From the horse’s mouth
Ethernet Adaptor Product Page (Order Here)
Out of the box, the Google Chromecast connects to your home network via its integrated 2.4GHz Wi-Fi circuitry. But what use is this if the TV you are using it with is in a lounge area furthest away from your home network’s router. And the situation is made worse because you are dealing with a double-brick wall between what was the existing house and the newly-built extension. This is while the TV’s circuitry and chassis materials effectively attenuate the radio signals coming from the front. You end up with heaps of buffering because the Wi-Fi wireless signal is very poor.
You might try a cheap wireless range extender but find that you are taking it back to the store because it isn’t really effective and is a lot more difficult to deal with.
But Google has answered your need by providing an adaptor accessory that effectively gives it an Ethernet port which opens up some paths to improve the situation. This means that you could take advantage of the Ethernet infrastructure if you wired your house for Ethernet, or could use a HomePlug AV500 or HomePlug AV2 powerline-network kit to effectively provide a wired link between your home network’s router and the Chromecast-enabled TV. Even using a wireless-Ethernet client bridge that is positioned for best reception or supporting newer Wi-Fi technologies can work wonders with this device.
This adaptor is effectively a power supply for the Chromecast along with a USB-connected Ethernet network adaptor and connects to the Chromecast dongle via its microUSB port. As far as I know, the installation involved for this device would simply be a “plug-and-play” affair. But, if you are using HomePlug powerline networking, I would recommend a HomePlug adaptor with integrated power outlet to save on power outlets or a HomePlug adaptor with integrated Ethernet switch so you can allow the PS3 or Blu-Ray player to take advantage of the same wired backbone.
It didn’t take long for Google to sell out of this device in the USA so if the link says “out of stock”, check back later. This could mean that they would have to ramp up the number of units being built and reckon that it is tome to release it in to other markets.
As well, anyone who is designing a network media receiver of the kind that directly plugs in to a TV’s HDMI socket and connects via Wi-Fi wireless could make sure there is a way to connect an Ethernet adaptor to these devices and such an adaptor is available.