Have you ever been so hungry that you’ve rushed over to the vending machine to appease your ravenous appetite, only to discover that it was out of your favorite snack?
Disappointing, yes. But vending machines are kind of dumb like that.
Singapore-based Semitech Semiconductor is actually working with a vending machine company in Japan to improve how the machines communicate with the grid. Typically, vending machines must have a phone line to help the owners keep track of the food supply. This is where communication is critical. It would be so much easier if the machine could talk to the owner through the power line.
One way to get devices to talk to each other is to go through the power line -- tap the existing power infrastructure already in the home and throughout the power distribution network. But power lines weren’t exactly designed to transmit data. Power lines are meant to transfer power, so the signals they carry tend to be pretty noisy.
There’s no way to predict the level of noise at any given time. All electronics -- laptops, hair dryers and televisions -- contribute in one way or another.
Today, Semitech introduced a new communications chip than can help sort through this noise. Called the SM2101, the chip is expected to be used in Advanced Metering Infrastructure (AMI) and Automated Meter Reading (AMR) applications.
Mike Holt, the vice president of sales and marketing at Semitech, claimed that “power line communication is the cheapest and most promising way of connecting the grid.”
Noise that bursts or is impulsive can destroy data. The SM2101 can actually correct these kinds of errors. The chip is flexible, as it allows the user to pick frequencies that would allow for communication, yet avoid the noise.
“Semitech provides chips that communicate over noisy power lines, where no other chip can work,” said Holt. “It’s not a controlled environment, but we are trying to communicate over a computer network,” he said.
All the different equipment plugged into outlets and all of the different standards in place make communication over the smart grid difficult. (Tres Amigas will help transport different types of electricity from one region of the nation to another.)
“Our advanced communication ability allows for communication over longer distances, higher throughputs, more meter readings per day and more transfers,” Holt said.
The new chip is built with proven technology (as it uses Semitech’s previous line of chips). It gives the user the choice of two communication frequencies to transmit and receive data, so it doesn’t interfere with the power line signals. It can also figure out the amount of noise present based on the packets received.
For instance, think about how this technology could help cities control streetlights. “Many cities in the world are going to use power line controlled street lights,” Holt said. Instead of having five people drive around to figure out if the lights need to be changed, the power line could do it automatically.
Utilities in China are more interested in using power lines to help with smart meter readings and control devices across the grid. Other competitors in the space include Texas Instruments and Echelon Corporation. “But we are the only company that has deployed medium voltage noise cancellation in China. We have proven interoperability across different products,” Holt said.
Power lines are a great communication standard and are popular in Europe, but implementing the technology can be quite pricey. Some electric companies like Centerpoint tried to use it but found they could only afford it if they passed the cost onto the customer. (See Why pick WiMax mesh over power line networking cost and Why anonymous is the next big player in smart grid for more on this topic.)
Needless to say, the market for power line communication is growing in Asia and Europe, but remains a rather hard sell in the United States.