Health effects of wired PLC electrical meters
Many people are now familiar with the health issues associated with wireless
smart meters. Some suggest that wired smart meters are a better alternative.
However, the most commonly used wired smart meter technology is not safe
either and may in some cases be worse.
Keywords: power line carrier, power line communication, wired smart meters,
PLC meters, PLC smart meters, health, dirty electricity, PLT
Electrical meters using PLC technology communicate by transmitting signals via
the electrical wires. The PLC signals are “dirty electricity”, which turns the
household wiring and the power lines in the streets into giant transmitting
antennas.
Opting out of a PLC meter may not provide any relief, as the PLC signals can still
enter the household from other PLC meters and equipment in the area.
There are scientific studies linking dirty electricity with long term health effects.
A few people are so hypersensitive to dirty electricity that they had to move out of
their home after a PLC meter was installed.
The rest of this article provides more details, as well as references to more
in-depth material, scientific studies and government reports.
PLC electrical meters
PLC stands for Power Line Carrier or Power Line Communication. It is a method
to transmit data using existing electrical wires in a house and along the street. The
signals create a disturbance in the electricity, which is picked up by a receiver
somewhere else on the line.
PLC can be used several ways. The most common is for the meter to send
messages to the utility about how much electricity is consumed. These signals
travel along the electrical distribution line to a receiver. The receiver is usually at
the substation, but it may be hanging on a utility pole.
In some versions, called PLC smart meters, the utility can also send signals to the
electrical meter. These can instruct the meter to disconnect the power to the house, do an instant reading or download new software to the
meter’s built-in
computer.
These types of PLC are mostly used in rural areas and small towns. In densely
populated areas, the utilities often prefer to use wireless meters.
Some pre-pay meters use PLC to communicate with a display panel inside the
house.
There are hybrid smart meters available, which communicate using both PLC and
wireless. These may communicate with the utility via PLC, while they “talk” to
the gas meter, water meter and household appliances using wireless.
PLC turns the wires into giant antennas
Communication is normally transmitted on cables designed for it. Examples are
telephone cables, coaxial cables and cables for computer networks. These are all
designed to limit the radiation from the signals.
The electrical wires in homes and businesses, as well as the power lines along the
streets are not designed to carry communication signals. Here, the PLC signals
turn the wires into giant transmitting antennas. This is caused by the modification
of the electrical and/or magnetic fields created by the PLC signals.
The utilities claimed that there is no such “antenna effect”, but when radio
amateurs complained about interference with their radios, the U.S. Federal
Communications Commission (FCC) looked into the matter. The FCC Laboratory
did measurements on seven PLC systems, and found that all seven of them
radiated. Three of them even radiated at or above the radiation limits.1,2 Those
PLC systems were not used for smart meters, but the principle is the same.
Government agencies in Japan and several European countries also found that PLC
systems turn power lines into transmitting antennas.3,4,5
The British Broadcasting Corporation documented that household wiring can also
radiate PLC signals.6
Please see reference 5 for a more detailed coverage of this antenna effect. It also
provides many additional references, including several articles from engineering
journals.
The dirty electricity also comes from the neighbors
The dirty electricity is not just coming from the PLC meter mounted on the house.
It can also come from other meters in the area, travelling from house to house as a
disturbance in the line voltage.
Utilities have claimed that this doesn’t happen, but the U.S. National Institute of
Standards and Technology (NIST) thinks otherwise. NIST realized that signals
from various PLC equipment in neighboring houses could interfere with each
other, so NIST created a workgroup to make sure different vendors’ PLC
equipment can co-exist. The rationale for the workgroup is very clear: that PLC
signals can travel from house to house.7,8
The distance that a PLC signal can travel along a power line varies greatly. The
Turtle TS1 system can sometimes reach up to 100 miles (160 km).8 Some PLC
systems are blocked by a building transformer, while others are not.
Most modern PLC systems are two-way, which means that the utility broadcast
signals out to all meters. These broadcast signals reach all houses, even those
which do not have a PLC meter.
This all means that a household that opts out of a PLC meter may not get any
relief.
The dirty electricity is constant
Some PLC meters transmit 100% of the time. The vendor of the Turtle TS1 and
TS2 systems boasts that their meters are "always on"9 or in "continuous
communication"10, so the utility will quickly notice if there is a line break.
Other PLC meters, such as TWACS, may transmit every 15 minutes or less
frequently. However, there can be thousands of meters on the local grid, each of
which needs to transmit. The signals from many of those meters may reach into a
home.
The TWACS system polls each meter in turn.11 A controller at the substation
sends out a broadcast signal each time a meter needs to be read. These broadcast
signals will reach into all homes — the system wouldn’t work if they didn’t.
This all means that even if the meter on a house doesn’t transmit much of the time,
other parts of the PLC system do, so there can still be a constant presence of dirty
electricity inside the home.
Dirty electricity can be a health hazard
There have been a few studies of health effects from dirty electricity, though the
field is very new and has not attracted much funding. What is available now
provides cautionary information, however.
Research in Canada has found that dirty electricity appears to make elementary
school students more disruptive and less attentive, and that people with certain
types of diabetes have trouble controlling their insulin levels.12,13
An epidemiological study of a California middle school investigated a cancer
cluster there. Some of the classrooms had high levels of dirty electricity and most
of the sixteen teachers who developed cancer taught in those classrooms. The
study concluded that the cancers were associated with the dirty electricity.13,14
There have been several studies looking at biological effects from low-frequency
(ELF), pulsed and modulated signals.16 They are not directly looking at dirty
electricity, but some may still be relevant for PLC systems.
The only study specifically looking at PLC was done in Italy. The study
documented that PLC signals radiate from power lines and put forward some
theories about how they can affect humans.16
The International Commission for Electromagnetic Safety (ICEMS) is an
association of independent researchers in the field of health effects from
electromagnetic radiation. In 2006, this organization issued a statement cautioning
against PLC systems. The statement was signed by 31 scientists from 23
countries.17
The World Health Organization concluded in 2002 that low-frequency magnetic
fields may cause cancer. In 2011, they extended that conclusion to radio
frequencies as well.18
Some people are hypersensitive to dirty electricity
Dirty electricity from PLC meters does not affect everyone. Most people do seem
to do fine. Just as some people can smoke all their lives and live to old age, or
some tolerate heat or cold or noise better than others, so it is with dirty electricity.
A small subset of the population is particularly sensitive to electromagnetic
radiation at extremely low levels.19,20,21 People with electrical hypersensitivity are
likely the group most affected by dirty electricity. Some people have been
bothered so much by PLC meters, that they could not live in their homes.22,23
Electrical hypersensitivity has come to the attention of the health authorities only
in the last couple of decades and limited research is available. It is a complex
syndrome, where the symptoms and level of sensitivity can vary greatly from
person to person.
PLC systems can generate both pulsing magnetic fields and pulsing electrical
fields. Some emit low frequencies, some higher frequencies. Studies of people
who are electrically hypersensitive show that they can be affected by both
electrical and magnetic fields of all frequencies used by PLC systems (ELF to
RF).24,25
Several studies have found that about two to five percent of the population
consider themselves to be electrically sensitive to some degree.20,26,27 The number
of people severely affected is much lower.
Regardless of how few or how many people are affected, it is not reasonable to
impose such a heavy burden upon the affected individuals.
Noticing health effects is difficult
Electrical utilities have stated at various public meetings that there have been few
or no complaints about PLC systems. Thus, they contend, there is no problem. It
is not that simple:
This all means that it is very difficult for an individual to discover that they are
affected by a PLC system.
Some people have been able to make the connection, usually because their
symptoms come on rather rapidly when exposed, or are more severe. Some have
complained to their utility, but found that their complaint is ignored or even
ridiculed.
An observant local physician may notice an increase in patient complaints and
make the connection, but it is unlikely. It may take years for the symptoms to
ramp up in a local area, since PLC meters are often installed gradually over many
months. Physicians are usually busy people, so they may not notice such a trend.
Epidemiological studies will be necessary. These are difficult to do correctly, take
years to do, and cost a lot of money. None have been done so far on PLC systems.
PLC radiation may be impossible to escape
With wireless smart meters, it may be possible to stay away from the radiation by
sleeping in the other end of the house or apartment. Or, the meter could be moved to a pedestal in the yard. Or, the utility may allow an opt-out.
In many cases, there are solutions for people burdened with a wireless meter.
With PLC meters, mitigation is much more difficult.
An opt-out may not help, as PLC signals can still come into the house from the
outside. The signals can get inside on the utility line and also as direct radiation
from an outside power line near the house.
Every room in the house that has electrical wires in the walls can be affected, so it
may not help to spend more time in a certain part of the house.
A buried line radiates much less than an aerial line, but it still carries the PLC
signals into the house, where they can radiate from the household wiring.
The PLC signals may travel in the soil itself, especially in built-up areas such as
cities, towns and suburbia. In that case, a person may get no relief from being in
the yard.
Some PLC systems used in Europe can be blocked by filters. The PLC systems
used in North America use lower frequencies, which cannot be filtered.
A safe distance for people who are hypersensitive to dirty electricity has not been
established, and is likely to vary greatly with the person and situation. In one
case22, it was about 50 ft (16 meters) from a house in the country.
Filtering is difficult
Filters have been developed to mitigate PLC meters in Europe.28 These filters may
not be usable in North America.
Filtering is more difficult in North America, due to two technical obstacles:
This may make filtering on North American homes unaffordable, or simply not
practical.
Wired PLC may be worse than wireless
The health issues with the wireless smart meters have received the most attention,
and some utilities promote PLC meters as a positive alternative. With PLC meters
being more intrusive and much harder to mitigate, some people may be better off
with the wireless meters in their neighborhood. Neither technology is as healthy
as the traditional mechanical meter without transmission capability.
For more information
More information about smart meters, dirty electricity and PLC systems is
available on www.eiwellspring.org/smartmeter.html
www.eiwellspring.org/demenu.html
and www.eiwellspring.org/plc.html.
