OPTIMIZATION OF SOLAR OVENS
IN TANZANIA
Final Design Recommendation
Side-by-Side model, black inner box
• Outer box
Problem Statement
The goal of the Solar Circle project is to design and
manufacture a solar oven that can be produced in Tanzania
primarily with domestic materials at a reasonable cost. The
oven must be easily manufactured and aesthetically pleasing
to the people of Tanzania and perform to an acceptable
standard.
Project Background
Solar Circle Organization
• Based in Okemos, Michigan
• Non-profit organization producing affordable solar ovens for
people of Tanzania
Tanzania
• Located in East Africa on Indian Ocean between
Mozambique and Kenya
• Wood and wood charcoal used for cooking
• Contributes to high rates of deforestation
• Smoke inhalation can result in respiratory disease
• Average annual income less than $500 per year
•
Group Members: Allison Lewis, Stacie Proctor,
Gerard Westover, and Matthew Winkley
Project Sponsor: Ms. Judy Martin
Faculty Advisor: Dr. Craig Somerton
Testing
Prototype built prior to trip to Tanzania to familiarize team with
manufacturing methods
Prototypes built and tested in Tanzania to allow for two pots
• Stacked design, reflective inner box
• Stacked design, black inner box
• Side-by-Side design, reflective inner box
• Side-by-Side design, black inner box
•
•
•
Modeling and Research
Air Temperature Comparison- March 12th
-One Pot-
•
1400
250
2
1000
Solar Flux (W/m )
1200
Temperature (' F)
Matlab model and research were used to optimize the
following components:
• Inner and outer box material and dimensions
• Insulation thickness
• Seal design and material
• Collector material
• Number and shape of the solar collectors
• Collector tilt angles
200
800
150
600
400
100
200
50
0
0
Solar Radiaton vs. Month
- North, East, and West Facing Collectors -
20
40
60
80
100
120
140
160
180
200
220
240
260
Time (min)
Side-by-Side Reflective
Stacked Reflective
Side-by-Side Black
Stacked Black
Solar Flux
650
Solar Radiation (W)
600
Testing Conclusions
550
500
450
400
350
300
ec
D
ov
em
be
r
em
be
r
er
ct
ob
N
Se
p
O
te
m
be
r
us
t
Au
g
ly
Ju
ne
Ju
M
ay
Ap
ril
M
ar
ch
ar
y
br
u
Fe
Ja
nu
ar
y
250
Month
N,E,W = 55
N,E,W = 60
N,E,W = 65
N,E,W= 70
Optimization Example
Tilt Angle: North, East, and West Facing Collectors
• 55˚ optimal April through October, ineffective otherwise
• 60˚ most consistent for entire year
• Solar flux is inconsistent due to varying conditions
• Painted, black, inner box maintained a more consistent interior
air temperature
• Side-by-Side designs out-performed Stacked designs
• The Side-by-Side, black inner box design reached a maximum
interior temperature of 270°F
• Height of oven was reduced after measuring pots in Tanzania
Linear Low Density Polyethylene
558 mm wide, 558 mm long , 241 mm tall
Inner box
Aluminum Lithograph
420 mm wide, 420 mm long,153 mm tall
Insulation
Kapok
Thickness: 64 mm
Seal
Shoe Rubber
12.7 mm wide, 445 mm long, 8 mm tall
Collectors
Anodized Aluminum Alloy
• East, West, and North Facing Collectors
Permanent
60˚ from horizontal
• South Facing Collector
Adjustable
50˚ from horizontal October through March
60˚ from horizontal April through September
Weight
12.5 kg (27.5 lbs)