After asking airports around the continent, the firm found that Heathrow is among the best with 3,050 plug sockets across the departure lounges in its five terminals, or roughly one for every two of the 6,250 passengers using them at any moment in time.
Kayak didn't obtain figures from Gatwick but nearby Luton managed 400 charging points, (including 40 universal charging points), while further afield Frankfurt had 800, Munich 1,464 (plus 1,196 USB charging ports), and Barcelona 1,040.
Vienna meanwhile reported 500 ports (and 200 USBs), Moscow Sheremetyevo 1,500. What really matters is still the ratio of passengers to charging ports and on that scale most of the airports appeared to be roughly even.
Not all seem to have caught up with this consumer need however. Hamburg was a notable laggard with a paltry 77 plugs and 48 USBs while Marseille could manage only 100 plug sockets and 6 USBs, and Bologna 28 plug sockets and 32 USB ports.
These are much smaller airports than Heathrow of course - Marseille has a tenth its traffic - but it's clear that not all airport owners see this as a priority.
One factor not mentioned by Kayak is how many of the plug sockets and USB ports are available at no cost - some airports make ports available through third parties that charge passengers to use them.
Charging ports are slowly becoming a facility that can be found in public spaces with McDonalds and Starbucks providing these for customers along with Wi-Fi. One startup has even tried a business model based on offering rentable battery chargers around London.