2013
References
(1) The FCC finds power line communication exceeds radiation limit,
www.eiwellspring.org/plc/FCC_investigates_PLC.htm
(2) Federal Communications Commission, ET Docket 04-39, April 29, 2009,
www.eiwellspring.org/plc/FCClaboratoryBPLreport.pdf (large file).
See reference 1 for direct links to FCC website files.
(3)
Measurements of Harmful Interference in the HF-UHF Bands Caused by
Extension of Power Line Communication Bandwidth, Fuminori Tsuchiya et
al., IVS CRL-TDC News, No. 21, November 2002.
See
also http://www.eiwellspring.org/plc/PLC_test_in_Japan.htm for
interpretation.
(4)
Assessment of Radio Disturbance Generated by an Established PLC-Network
at the Swiss City of Fribourg, Pascal Krahenbuhl and Robert Coray, Swiss
Federal Office of Communication.
See also http://www.eiwellspring.org/plc/PLC_Fribourg.htm for comments.
(5)
Power Line Communication turns electrical wires into antennas,
www.eiwellspring.org/plc/PLC_antenna_effect.htm
(6)
PLT and broadcasting — can they co-exist? BBC R&D White Paper WHP
099, J. H. Stott, 2004
See also www.eiwellspring.org/plc/PLCAntennaEffectDemo.htm for
interpretation.
(7)
NIST Smart Grid Collaboration Wiki PAP-15,
collaborate.nist.gov/twiki-sggrid/bin/view/SmartGrid/PAP15PLCForLowBit
Rates
(scroll down to “Why Is Coexistence Important”)
See also for commentary:
www.eiwellspring.org/plc/PLC_travels_into_homes.htm
(8)
For the Grid and Through the Grid: The Role of Power Line Communications
in the Smart Grid, Stefano Galli et al., Proceedings of the IEEE, June 2011.
http://arxiv.org/pdf/1010.1973.pdf
(9)
Product Specification Sheet TS1 Residential Endpoints,
http://style.landisgyr.com/apps/products/data/pdf1/TS1_Residential_ProdSheet1.pdf
(10)
TS2 PLC Network Solution, page 2,
http://style.landisgyr.com/apps/products/data/pdf1/PLCBrochure.pdf
(11)
According to SMPA utility disclosure at public meeting in Ridgway,
Colorado, December 14, 2011
(12)
Dirty Electricity and Electrical Hypersensitivity: Five Case Studies, Magda
Havas and David Stetzer, World Health Organization Workshop on Electrical
Hypersensitivity, October 2004
(13)
Dirty Electricity, Samuel Milham, iUniverse, 2010
(14)
A New Electromagnetic Exposure Metric: High Frequency Voltage
Transients Associated With Increased Cancer Incidence in Teachers in a California School, Samuel Milham and Morgan, American Journal of
Industrial Medicine, 51:576:586, 2008
(15)
BioInitiative Report: A Rationale for a Biologically-based Public Exposure
Standard for Electromagnetic Fields (ELF and RF), www.bioinitiative.org
August 2007
(16) Radiofrequency Exposure Near High-Voltage Lines, Vignati and Giuliani, Environmental Health Perspectives, Supp 6, December 1997o:p>
(17)
Benevento Resolution 2006 (article 6.6), Electromagnetic Biology and
Medicine 25: 197-200 (2006)
(18)
World Health Organization Fact Sheet 193, June 2011
(19)
Electromagnetic Hypersensitivity, Steen Hviid, Townsend Letter, January
2010.
(20)
Disturbance of the immune system by electromagnetic fields – a potentially
underlying cause for cellular damage and tissue repair reduction which could
lead to disease and impairment, Olle Johansson, Pathophysiology, 16, 2009.
doi: 10.1016/j.pathophys.2009.03.004
(21)
Electromagnetic hypersensitivity: Fact or fiction, Stephen Genuis, Sci Total
Environment, 2011, doi: 10.1016/j.scitotenv.2011.11.008
(22)
Driven Out by PLC,
www.eiwellspring.org/smartmeter/DrivenOutByPowerLineSignals.htm
(23)
PLC health effect testimonials,
www.eiwellspring.org/smartmeter/PLC_testimony.htm
(24)
Electromagnetic Field Sensitivity, William J. Rea et al., Journal of
Bioelectricity, vol 10 (1&2), 241-256, 1992,
(25)
Electromagnetic Hypersensitivity: Evidence for a Novel Neurological
Syndrome, David McCarty et al., International Journal of Neuroscience, 121,
670-676, 2011, doi: 10.3109/00207454.2011.608139
(26)
Prevalence and risk factors of self-perceived hypersensitivity to
electromagnetic fields in California, Patrick Levallois, Environmental Health
Perspectives, August 2002 (vol 110, sup 4)
(27)
Development and Evaluation of the Electromagnetic Hypersensitivity
Questionnaire, Stacy Eltiti et al. Bioelectromagnetics, 28: 137-151, 2007, doi:
10.1002/bem.20279
(28)
Filtering the new smart electrical meters, Torbjorn Lindblom,
www.eiwellspring.org/tech/FilteringNewSmartMeters.pdf