We had many Sparring Partners on energy efficiency in wireless, but none was on Wi-Fi. This is a glaring omission since Wi-Fi accounts for the majority of wireless traffic – in most countries, it hovers at around 80% of wireless traffic. Yet, there is much less data (and debate) on Wi-Fi energy efficiency than on 5G or LTE – and there are reasons for this. Claus Hetting at Wi-Fi NOW helped us fill this gap in the next Sparring Partners. We debated on the energy efficiency of Wi-Fi, and on how it compares to that of 5G and LTE. We also talked about how efficiency changes in different use scenarios and how we should measure efficiency.