While the Smart Grid is getting a lot of attention and wireless will play a major role, utilities will need to carefully examine myriad technologies and networks before making decisions.
It’s a term that has become a staple of pundits, politicians and television “corporate image” ads: Smart Grid. By now, I’m sure that the vast majority of Americans have heard of the Smart Grid and understand that it has something to do with our electric power system. But from what I can tell, most of us have at best a hazy understanding of just what the Smart Grid is and what it will do.
Interesting, you might say, but what does this have to do with wireless? Plenty. In fact, wireless data communications will almost certainly prove to be vital for operation of the Smart Grid. How well technology is applied to fulfilling that requirement could have a significant impact on just how smart the Smart Grid ultimately will prove to be.
The power grid is obviously a critical national infrastructure. Our economic and social fabrics (to say nothing of our wireless networks) are severely strained when the lights go out, which unfortunately happens far too often with our current, obsolete grid.
Additionally, the whole topic of energy generation and usage is of vital interest right now because of concerns about global warming. The grid is smack in the middle of this issue in at least three ways. First, coalfired power plants, the dominant means of electric power generation in America, are a leading contributor of greenhouse gasses. Second, it is anticipated that over the next couple of decades, much of the energy for transportation will shift from fossil fuels to electric power. And third, the current grid is less efficient than it could be, so a lot of the power being generated is wasted in delivery.
The Smart Grid will address these deficiencies in a number of ways, beginning with power generation. Alternative energy sources such as wind and solar will likely take on more of the load. And while controversial, new nuclear power plants may be added to the mix. In most cases, these new generation facilities will need to be located well away from large cities where most of their output will be consumed. What’s more, wind and solar power sources are by their nature geographically distributed. So, the Smart Grid will need to transport power over greater distances with more efficiency and with higher reliability. To do this, generating and transportation facilities will have to be highly integrated and automated, with electronic controls and many thousands of devices, such as power condition sensors, communicating with each other.
THROUGHPUT, LATENCY & RELIABILITY
There are a number of interesting aspects of this communications piece. It will mainly be machine-to-machine (M2M), and for the most part will require relatively low data throughput. However, because some of it provides feedback for automated control, latency may be a major concern. It will almost certainly be carried on private data networks since the utilities are not likely to depend on the public Internet for data communications critical to grid operations. For the same reason, the private networks involved will have be extremely reliable.
Wireless is expected to play a major role in data communications for the automated Smart Grid, as a quick and cost-effective way to connect thousands of widely distributed electronic devices and to provide redundancy for fiber and copper connections.
Wireless data communications also will be vital to the Smart Grid at the local power distribution level. There, the vital issue is peak load management. For example, on hot days in Los Angeles, the use of air conditioning equipment in residential and commercial buildings often taxes the capability of the local utility to meet peak demand. The situation is likely to get worse in coming years as people start plugging in their electric cars for a quick battery recharge. Unfortunately, a distribution system built to accommodate extreme worst-case peak loads tends to be relatively inefficient on average.
There are several ways to address this problem. The simplest is probably through charging the consumer a premium for power used during peak load periods. This requires a "smart meter that records and reports usage within specified time periods. More complex load management techniques involve micro-management of the interruptible services, such as air conditioners, in individual premises so as to balance peak loads as required. For practical operation, each of these load management systems will require M2M data communications between the local power distribution system and individual customer premises. Wireless is the obvious means to provide the required connectivity.
CHECK THE SPECTRUM
So, between generation, transmission and local distribution, wireless M2M data communications will be vital to the Smart Grid, but what technologies should be used, and on what spectrum? There are any number of possibilities, including several proprietary approaches being peddled by companies eager to capture a huge new market. Some of these involve use of unlicensed spectrum, particularly for neighborhood communications with "smart meters. But utilities are, or at least should be, leery of potential problems with using unlicensed spectrum for critical data communications, and they should be particularly cautious about adopting proprietary (as opposed to open standards) solutions.
Utilities are also dubious about the idea of contracting with commercial wireless data network operators for Smart Grid communications. Part of this stems from their traditional insistence on managing all aspects of the grid and part of it stems from the need for higher reliability than existing commercial networks can offer.
Citing a need to build private data networks for the Smart Grid, the Utilities Telecom Council, an industry organization that lobbies on behalf of utilities' communications interests, has recently petitioned the FCC to allocate 30 MHz of spectrum in the 1800 MHz band. But even if the FCC were to approve this request, the cost of such networks built with the required coverage ubiquity and reliability could be daunting. As an alternative, I have proposed that the Smart Grid share a 700 MHz "Critical Infrastructure Network with public safety users. (See "CIN 3 in 1 Wireless Week June 1, 2009.)
To meet its future promise, the Smart Grid will need to be plenty smart. Wireless data communications will play a vital role, so utilities should be equally smart in making decisions about which technologies and networks to use.
Drucker is president of Drucker Associates. He may be contacted at edrucker@druckerassociates. com.