How solar stoves cut cooking smoke
21 September 2010 Last updated at 17:33 BST
The US Secretary of State Hillary Clinton has announced a global partnership to tackle the scourge of toxic smoke from indoor cooking fires.
Cooking smoke is estimated to shorten the lives of 1.9 million people a year; it also contributes to climate change.
The BBC's Roger Harrabin shows how a cleaner solar stove works.