Discovery Guides Areas


Plugging Into the Future: Smart Grids
(Released November 2009)

podcast link 
  by Marianne Stanczak  


Key Citations




Back to the Smart Grid


More an energy concept than a tangible structure, the smart grid is an electronic means of transmitting and distributing electricity, where both utility companies and consumers will have the ability to interact with each other and regulate the amount of electricity used. Where the current system has been compared to a one-way street, the smart grid is touted as a transparent or two-way line of communication from power source to customers and back again.

Perhaps the most fundamental aspect of transitioning to a smarter electricity system is the smart meter.
meter closeup
A Smart Meter
If you take a look at your current electricity meter, you will see that it is very mechanical, humming along blindly, waiting to be read by a technician (or —gasp! —estimated), to determine the amount of electricity used in a given month, at the end of which you receive a bill. Very straightforward. Also not very transparent. Other than shutting off electricity-using devices, you as the consumer currently have no way of controlling your electric bill. A smart meter utilizes what is known as real-time monitoring (RTM). A display lets the consumer know how much electricity is used and even when it is less expensive to use it. In essence, a message can be sent to the consumer (in the home or via cell phone or email) that alerts them of a better time to use a certain appliance. Like the stock market and certain cell phone plans, electricity has daily ups and downs; it is not one flat rate through the entire day. However, the consumer is currently being billed as if there were one flat rate. In contrast, a smart meter will let customers know when it is cheapest to use electricity, so they may hold off using non-essential appliances such as dishwashers, clothes washers and dryers until later in the day, a "non-peak" time. Not only does this RTM save homeowners money, it allows them more control over their overall electricity usage. Many people currently have programmable thermostats, for example, used to keep temperature at a level preferable to the homeowner and lessen heating and cooling when not at home. The smart meter acts in a similar way, just on a broader scale; with the smart meter you can control —and even program, in some cases —several appliances. In addition, demand response, wherein consumers base energy usage on non-peak demand, may even serve to give back to the consumers, as a credit on an electricity bill. Demand response is simply the response a consumer has (e.g., holding off running the dishwasher) to the level of demand. Mid-afternoon is the normal peak demand for power, so the response would be to run the dishwasher later in the evening. Real-time monitoring and demand response work together to benefit the consumer.

"Studies have shown that when people are made aware of how much power they are using, they reduce their use by about 7%."2
computer device
Device to monitor power grid and turn appliances off for a few seconds or minutes in response to overload. Developed by Pacific Northwest National Laboratory.
Smart meters are part of a larger concept known as advanced metering infrastructure, or AMI. The smart meter acts as a sort of middle man between the customer, utility company and original power source. A sort of back-and-forth goes on in AMI, where sophisticated devices such as smart meters and software are constantly monitoring the voltage and current for electricity, not only to assess what is peak demand, but to allow power companies to monitor the power grid itself. This is done by items called synchrophasors, which measure current and voltage in various places on the electric grid simultaneously. Synchrophasors collect this data 30 times a second, as compared old methods that collected data once every 4 seconds. In turn this "real-time" data may be used by a utility company to keep track of its power usage as well as to adjust levels so less energy is wasted.

So this sounds pretty good for you as the consumer, but what about the utility companies —what makes them want to get involved with the smart grid? On a very basic level, utilities will be able to profit from installation of smart meters, which currently cost around $125 each. And like consumers, utilities can benefit from demand response and RTM. Because the consumers are using less power during peak demand times, lessening the load on the power grid, the flow of electricity is more efficient and there is less need to put up new poles or even to build new power plants. A smart grid also prevents the entire system from becoming overloaded, lessening the chance for a power outage.

In addition, a process called distributed automation would allow power companies to operate more remotely. This would allow them to fix outages or other problems remotely rather than sending a technician, thereby saving money and getting the job done faster. Distributed automation also allows a company to switch power usage —if it notices that a certain area is not using a lot of electricity, power can be "moved" to an area that does. If a system is working inefficiently there can be a bottleneck of electricity that, if not relieved, can cause an overload. In distributed automation, the system remotely monitors power distribution, and if it sees such a bottleneck an alarm or alert is sent out and the electricity can be rerouted by the opening or closing of a switch or circuit breaker. This rerouting may be done by a human, or the computer system could reroute automatically based on a predetermined "danger" level.

Another important factor from the utility point of view is that, with a smarter, more transparent electronic system, if a transformer is in danger of "blowing," the power company can quickly assess the situation and act accordingly, a process known as event avoidance. As well as averting the need to send technicians to an outage site, the transparency allows companies to pinpoint a problem's location rather than having to wait until many people call to report an outage.

If this is not the end of blackouts, at the very least they will be much shorter-lived. In addition to possible event avoidance, a preemptive strike, if you will, the smart grid can restore power, which currently is done manually. This automatic restoration of power would be accomplished by a combination of sensors, computer analysis and advanced substation components, as well as by the ability to reroute power to outage locations.

Another component to the smart grid would be the replacement of the aging power lines (with the tendency toward sag) with high-temperature superconducting lines. These wires, in addition to withstanding higher temperatures than the current wires would also help utilities by delaying installation of power plants, or even by doing without them all together. And, the new wires could be installed underground to avoid cluttering up the already congested cityscapes.

So we have a more transparent, reliable system that allows consumers to save money and utility companies to more accurately control electricity. A win-win situation.

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