There are a zillion solar cooker designs in the world, ranging from extremely cheap and so\imple to very high tech. Here's some: Some (but not most) would operate to some degree on an overcast rainy day. I have observed (and burnt my hand on) steam coming out of an evacuated tube solar heater system under such conditions and at least one design here uses these. Plans for 31 simple solar cookers http://solarcooking.org/plans/ More. Some VERY real - see eg Helios Bread Oven !!!!!!! http://solarcooking.wikia.com/wiki/Category:Solar_cooker_plans Index page by over type with links to other pages 37 designs listed here http://solarcooking.wikia.com/wiki/Compendium_of_solar_cooker_designs 130 designs Vast range - from trivially simple to rather high tech, http://solarcooking.wikia.com/wiki/Category:Solar_cooker_designs Novel. Cooksack. 7" foldup and 12 ounces (200mm 340g) Oven proper is 34g. Read between the lines suggests it has issues which are being looked at. http://www.terra.org/cocinas/fichaen.php?id=88 What works - report http://solarcooking.org/research/Dormio-report.htm Winebox cooker - transitioning to square foot paste up mirror cooker. Credibly high performance claimed http://solarcooking.wikia.com/wiki/Winebox_Solar_Rice_Cooker Winebox version construction details and discussion Jar in jar adds substantially to performance (probably) http://transitionreno.ning.com/group/simplesolarcooking/forum/topics/the-cheapo-winebox-cooker 80 designs from various sources http://www.terra.org/cocinas/searchen.php?tsearch=&fam=&prod=&pag=1 Fresnel Some good prospects http://solarcooking.wikia.com/wiki/Fresnel_solar_reflectors I like the DATS cooker - 2nd item down http://diyenergy.blogspot.com/2007_08_01_archive.html __________________ Needless to say, if you can cook food you can pasteurise and even sterilise water as well. Russell -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist