Broadband over Powerlines

scubacuda writes "Today's Bottom Line links to an article on Internet-over-powerline technology. St. Louis-based Ameren Corp and other utilities are testing are testing the technology, and, according to the article, "many consider it increasingly viable." Proponents claim the powergrid technology will bolster broadband competition, lower consumer prices and bridge the digital divide in rural areas. Skeptics say that few tests prove its financial and technical viability. Kludge, panacea, or hoax? (I'd think it was a total crock had I not personally known someone working in India with a PCL company)"

Comments

Re:Leakage

[Kill da wabbit]

This ones from last year but I'm looking for a link to the problems found by the English power authorities when they trialed this tech. http://www.theregister.co.uk/content/archive/25649 .html

Oh yeah?

[CrystalFalcon]

No one seems to have cracked a proper commercial solution

Oh. I guess my 10 megabits a second from the local power company is just a hoax, then. Strange, it seems to work just fine...

In Sollentuna, Sweden, the local energy company is supplying broadband to apartments and even to ordinary houses. Yes, you read me right: these guys are drawing fiber to single-family houses at affordable cost, then lighting them up with 100 Mbits a second.

OTOH, there's nothing said about how they carry the TCP/IP. In my imagination, it's been fiber bundled with power lines. That's probably more economical than trying to piggyback..

Yeah, nice one!

[Draoi]

Network Working Group<BR>
B. Rajagopalan<BR>
Request for Comments: 3251<BR>
Tellium, Inc.<BR>
Category: Informational<BR>
<B>1 April 2002</B>

Cool - you got '+5' for an april fool's joke ... :-)

Other approaches

[panurge]

I believe that ABB, in Thailand, tried the idea of running a broadband fibre THROUGH the Earth lead of an overhead powerline. 600 000V on the phases does tend to discourage vandals from stealing the fibre.

The problem with any wire-based HF transmission system is reflections, standing waves, radiation and losses, and a power system by its very nature is not designed for HF. But the existence of the infrastructure - distribution stations, ducting, overhead supports - could make it a very good solution for stringing fibre. Overhead cables are inherently less prone to backhoe incidents than buried cables. There is a benefit to the electrical utility in that they can use the fibre to run their own control systems easily.

Any such idea needs to be planned in from the start- it could be a cheap add-on to rural electrification in places like India and China, but much harder to do in the US or Europe where cables have long service lives.

A total crock?

[Anonym0us Cow Herd]

I'd think it was a total crock

I don't know how this particular technology works. But think about how X10 works.

The power goes through a sine wave cycle 60 times each second. That means there are 120 times each second where there is a zero crossing. That is, no voltage on the wires. Just dry wires. Now widen this period of time from zero milliseconds to some positive number of milliseconds, and you now have a definite time period where the voltage on the lines is less than X. (Where X is some small desired voltage.) During this time, you can transmit a high frequency signal on these dry wires.

I know that is a vague description. It was many (like 14) years ago when I read the specs on how X10 works on the power line.

There are no doubt other techniques. So why would anyone be skeptical of the mere capability to send high bandwidth information over power lines?

Re:A total crock?

[Orne]

The current, voltage, motor speed (and torque), and AC frequency are all interrelated. Here is some good information on the web.

http://www.valhallascientific.com/applications/app lications-3.shtml

http://www.lehmanengineering.com/quiz/quiz6sol.htm l

http://www.mech.uq.edu.au/courses/mech3760/chap34/ s1.htm

Humans create "reactive load" by running motors. Motors draw current, increase in current lowers voltage amplitude across a transmission line, plus larger power flow causes increase in reactive loss on a power line. Reactive loss lowers the voltage at both the supply end and the delivery end. Lower voltages reduces the torque in the motor shaft, not to mention reactive demand reduces the real output of the generator. This tends to slow down the motor, and the rotor speed is proportional to the frequency, so the overall frequency drops.

The only difference is that there is no cat. Err, I mean, the whole concept of "reactive" energy is just a mathematical construct representing amplitudes and phase angles. Its the old A<Phi vs R+jX conversions. But they're messy.

Swedish company delivering internet via powerlines

[duran_dal]

A swedish company called ENKOM is building a net on the island of Gotland. Sadly the page is only in swedish. But they are now connecting customers. 2 Mbit/s, 10 Mbit/s under development.

Here in Ireland ..

[Draoi]

... we've already got broadband over powerlines - sorta! Our national electricity supply company is bundling fibre optic cables with high-voltage lines. They say;

The network consists of 48 fibres (24 pairs, each pair capable of delivering 2.5GB.) wrapped around the ESB's high voltage network.

Just as well, seeing as we're still waiting for ADSL

Commercially viable?

[locknloll]

In Germany, the electricity provider RWE just recently stopped its Powerline programme. If I get the numbers correct, they only managed to get about 2000 subscribers in almost three years. Talking about cash burn...

been working fine in Scotland

[netean]

I understand that Scottish Hydro Electric are successfully using this technology in two rural towns in western scotland (Cambeltown). I understand it's partly subsidised but even so it seems very fast access (2mb) and cheap (£30) http://www.ssetelecom.co.uk/latestnews/criefandcam pbeltown.asp

Done that, chucked in.

