Why Pick WiMax, Mesh Over Power Line? Cost.  

GreentechGrid has a post on the relative merits of wireless mesh networks vs power line based networking for smart grid communications - Why Pick WiMax, Mesh Over Power Line? Cost..

CenterPoint Energy has only good things to say about power line networking, except when it comes to the cost.

The energy delivery company conducted a trial earlier in the decade with power line networking in approximately 10,000 homes, said Ken Murphy, Director of Intelligent Grid Deployment at the company, during a talk at NI Week, a conference sponsored by test and measurement specialist National Instruments taking place in Austin. Because of the high bandwidth that power line offers, the company also gave computers to consumers who were participating in the test.

The idea was to both test the technology and see if consumers might be willing to get their internet service from CenterPoint. In Australia, some electricity retailers have started to bundle Internet, TV, phone and utilities.

The technology worked. Consumers, however, seemed indifferent to the idea of switching their broadband providers. With the potential to sell internet services off the table, power line was just too expensive compared to competing technologies.

"BPL (broadband over power line) may be the way to go if you need bandwidth," he said. "It worked well for us, but it would have been more expensive."

Instead, the company opted to install Itron meters on homes, which communicate with a lower-bandwidth mesh technology to a hub. The hubs then relay data to substations via WiMax and from there, everything gets put on fiber and sent to the utility.

"There are already a lot of internet service providers, so we decided not to get into that part of the business. Our network now is not a public system. It is only used for utility purposes," he added.