Moses Banda invented this solar pump. All part are worldwide available and cost a minimum. The pump is ideal for very narrow tube wells, starting at 2" casing and bigger. Suitable for wells that produce very little water because it pumps slowly but steady. After 5½ hours an overhead tank of 1000 liter is full.
Moses is a manual borehole driller trained by Jacana SMART Centre in Chipata, Zambia (https://jacanan.help)