While smart meters can be limited to just reporting the entire household electricity use, and thus don't need to gather information from appliance use inside the home, people should be aware that the goal of AMI is to monitor electricity use of every appliance inside your home, and possibly control it.
To quote a US Department of Energy document on AMI, it's defined as "This infrastructure includes home network systems, including communicating thermostats and other in-home controls, smart meters, communication networks from the meters to local data concentrators, back-haul communications networks to corporate data centers, meter data management systems (MDMS) and, finally, data integration into existing and new software application platforms." See page 5 of http://www.netl.doe.gov/smartgrid/referenceshelf/whitepapers/AMI%20White%20paper%20final%20021108%20%282%29%20APPROVED_2008_02_12.pdf .
Not only that, the electric utility industry is currently exploring the use of "big data" techniques to collect and sort through all the data gathered from customers' homes. One upcoming conference for the utility industry on big data techniques is described at http://utilityanalyticsweek.com/details#1AdvancedAnalytics . In its most benign form, your electric utility might constantly nag you that your refrigerator uses too much power and should be replaced or you leave too many lights on, but in a full AMI implementation they will have the capability of actually shutting down appliances in your home remotely.
As another piece of evidence, I live in Boulder, CO, which was supposed to be the first "Smart Grid" city in the nation as part of a demo project installed by the utility Xcel. The first thing they did was install smart meters and a fiber optic network reaching every customer home and business in Boulder. I wondered at the time why they needed the huge bandwidth of fiber; now I know. Fortunately, the costs overruns of installing fiber in the city killed the project (originally priced at $15 million, it went to $45 million).
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A Smart Grid Can't Beat "V=IR"
Edited by Carlos Zavala
Updated - 12th Sep
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A Smart Grid Can't Beat "V=IR"
Edited by Carlos Zavala
Updated - 12th Sep
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AMI will monitor every aspect of your energy usage
Posted by zackers
Updated - 10th Sep
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A Smart Grid Can't Beat "V=IR"
The term "smart grid" is tossed around like salad. It is advertised as the panacea for the country's energy woes. But it is not that simple.
A coal fired power plant is about 50% efficient at turning the energy in coal into electricity.
A nuclear plant - essentially the same thing as a coal plant, a giant water boiler running steam through turbines - operates about 5% less efficiently at 45% efficient because of they operate at slightly lower temperatures for improved safety.
Both of these types of power plants are usually located far away form population centers and the distance the electricity has to travel significantly cuts the overall efficiency "at the plug". Fifty % of 50% is 25%.
A combined cycle gas turbine engine system produces electricity at about 65% efficiency and can be located far closer to population centers, but these are relatively new and expensive. Most electricity produced locally runs at under 20% efficiency because of the age of the equipment and the high capital cost to replace it. This type of generation is usually used during power shortages.
Overall a conservative estimate of the efficiency of electricity delivered to the plug is 25%.
Utility companies have schemes to switch people to electric cars claiming they will "save energy" but what is not advertised is the overall efficiency of the grid at the plug, the fact that there are losses in converting the electricity to chemically stored energy in the battery, and then losses when that stored electricity is converted back to electricity to run the car. Hybrids, storing energy both chemically and electrically should be far more preferable to educated consumers than straight electric vehicles.
What is also not advertised is that the electric companies would like to have your car discharge much of the night to power their grid, and then they'll recharge you quickly before you get up to go to work. And this is the real value of a smart grid for them. If they can figure out when you will really drive your electric car, they can pull off this increased cycling of your battery, benefiting them and benefiting car companies that will supply consumers with new batteries more often. If they can't predict when you'll need your car, they can't really do this.Of course, consumers should be concerned that they might need their car at odd times, such as for a trip to the emergency room.
The smart metering that goes along with the smart grid does give utilities another window into your life. They can characterize the energy profile of every appliance in your home and know what you are using when - that is assuming they already can't since almost everything is connected to a network lately including the camera staring you in the face that's connected to your computer.
