Feels like I've spent all day researching solar stills.
Take home fact: an 18' by 27' solar still in a tropical area should produce about 360 litres of drinking water a day. Not a lot you may say, but that is 131,000 litres a year, all from one greenhouse.
If one still costs, say, £1000, the UK could build 35,000 stills a week in Africa. If we stopped spending it all on paying for Trident to sail aimlessly around in the deep Atlantic, waiting to kill 50 million people with its payload, that would produce 229,250 million litres of clean water a year.
The lunatics have most definitely taken over the asylum. Yet I sit here calmly typing, and you sit there calmly reading. Ho Hum.