Hacking Rooftop Solar Panels Is a Way to Break Europe’s Grid

All it takes is one hacker and a batch of faulty solar panels to threaten the safety of Europe’s electric grid.

Vangelis Stykas, a cybersecurity consultant, said he figured out how to do it. Using a laptop and smartphone at his home in Thessaloniki, Greece, Stykas bypassed firewalls in panels around the world and gained access to more power than runs through Germany’s entire system.

The “white-hat hacker,” who tests software so companies can fix flaws, said he got far enough inside the controls that he could have turned the devices off, dramatically tipping the supply-demand balance for the power network. Such a drastic fluctuation could stress ...