What is more of an issue with the smart grid is that with the stroke of a politician's pen, utilities will begin to charge customers on a Time-Of-Use basis like they do commercial and industrial customers. If you're working a 9-5 job, not really a big deal that you set your thermostat to 82 degrees during the day. but if you have young children or old relatives who are at home all day, or if you just lost your job, under a TOU system, you might get charged an electric bill that is 2 or 3 times what it is under today's residential electric rates.
Back to V=IR, at high electric usage, no matter how much electricity they pump in, the demand is sucking enough to drop the overall grid voltage. The appliances in your homes, businesses and factories pretty much maintain a constant "R" resistance. That means that as grid voltage drops, current (I) increases. Things don't burn-up just because of high voltage or resistance - but from high current. The increasing current in your appliances causes the insides to go poof, letting the smoke out. It also makes the wires between you and the power plant get hotter and go poof too. A smart grid won't help this problem because this is simply a matter of the physics of the wires.
A coal fired power plant is about 50% efficient at turning the energy in coal into electricity.
A nuclear plant - essentially the same thing as a coal plant, a giant water boiler running steam through turbines - operates about 5% less efficiently at 45% efficient because of they operate at slightly lower temperatures for improved safety.
Both of these types of power plants are usually located far away form population centers and the distance the electricity has to travel significantly cuts the overall efficiency "at the plug". Fifty % of 50% is 25%.
A combined cycle gas turbine engine system produces electricity at about 65% efficiency and can be located far closer to population centers, but these are relatively new and expensive. Most electricity produced locally runs at under 20% efficiency because of the age of the equipment and the high capital cost to replace it. This type of generation is usually used during power shortages.
Overall a conservative estimate of the efficiency of electricity delivered to the plug is 25%.
Utility companies have schemes to switch people to electric cars claiming they will "save energy" but what is not advertised is the overall efficiency of the grid at the plug, the fact that there are losses in converting the electricity to chemically stored energy in the battery, and then losses when that stored electricity is converted back to electricity to run the car. Hybrids, storing energy both chemically and electrically should be far more preferable to educated consumers than straight electric vehicles.
What is also not advertised is that the electric companies would like to have your car discharge much of the night to power their grid, and then they'll recharge you quickly before you get up to go to work. And this is the real value of a smart grid for them. If they can figure out when you will really drive your electric car, they can pull off this increased cycling of your battery, benefiting them and benefiting car companies that will supply consumers with new batteries more often. If they can't predict when you'll need your car, they can't really do this.Of course, consumers should be concerned that they might need their car at odd times, such as for a trip to the emergency room.
The smart metering that goes along with the smart grid does give utilities another window into your life. They can characterize the energy profile of every appliance in your home and know what you are using when - that is assuming they already can't since almost everything is connected to a network lately including the camera staring you in the face that's connected to your computer.
What is more of an issue with the smart grid is that with the stroke of a politician's pen, utilities will begin to charge customers on a Time-Of-Use basis like they do commercial and industrial customers. If you're working a 9-5 job, not really a big deal that you set your thermostat to 82 degrees during the day. but if you have young children or old relatives who are at home all day, or if you just lost your job, under a TOU system, you might get charged an electric bill that is 2 or 3 times what it is under today's residential electric rates.
Back to V=IR, at high electric usage, no matter how much electricity they pump in, the demand is sucking enough to drop the overall grid voltage. The appliances in your homes, businesses and factories pretty much maintain a constant "R" resistance. That means that as grid voltage drops, current (I) increases. Things don't burn-up just because of high voltage or resistance - but from high current. The increasing current in your appliances causes the insides to go poof, letting the smoke out. It also makes the wires between you and the power plant get hotter and go poof too. A smart grid won't help this problem because this is simply a matter of the physics of the wires.
Posted by Carlos Zavala
Updated - 12th Sep