German energy group Uniper SE (<a href="https://www.boerse-frankfurt.de/equity/uniper-se-na-o-n-1" target="_blank">ETR:UN0</a>) said on Friday that it has signed a share purchase agreement with Warsaw-listed renewables firm Photon Energy NV (<a href="https://www.gpw.pl/spolka?isin=NL0010391108#infoTab" target="_blank">WSE:PEN</a>) to acquire a 20.4-MW solar photovoltaic project in Poland.