Hi Daniel, Solar cookstoves are an interesting aspect of the set of solutions, and well worth pursuing. In fact, some of my earliest energy papers were on cookstoves (largely work done with Prof. Bill Lankford in Central America): Kammen, D. M. and Lankford, W. F. (1990) "Cooking in the sunshine," Nature, 348, 385 - 386. Kammen, D. M. and Lankford, W. F. (1990) "Comparative study of box-type solar cookers in Nicaragua," Solar & Wind Technology, 7, 463 - 472. They are very elegant solutions to specific cooking applications, but in many settings the inability to cook quickly means that they are not the technology of choice for many everyday tasks, even though for long, slower cooking, they can be invaluable. Part of the solution set, to be sure, but not the only such solution. Great question and sentiment! Dan K.