2. Overview of sessions
1. Theory of Solar Energy/Cooking
2. Solar –v– Wood/gas
3. Design features of Solar Cookers
4. Case Study in Peru
5. Successful initiatives
6. Practical session
5. Why is Solar Cooking
Important?
2,000 million cook with wood (TFL)
20-25,000km2
of forest lost/year (UNEP)
Contaminated water = 80% illnesses
ARI (Acute Respiratory Infections)
Solar Cooking = no wood & no smoke
10. Wood/Gas – V – Solar
Wood Burners or Gas Solar Cookers
Disadvantages Advantages
Takes time to collect wood,
and is using up natural
resources.
Solar energy is free
Smoke filled rooms = ARI
(Acute Respiratory
Infections)
Smoke free cooking
11. Wood/Gas – V – Solar
Wood Burners or Gas Solar Cookers
Advantages Disadvantages
Cook any time.
Day/night/cloudy.
Only cook when it is sunny.
Gas is instantaneous and
controllable.
Box cookers take time to
heat up. Parabolic cookers
need frequent adjustment.
Cook summer and winter. Need to store cooker in
rainy season.
12. Parabolic – Design Features
Size of reflector
Reflectivity of
reflector
Accuracy of reflector
Emmisivity of
cooking vessel
13. Energy Calculations
Area = 1 m2
Power = 700 Watts
1 litre of water = 7 to 8 minutes
Temperature at focus =
420 deg C. (small black thermocouple)
14. Box Cooker – Design
Features
Greenhouse principle
Area of collection
Transmission of
glass/plastic
Emissivity of cooking
vessel
Insulation of box
WAPI (Water Pasteurisation
Indicator)
15. SUNSTOVE ® Design
Low cost enclosure
Sloped side walls, scrap Aluminium
Fibreglass insulation
Clear glass/plastic cover
80 – 100 deg C
10,000 in SA & India
16.
17. Parabolic – v – Box Cooker
Parabolic Cooker Box Cooker
Disadvantages Advantages
Needs frequent
adjustment
Adjust once an hour.
More likely to be dazzled
by reflected light.
Much less reflected light.
Unstable Very stable
18. Parabolic – v – Box Cooker
Parabolic Cooker Box Cooker
Advantages Disadvantages
Very high temperatures. Only 80 – 100 deg C.
More like a BBQ or Grill Cooking takes much longer.
Easy to see it cooking
quickly.
Not too sure it is working!
(WAPI – 65 deg C)
19. Trip to Peru
10 teenagers
£30 of materials
Woodwork
Cardboard
Metalwork
Fun time
20. How did it go?
Workshops
Language!
New skills
Too small!
Too big!
Rainy season
Years later….
21. What makes an Initiative
Successful?
Choosing the right
design for the right
location.
Not this one for
£750 in Australia!
22. What makes it successful?
Over 4kWhr per m2
per day.
e.g. India, China, South Africa.
Robust, easy to use.
Perform well/efficient.
Local materials.
Very low cost.
25. What makes an Initiative
Successful?
Marketing & contacts with organisations
Existing charities
NGO’s – sustainable development
Government initiatives
Demonstrators – evangelists
Local entrepreneurs
Empowering the right people