Peter Morgan is a researcher and scientist, born in Northamptonshire, England, but for the past 40-50 years, living and working in Africa. In a situation where a third of the world's population are still without improved sanitation, his inventions include a latrine that serves millions of people in Africa and around the world. He has also designed a way to upgrade a traditional family well to improve the water quality, and a pump that can help bring up water from 30-40 metres down, but is simple to use and maintain.
And the simplest one of them all, is perhaps the "hand washing device", made by a dinks can or a calabash, hoisted up on a piece of string, and with a few holes in it, so that water can come out.
"You could argue that hand washing is equally important as having a toilet. The hands are the main carries of bacteria, and if there isn't a hand washing device that can easily spread in the community," says Peter Morgan.
Peter Morgan's inventions all have in common that they should be easy to use and maintain. Such as his bush-pump, where the number of wearing parts are so few that it lasts longer.
The upgraded family well design is equally simple, and can improve even the most basic well significantly. Basically it makes sure the well is covered and has a channel to lead off the waste water.
"Even that simple improvement, which actually could be done with a bag of cement - it improves everything, it improves the safety and the quality of the water," he says.
Providing a simple - and cheap - design is essential, as there is much proof that several small family wells are more sustainable, than a bigger, more costly communal well.
Coming to Stockholm for Water Week is, and has been very inspiring, says Peter Morgan. He says it is important that several different approaches and technologies come together to find new solutions to water and sanitation problems around the world.
"If there wasn't something like a Water Week, I don't know if those new concepts could emerge or be sown so they grow. I think probably the best work is made over coffee or over a beer," he says.
The Executive Director of the Stockholm International Water Institute Torgny Holmgren is pleased that the water week has grown and attracted more interest over the 23 years that it has been running. But to grow too much would not be good.
"We need to have interaction between participants. That is why it is so attractive for people from all over the world, to come here because they know they will meet counterparts and people from different sectors dealing with water issues. The size is not what matters, but the quality and the content of the week," he says.
This year's theme is co-operation, in line with the UN, which has declared 2013 to be the international year of water cooperation.