[I)_MaLaClYpSe_(I]

Here in Austria (not Australia!) tests were made with "the Internet via the outlet" over a year ago, but the tests were stopped, because there was too much interference (with household appliances) and the voltage swings turned out to be a problem, too.

Sounded promising back than and I was surely disappointed, when it was announced that it was not experimented with it any further. :-(

--Mal

How is it 'news' ?

[dago]

... when my electricity company does that for more than 1 year and that it has been already used in germany too ?

obvious link to it EEF Powernet (french/german only).

btw, it leaves me with only 4 choices for broadband (ADSL, Cable, powerline, satellite). I can't even have wireless access ... pffff ...

Ve hawe that alredy here in finland

[ConsoleDeamon]

My local Isp offer both adsl and vdsl and over power lines. :)

your talking about something different

[diablobynight]

Yes we realise that you can bundle a fiber line with a power line, that's not what this is discussing, although I am glad you are getting cheap broadband. But I think you know, because you said piggy back, this is operating a network right over your current power lines, utilizing the unused channels. I personally thought it was a great idea when I read about it 2YEARS AGO, (not exactly new /.) The issue is that, our power operates on 60 cycles per second, and this really isn't appropriate for the technology they want, now I admit they can change this at the power company with relative ease, but if you change it from 60 then you'll suddenly find that some of your house hold appliances no longer work. I hope they work this out, I think it is a neat idea, just have two power cords for your computer, one for power, one for internet. it could eliminate the need for powered switches, for IP phones.

Live

[Anonymous Coward]

in some towns in Switzerland.

http://www.allo.ch/fr/internet/powernet.php

Still a developing technology....

[Anonymous Coward]

Trials still going on in Scotland apparently [£15/mo. for 2Mib/s, sweet]. I also seem to remember seeing something recently about the technology being refined and ready for use in the UK. Apparently in the US it wouldn't be economical as each station would only serve a few people due to way their power infrastructure is set up.

Data Communication Using Power Lines (patent)

[notaspy]

U.S. Patent no. 5,554,968, e.g., FWIW.

They're testing it where I live

[yknott]

I live in Emmaus, PA and our local power company, PPL (Pennsylvania Power and Light) has been testing broadband over powerline here for a few months. My friend has it and he finds it very convenient. He gets 1.5mb 2-way for about 30 bucks a month. Of course this is just a pilot program. I just can't wait till I can get in on the action. (According to him, PPL called random people in the Emmaus area to try out the system.) This is wonderful because here in Emmaus, there is no DSL or 2-way cable modems because of the monopoly the cable company(service Electric) has over everything.

The only link I could find on PPL's pilot program was here

Quoted below:

PPL, PA

Al Richenbacher, Manager of PPL's Market Development Group, reported on
PPL's test of PLC in Emmaus, PA, working with Main.net. They chose
Main.net due to their extensive track record of trials in Europe, and the
ability of Main.net to pass their PLC signal through the transformer. I
confirmed this during Q and A--Main.net can pass their signal through a
transformer rather than couple around it.

If the trial goes well, PPL would look to go to commercial deployment in
2003.

PPL is also considering partnering with Amperion, to provide MV backhaul.
This would primarily be to service business customers with bandwidths of
T1 and below.

PPL is currently in the middle of developing their own back office
(billing, provisioning, etc), to service their PLC offerings.

Al would not reveal their total cost per customer on the trials, but
stated that it appeared to be favorable when compared to DSL and cable.

Initial penetration is expected to be less than 10%. But, with a smart
build strategy Al stated that this would be enough to pass break even.

PPL has an internal group that works with the state regulatory commission.
Conversations so far have only been preliminary but the reaction from the
commission has been positive and encouraging.

Re:Frequency is mechanically derived

[Orne]

Yes.

http://www.ecmweb.com/ar/electric_answering_seve n_ common/

"How do AC generators control vars, voltage, and power?

Although the controls of a generator do interact, the following generalities are true.

* Power output of a generator is controlled by its prime mover.

* Voltage and/or var contribution of a generator are controlled by the exciter current level.

For example, let's assume that an additional load is connected to the output of a generator. The added current flow will increase the strength of the armature's magnetic field and cause the generator to slow down. In order to maintain frequency, the generator's governor will increase the power input to the prime mover. Thus, the additional power required of the generator is controlled by the prime mover input."

And vice versa. Too much generation increases the frequency.

"As a final example, let's assume that we have two or more generators running in parallel and feeding a load. Generator 1 (G1) is carrying all the load (real and reactive) while Generator 2 (G2) is running at zero watts and zero vars. If the operator for G2 opens the prime mover throttle, G2 starts to feed watts to the system. Since the connected load hasn't changed, both generators will speed up unless G1 throttles back.

As G2 picks up an additional share of the load, it requires an increased field flux. If the G2 operator does not increase the G2 field, G2 will draw its additional excitation from G1, requiring G1 to increase its excitation level. If neither G1 nor G2 increase the excitation level, the overall system voltage will go down."

See also

http://www.ecmweb.com/ar/electric_prime_movers_v ol tage/