Patent ID: 8142652

Claim:
Container ( 100 ) for purification of water by utilizing sunlight, including a first section ( 110 , 210 ), which at least partly includes a sunlight permeable layer ( 111 , 211 ), and a second section ( 120 , 220 ), which at least partly is opposite the first section and at least partly includes a sunlight absorbing and infrared radiation emitting (IR-emitting) layer ( 121 , 221 ), wherein the first and the second section together enclose a volume ( 130 , 230 ), in which the water can be received to be heated by and exposed to sunlight, characterized in that the first section ( 110 , 210 ), is formed such that the permeable layer is essentially flat, and the second section is arranged such that the volume includes at least a first and a second portion, wherein the first and the second portion, respectively, have a first and a second distance, respectively, between the permeable layer ( 111 , 211 ) and the sunlight absorbing and IR-emitting layer ( 121 , 221 ), where the first and second distances are mutually different, wherein a temperature difference between the water in the first and second portion is created after a period of sun exposure.