The technology industry has invested a lot of marketing energy and dollars into getting consumers excited about wireless power, the promise being that it will free us from the size and feature constraints imposed by batteries. There’s a consortium of bigwigs from Nokia to Dell trying to advance a standard called Qi, and Intel and WiTricity are trying to develop an even more compelling technology that will transfer power over the air. But we’re still a long way from cutting the cord.
After years of hope (and no little amount of hype), wireless power is finally getting into consumer hands. However, the technology that is showing up on trade show floors and store shelves is a far cry from the truly disruptive promise of wireless power. As we cram more computing power into our mobile phones and use them to deliver the web, take photos and shoot video (as well as talk), a key limitation has become the battery. Anyone who has experienced a three-hour battery life after surfing on a Wi-Fi network knows first-hand that battery life can impede the enjoyment of a full-featured mobile device. And that problem is the one that wireless power will one day solve.
Below is a omparison of total system effiiciencies versus transmitting range of the various technologies. Efficiency describes how much power is wasted and how much heat is dissipated during power transmission. Inductive systems have the highest system efficiencies of any wireless system.