Germany’s biggest energy company, RWE, owned all this, but that changed earlier this month when RWE’s renewable-energy offshoot, Innogy SE, hived itself off in what was Europe’s biggest initial public offering (IPO) since that of Glencore in 2011. The IPO is a consequence of years of falling profits at RWE’s conventional power generation core business, which is coming under intense pressure from wind and solar energy. Frightened by the high cost of storing radioactive waste when Germany’s last nuclear power stations go offline in 2022, investors have dumped the German utility’s stocks, leaving Innogy with a market capitalisation more than twice that of its RWE parent.