Current declined to confirm the amount raised in the investment, but a story in yesterday’s Wall Street Journal said it was $100m.

Current is a Germantown, Maryland-based group with two divisions: Current Technologies LLC that develops the technology and products for BPL, and Current Communications Services LLC that offers services in conjunction with electrical utilities.

In March it announced the first service based on its technology in Ohio, Indiana, and Kentucky, in association with Cinergy Corp, a utility based in Cincinnati, Ohio. That venture plans to offer BPL services to Cinergy’s 1.5 million customers in those three states.

Current formed a second joint venture with Cinergy’s broadband division to deploy BPL for smaller municipal and co-operatively owned utilities, bringing the total addressed audience to 24 million. Cinergy also made an investment in Current at that time.

Current spokesperson Brian Lustig said the company would use the new investment to broaden its BPL network in the US, which includes trials in Hawaii and suburban Washington, DC, as well as potentially in Mexico and South America.

Google declined to comment about its investment beyond a prepared one-sentence statement that said Google is very excited about its relationship with Current to help promote better access to the Internet.

But the logic for the search engine’s move is clear. Google wants as many people as possible to be on the internet, as that increases its potential user base, and if BPL really takes off, anyone connected to the national grid could soon be googling.

Still, BPL is clearly gaining momentum, as first the US government’s Federal Communications Commission in February proposed rules to facilitate the deployment of BPL over the electric power grid, then this week the IEEE announced it has begun work on a standard to define the nature of the communication channel to be used with AC power lines.

The proposed standard is the IEEE P1901, Standard for Broadband over Power Line Networks: Medium Access Control and Physical Layer Specifications that is expected to be completed by early 2007.

The ability to transmit digital data over power lines from substations to homes and offices is attracting attention because it transforms wall outlets into Internet portals, said Jim Mollenkopf, co-chair of the IEEE’s BPL PHY/MAC Working Group. This approach resolves the tough task of linking long-distance fiber-optic cables to individual computers and should make the internet even more universal than it now is. If BPL is to become widespread, there is a need for a robust standard that supports the use many types of BPL devices. Our intent is for IEEE P1901 to be that standard.