Power to the People
Recently our little electric utility, San Miguel Power Association, said they were moving into the 21st century by installing smart meters. The idea is that these can transmit the meter reading to the utility’s billing system over the power lines. SMPA can save money it now spends hiring meter readers. Sounds simple and effective, right? It is!
Argh! Not so fast! The FUD (fear, uncertainty, and doubt) started flying immediately. People came out of the woodwork to claim that these meters are dangerous to the point of making people sick. The RF (radio frequency) energy they spout will kill us all! (Well, that’s a bit of an exaggeration, but it makes just as much sense as the “make people sick” claim.)
Letter to the Editor
I wrote a letter to the editor, which I here quote in full
Ever since SMPA announced their smart meter program, folks have been writing letters to the editor decrying the RF energy (also known as electromagnetic fields, or EMF) emitted by these devices. But it’s the amount of RF energy that’s important, not simply the fact that they emit RF.
We are bathed in RF energy. The sun is a huge source–it doesn’t just give us light. AM and FM broadcast stations emit copious quantities of RF. Your cell phone emits RF. The cell phone towers do likewise. Your garage door opener uses RF. Public safety officials communicate using RF. The wireless broadband service from Ouraynet and Skybeam emit RF energy, as do the Dish satellites. If you or your neighbors have a wireless home network, you get sprayed with that too. It’s everywhere!
But how much is too much? As a ham radio operator (and an electrical engineer), I was trained on harmful RF emissions. RF damages the body through heating. Think of it: you put a TV dinner in the microwave and nearly a thousand watts of RF cooks it. A thousand watts is a million times a milliwatt, which is about the power level the smart meters actually radiate (most of their RF is conducted away over the electrical feed lines). Frankly, a milliwatt isn’t going to cook anything. That’s less power than your cell phone puts out. And, the power that your body absorbs drops off as the square of the distance from the RF-emitting device, meaning that if you move a device that’s one foot from you to two feet, you cut the amount of RF you get by a factor of four.
I challenge anyone who claims to be “EMF sensitive” to a double blind test. You and an observer sit in a room. I’ll sit in the next room with another observer and turn an RF-emitting device on and off at odd intervals. Can you tell whether it’s on or off? There’s no way on the planet you’ll figure that out! The human body is simply not sensitive to milliwatt levels of RF energy.
Let’s get some sense back into this debate. Smart meter technology is here to stay. A meter that can be read from afar is not the same thing as demand pricing (it takes a different kind of meter). There really is some science at work here, not to mention economics. I’m happy to be the myth buster.
(By the way, this is the second time I’ve issued the double-blind test challenge. No one has yet taken me up on it.)
RF Over Power Lines Has Radio Interference Issues
I’m afraid SMPA didn’t help its case by saying (and I’m quoting from the Ouray Plaindealer, the local newspaper) that it transmitted the information back to home base at 60 Hz (Hz is cycles per second—the name comes from a German researcher named Heinrich Hertz), which is the basic frequency of our AC power lines. Well, that’s impossible. It has to be at a frequency high enough to make its way along the power lines back to home base, presumably helped out by repeaters here and there. You see, those great big transformers up on the poles are designed to pass 60 Hz electricity through, not higher frequencies.
Now the utilities are not exactly clean when it comes to transmitting data over power lines. Some utilities have gone so far as to advocate “broadband over power lines” (BPL), which is just as you might think—Internet via your power plug. They claim that all the energy used by the BPL equipment (and these smart meters are not BPL, strictly speaking, but the idea is the same) stays on the power lines. It doesn’t. Those long wires act as antennas and some of that power leaks away into the air. But…and I emphasize this but…the outcome is interference with radio systems in the high frequency range (for example, ham radio, shortwave broadcasting, military and civilian uses). In order to even find out that this interference is there, powerful shortwave receivers pick up the itty-bitty signals and you can hear them on the loud speaker. Of course, those same radios are looking for itty-bitty signals from other legitimate users. Because of this interference problem, BPL systems aren’t very common.
Let’s talk about frequencies. The frequency (measured in Hz), is how rapidly something vibrates. Think of your friend’s piano. Pressing the A above middle C generates a sound at 440 Hz. Higher keys generate higher notes. The range of good (really good) human hearing is perhaps up to 20 thousand Hertz, or 20 kilohertz (kHz). Anything above this is in the province of Radio Frequencies, which start around 30 kHz and go on up to where the RF becomes light, then ultraviolet, and finally cosmic rays.
What does this have to do with smart meters? They have to transmit their data using radio frequencies in the 500 KHz range (on the dial of your radio, that’s just below the lowest AM radio station). The way the system is set up, by far and away most of the power goes down the power lines, and a tiny bit leaks out into the air.
Cook a Chicken!
How bad is this? Well, the RF power used is on the order of milliwatts. How big is this? You have a microwave oven. When you nuke your TV dinner, you’re spraying it with about a thousand watts of microwave RF (on the order of 2GHz, for the technical types). A thousand watts—makes for a good heater! The microwave works because it makes water molecules vibrate in such a way as to generate lots of heat, which then cooks whatever is near it. Now remember that, a thousand watts.
To see the difference between the thousand watts of cooking energy, and the milliwatt level of the smart meters, try this experiment. Walk someplace where you can walk a kilometer (one thousand meters, or just over 3,000 feet). Look back at your starting point. Quite a ways away, isn’t it. Well, a millimeter is about the thickness of a penny. Take out a penny and compare the thickness of the penny with the kilometer you just walked. Itty bitty, tiny, insignificant, not very much. Although, of course, you can be proud that you walked a million of anything, for 1 kilometer is one million millimeters.
Let’s go back to the chicken example. A thousand watts (comparable to your long walk) is one million times as much energy (think of the penny) as the smart meters are putting out. And, of course, only a small part of the smart meter’s energy is spraying into the air.
Now, if you had a million smart meters, could you cook a chicken? No. As it turns out, the amount of effect that RF energy goes down as the square of the distance you are away from it. Now I’d have to go into some heavy theory here, complete with equations, but let it suffice to say that if you double your distance from the smart meter, you cut your exposure by a factor of four.
So, bottom line. Can these smart meters make you sick? I suppose if you ground one up in your blender and ate it, you’d be pretty unhappy afterwards, but otherwise, no way!
And anyway, we’re bathed in RF energy all the time. Remember the cell phone in your pocket? It’s a radio, putting out a few hundred milliwatts or less—yep, right into your head. AM, FM, and TV broadcast stations spray millions of watts into the air hoping that you’ll be able to pick up some microwatts (one thousandth of a milliwatt) with your AM, FM, or TV receiver.
The nastiest emitter of RF energy is the sun. It doesn’t just radiate light. You’re well aware of the dangers of ultraviolet radiation, and that’s why you use sunscreen (you do, don’t you?). Further, at frequencies below light we find the infrared, what we usually call ‘heat.’ Want to feel the heat? Stand in the sun! Does it warm you up? You bet it does. In fact, on a clear day, and just keeping to light frequencies we can see, the sun sprays a kilowatt on an area of one square meter (about ten square feet). Yep, that’s enough to cook a chicken, and if you’ve ever used a solar oven, you know just how this works. (Back to that sunscreen—you really do use it, don’t you?)
Let me tell you. A couple milliwatts of stray energy from a cellphone, your wireless computer link, and so on for the many emitters in your vicinity, just aren’t going to add up to anything worth worrying about. So get that smart meter and join the 21st Century!