ʻO ka makahiki 2024 kahi manawa koʻikoʻi no ka ʻoihana photovoltaic (PV) ʻoiai ʻo ka hoʻokūkū ikaika e hoʻokele wikiwiki ana i ka ʻenehana kelepona a me nā noi ʻoihana, ʻoi aku ka wikiwiki ma mua o ka wikiwiki o hoʻokahi ʻumi makahiki i hala. ʻOiai me kēia mau hana hou, ʻo ke koho ʻana o ka ʻili encapsulation—inā paha ʻo POE (polyolefin elastomer), EVA (ethylene-vinyl acetate copolymer), a i ʻole EPE—ke waiho nei i kahi kumuhana koʻikoʻi a kūkākūkā nui ʻia no nā modula aniani-aniani, pepa aniani-hope, a me nā modula maʻalahi.
Ke kū nei nā modula PV o waho i ka hōʻino ʻia e nā kumu kaiapuni nui ʻehā: ka wela, ka oxygen, ka wai, a me ka radiation ultraviolet (UV). ʻOiai he mea liʻiliʻi ka hana olaola i kēia mau noi, he kuleana koʻikoʻi nā kumu ʻē aʻe i ke koho ʻana i nā mea. Hoʻohālikelike kēia ʻatikala i ka hana o EVA a me POE ma lalo o kēia mau kūlana, e hāʻawi ana i nā ʻike hou a me nā ʻano hana no ke koho ʻana i nā mea.
1. Wela
Hiki iā EVA a me POE, ke hoʻopili ʻia, ke kū i ka hoʻopili pōkole ʻana i nā mahana ma kahi o 150°C. Eia nō naʻe, palaho ka EVA i nā mahana ma luna o 200°C, e hoʻokuʻu ana i nā nui o ka waikawa acetic, ʻoiai ʻo POE e kūpaʻa a hiki i ka piʻi ʻana o ka mahana ma mua o 300°C.
2. ʻOkikene
Ma ka mahana o ka lumi, hōʻike nā mea ʻelua i ke kūpaʻa maikaʻi i ka oxidation. Eia nō naʻe, loaʻa i ka EVA nā nui liʻiliʻi o nā monomers acetic acid manuahi, kahi i maʻalahi i ka oxidation i nā mahana kiʻekiʻe. I ka hoʻohālikelike ʻana, ʻo POE, i haku ʻia me nā pilina carbon-hydrogen paʻa kemika, pono i nā mahana kiʻekiʻe loa e hana me ka oxygen.
3. Wai
Hiki i nā hui ester o EVA ke hoʻoulu i ka hydrolysis, e alakaʻi ana i ka hoʻokumu ʻia ʻana o nā hui carboxyl e hoʻolalelale i ka hydrolysis hou aʻe a me ka hoʻohaʻahaʻa ʻana o nā mea. ʻO POE, me kona kaulahao carbon-hydrogen piha, he paʻa kemika a ʻaʻole i hoʻopilikia ʻia e ka hydrolysis. Eia kekahi, hōʻike ʻo POE i ke kūpaʻa ʻoi aku ka maikaʻi o ka mahu wai, me ka helu hoʻoili mahu wai (WVTR) ma kahi o 3 g/m2·24h ma 38°C a me 90% ka haʻahaʻa pili, hoʻohālikelike ʻia me ka WVTR o EVA o 25 g/m2·24h. Hoʻonui kēia permeability haʻahaʻa i ka hiki o POE ke pale i nā ʻāpana modula kūloko mai ka hōʻino ʻana o ka makū.
4. Ka Pāhawewe Ultraviolet
ʻO ke ʻano o ke kaulahao carbon-hydrogen āpau o POE e hōʻike ana i nā pilina kemika ikaika—nā pilina CH ma 414 kJ/mol a me nā pilina CC ma 332 kJ/mol—e hoʻopaʻa ana iā lākou i ka ʻoki ʻana i hoʻokomo ʻia e UV. I ka ʻaoʻao ʻē aʻe, aia nā hui ester o EVA i nā pilina CO me nā ikehu pilina ma lalo o 330 kJ/mol, kahi i ʻoi aku ka maʻalahi o ka hōʻino ʻana o UV.
Hopena
Ma waena o nā kumu nui ʻehā e pili ana i ka hilinaʻi o ka noi waho—ka wela, ka oxygen, ka wai, a me ka UV—ʻoi aku ka maikaʻi o ka POE ma mua o ka EVA. I ka lilo ʻana o nā pūnaewele PV i mea pono a koi aku i ka hilinaʻi paʻa, ʻo POE ke koho kūpono loa no ka hōʻoia ʻana i ka hoʻopuka mana paʻa a lōʻihi i nā wahi waho.
