it came to a decision, a completely new kitchen house was planned. And the kitchen house was renamed Salon.
It is exciting whether the location was so good. First of all, a basis for the stove had to be created. The coral stone lying around was used for this. In order to create storage space for the later oven utensils, a C-shaped wall was erected. With iron rods for stabilization the free space was covered with a further 30 cm coral layer.
Important things like a suitable oven door, heat-resistant glass and the stones could not be procured during this construction period.
One of the biggest time expenditures is the procurement of individual parts, which is often very tiring. But then the next time I will be there again.
oven chamber
The oven chamber was placed on the foundation. With the assumption that it would be possible to get stones of every kind and size, if not in Zanzibar then in Dar es Saalam, the interior was designed generously according to the foundation.
But there were difficulties in choosing the oven door already. Since customizing this for the first prototype seemed too expensive. A used oven door should be used. Their procurement took a total of two months, since there were other work to be done in the garden of wonders.
In the end, the ofen body is oversized, yet as an exhibit it fits very elegantly into the garden.
glas & stone
Obtaining the stones was even more difficult than finding the oven door. A granite manufacture in Dar es Saalam could only be found after six months. It took another month and a half to order and deliver. It was similar when ordering the heat-resistant glass. The choice has now been made for a tempered glass, as there is no oven glass to buy in Tanzania itself. For a further development of the furnace, another major material procurement research will probably be pending. Now the first thing to do, is to complete the prototype. For this purpose, the interior of the oven was made twice as small as the granite, in particular, could not be supplied in the appropriate size.