Types of Electricity Meters
There are many styles and models of electric meters, we’re all close to one but rarely think about it. When I’ve asked around most people can at least say it’s round and what side of the house it is on. As renewable self generation becomes more popular these meters will continue to be upgraded and become more advanced to support utility operations.
The two primary generations of meters can be broken down into:
1) Mechanical Meter
2) Digital Meter
Mechanical or dial type electric meters are still very common and have been in service for many many many years. This style meter is typically read monthly by a person, usually a full time meter reader, that is walking past the meter in small towns. In some cases for larger territories the meter values are self reported with a phone call once a year. Many are being upgraded to newer meters, however there are still a lot of meters out there!
The newer style Digital electric meters have wireless communication that allows the utility to read the meter and receive notifications remotely. The two primary types of readings are called AMR and AMI, I’ll cover those more below. The Digital meters typically support more data.
Mechanical Electric Meter - made by Elster - Glass cap is typically more rounded and more of the mechanics are shown. Typically all metal stamped information.
Digital Meters
Advanced Meter Reading (AMR) - Drive-by or Touch-pad Meters
Advanced Meter Reading (AMR) involves installing a digital meter that can broadcast its data occasionally and at short range. Typically used in electric, gas, and water metering. Original versions required close proximity (4-10 feet) and offered the easy logging of the readings. Newer and more common are now drive-by readings. The meter broadcasts its readings, alarms, and status regularly so that as the driver is a street or two over they will pickup the monthly reading on their route.
Advanced Metering Infrastructure (AMI) - Networked Meters
Advanced Metering Infrastructure (AMI) is an integrated system of smart meters, communication networks, and a data management system. This includes installing a smarter digital meters that typically support two-way communication. These two-way smart meters allow the utility to gather more regular usage data and support more advanced rate programs.
Internet-of-Things (IoT) and Smart City technology has been improving the AMI networks by opening up the communication networks layer to more open and standard protocols. IoT technology like LoRaWAN supported by the LoRa Alliance is disrupting the space quickly as it proves to be the only Utility owned infrastructure model that has the potential to be interoperable. This is in comparison to the typical AMI system that is deployed with the “Apple” model, meaning vertically stacked one vendor solution and only interoperates (well) with itself. These are typically called “Mesh Networks” and require data to “hop” across multiple meters to the main communication network.
In summary, Mechanical meters - one to one readings; Digital AMR meters - one to a few readings; Digital AMI meters - one to many.
Digital Electric Meter with Energy Delivered value of 1144kWh. Plastic / PVC hard cover with UV resistant label including meter and utility information.
Types of Data from Meters
In both Mechanical and Digital meters the primary "reading” is the total energy delivered. Energy delivered is measured in kilowatt-hours (kWh). This is the value shown on the face of most meters, it is typically a long number that is read and then compared to the last reading.
Example: April reading 1135 and May reading is 1445; meaning the total monthly bill will be for 1110 kWh.
Digital meters then enable more data, including access to: Voltage, Frequency, Tamper Status, Demand Peak, different Rate Profiles, and much more diagnostic data on the device itself.
Meter Shapes and Mounting (aka. Form Factors)
Two primary categories of meter types, the most common is Socket Mount (shown above) this is the typical shape and comes in a variety of configuration for the site. The alternative found mostly in commercial buildings are Panel Mount meters