Whakarāpopototia te tuhinga:  I te tau kua hipa, neke atu i te rua te nui o te pūngao o te rā i te UK, ā, i te US kua piki ake te 30 ōrau. Engari he maha nga pūnaha o nāianei e kore e taea te whakaoti i te raruraru o te whakahaere me te whakamahi i te pūngao i te pō i te wā e hī ana te rā. Ko te tikanga, ko te pūngao i kohia i te awatea ka whakahokia ki te whatunga, engari ka nui pea te utu mēnā ka hiahia koe ki te hoko anō - ki te kore he pākahiko atamai kei a koe hei rokiroki i te pūngao nui i roto i tō whare. Ko te Sonnenspeicher (i whakaahuatia) e whakamahi ana i te papahiko lithium iron phosphate hei penapena i te kaha e whakamahia ana e nga papa o te ra. Ka taea te whakamahi i tēnei pūngao i te roanga o te rā, ā, ka penapenahia ētahi atu mō te wā ka heke te rā. Engari i te hoko i tēnei hiko nui ki te whatunga, ka taea e ngā kaipupuri whare te whakamahi i tō rātou rerenga pūngao mō te hiko. I runga i tēnei whakaaro, kua waihangahia e te kamupene Tiamana Automatic Storage Device (ASD) me te kaihoahoa Wolfram Walter te Sonnenspeicher. Ka whakamahia e ia he papahiko lithium iron phosphate hei penapena i te kaha i kohia i te awatea e nga papa o te ra e whakauruhia ana ki te tuanui. Ka whakamahia tēnei pūngao puta noa i te rā, ā, ka penapenahia ētahi atu mō te wā ka heke te rā. Hei utu mo te hoko atu i tēnei hiko nui ki te whatunga, ā, ka taea te hoko anō i muri mai, ka taea e ngā kaipupuri whare te whakamahi i tēnei pūngao kua tiakina hei whakaoho i tō rātou kāinga tae noa ki te putanga mai o te rā. Kei te Sonnenspeicher tetahi punaha whakahaere mohio e whakahaere aunoa ana i te utu me te whakaheke i te hiko, kia maama ake ai te whakahaere i te nui o te kaha e whakamahia ana. Kei te Sonnenspeicher tetahi punaha whakahaere mohio e whakahaere aunoa ana i te utu me te whakaheke i te hiko, kia maama ake ai te whakahaere i te nui o te kaha e whakamahia ana. He aratau okiokinga anō tōna e whakarite ana kia kore te pūnaha rokiroki e pau, ā, ka haere aunoa ki te tūtatari ina kāore i te whakamahia. Ahakoa i hangaia kia tino motuhake mai i te whatunga hiko a motu, ka taea te hono atu ki te waa ohorere. Hei tauira, i nga wa katoa e waatea ana te hiko i roto i te papahiko, ka raka te hononga ki te whatunga. Ka rere ana tēnei pūngao...
I hangaia a Sonnenspeicher e Wolfram Walter me te kamupene Tiamana ASD. Ko tōna pākahiko lithium iron phosphate e penapena ana i te pūngao mai i ngā paewhiri solar. Ko te tauira iti rawa ko te € 8,450 (£ 6,170), engari ka penapena moni i runga i nga pire hiko. Ka tae mai hoki me te 'pūnaha whakahaere mohio' e whakahaere ana i te mana o nāianei.