Powerline network adapters sound great, but they often fall far short of their promised performance.
First, depending on "how large" your house is, WiFi almost certainly is still a viable option. It depends on what type of network you use (you'll want at least N or greater), the quality of the router, the nature of walls and floors between you and the router, external interference, and the sensitivity of the receiving antenna.
Quality consumer grade equipment should be able to maintain N+ level speeds at distances approaching 50 feet without serious degradation and still have a couple of walls between the AP and receiving PC/laptop. Many types of consumer equipment will still reach good speeds (usable Netflix and YouTube) at 80 to 100 feet. Distances approaching 125 feet are not uncommon. Again, this depends on all sorts of other factors.
That said, powerline networking offers the promise of using existing electrical wiring without having to string new Cat5/6 wiring. But, just like wireless promises, there are many other factors: the quality of wiring, the quality of the powerline adapters, and external factors.
Here are some quick pointers:
- Avoid wiring runs with GFCI or AFCI breakers. They will reduce bandwidth by over 50%.
- Avoid mixing adapter types and brands.
- Use 200 Mbps powerline adapters or better. Original powerline adapters usually throttle down to 10 Mbps or less.
- Minimize or reduce electrical interference on the circuit. Transformers or devices with transformers will often introduce noise and interference reducing bandwidth.
Because it's difficult to meet all of those criteria, most people just use wireless networking. If you meet all the criteria above, you'll probably get great speeds. But then, you might just save time and effort by running your own Cat5 wire through the house and regain the ability to use the electrical outlets again.
To quote from Harvard's Characterizing the End-to-End Performance of Indoor
The performance of a PLC device depends on the location of the power
outlet. For example, PLC devices do not work across surge protectors,
and other voltage inhibiting equipment. Also, PLC devices perform
worse in a network with more AC load, which is generated by electrical
appliances (refrigerator, blender, etc.). Consequently, power outlets
should be carefully chosen to get the best performance from the PLC
And from the same paper's conclusion:
The main contribution this paper makes is that it evaluates the
end-to-end performance of PLC networking. Out of necessity, we treat
PLC devices as black boxes. We study characteristic such as channel
symmetry, variation by time of day, impact of distance, impact of
electrical appliances and simultaneous transmitters. We ﬁnd that in a
large home environment, PLC can deliver better per formance when
compared to wireless. However, we also ﬁnd that (i) the performance is
substantially lower than manufacturer’s claims (no surprise here), and
(ii) common household appliances affect the performance signif-
icantly. Therefore, we conclude that PLC in home environments is
useful, but the user experience may vary signiﬁcantly. In other words,
we are cautiously optimistic.