Answer 2: Enamel is the hard material that coats your teeth, and is made mostly of a mineral. However, we call other things enamel. There's enamel paint, which is totally different, and there's also porcelain enamel, which is used to make a lot of dishes.
All of this is due to Amazon's unique approach with the Echo. It's not a portable speaker like we've seen from Jambox and Logitech. Instead, it's a rather large, cylindrical device that needs to be plugged into power. It's something you'll likely just leave in a single spot in your home.
Just like Tesla's Powerwall, the repurposed Volt batteries can provide the electricity a building needs during power outage: the five-battery pack, in particular, can supply enough energy to keep the data center running for up to four hours.