Smart meters are advanced electricity meters offering capabilities and services beyond traditional accumulation and interval meters.
They can provide real-time data on energy consumption, enable flexible pricing tariffs, transmit energy use data to utilities, receive and carry out commands, monitor the supply for faults, act as a communication point for important information, and interface with appliances via a home energy network.
Smart meters are being adopted by utilities and governments worldwide, but their adoption and use vary. For example, in Australia, different states and utilities have different policies on smart meters, with some offering more advanced capabilities than others.
The various meter box technologies explained
The traditional electricity meter, or accumulation meter, only records the amount of electricity that has passed through it since it was first installed or last reset by the utility. All you can tell about your electricity use with an accumulation meter is how much energy you have used since the previous reading. It does not give you much insight into consumer behaviour.
Electricity billing is based on the differences between successive readings. Traditionally, meter readers went from house to house every 2 or 3 months. To then record the numbers on each meter. Most gas and water meters, along with old-style accumulation electricity and gas meters in the field, still use this reading method.
A house with an off-peak water heater usually has two accumulation meters — one for the water heater and one for everything else, such as power, lighting, air conditioning, etc. The meters with the spinning disk are a typical version of a traditional accumulating electricity meter. Overall not too smart, as they do not allow any sophisticated demand-driven billing. A majority of Australian homes in established areas still have these meters.
Digital interval meter
Basic digital electricity meters, also called interval meters, measure energy electronically. They are a little smarter than the accumulation meter, and they record energy use at half-hourly or even shorter intervals. They usually have a digital display and can download the data to the meter reader via an electronic or optical interface.
The main difference from the accumulation meter is that they can support “time of use tariffs”. Under this, the customer pays different rates for electricity used at different times. In some areas, time of day, metering and charging are being implemented to give customers financial incentives. Their flexible appliances can then use this when there is a lower demand on the grid.
Flexible appliances, as the name can be used flexibly, unlike a fridge. Which needs to run 24/7, including the dishwasher, washing machine, pool pump, and vacuum cleaner. While digital, these meters are not generally considered smart as they do not send the data out. So a person still has to come past to collect the data.
Smart meters, also called advanced metering infrastructure (AMI), offer capabilities and services that accumulation and interval meters do not. While the local energy utilities do not always enable these capabilities, smart meters can, in general:
- Provide real-time data to the householder on how much electricity they are consuming. Consumers seldom receive the option to access it through a web portal or an ‘in-home display’.
- Enable the option of flexible electricity pricing tariffs;
- Transmit energy use data to the utility so that meter readers are no longer required. Usually via the web, once a day – not in real-time;
- Receive and carry out commands. Such as disconnecting the supply when customers move out;
- Monitor the supply for faults and automatically advise the utility in case of problems;
- Act as a ‘gateway’ or point of communication to the home for important information. Such as changes in price or notification of emergencies;
- Act as a 2-way interface with the customer’s appliances via a ‘home energy network’.
They installed over 1 million units specifically in Victorian homes as part of a new metering initiative. While a positive initiative to upgrade meter reading hardware and billing options. The time of day metering has not been positive in many communities.
How electricity suppliers and their customers use these capabilities varies and is likely to change over time.
In Australia, different states and electricity utilities have other policies on smart meters.
Some smart meter models can be configured to measure the renewable energy generated by a photovoltaic solar system and to show how much electricity has been exported to the grid. As well as how much has been consumed on site.
Intelligent metering options
Sophisticated solar monitoring systems, such as solar analytics, can directly connect to the smart meter and get data regularly to give the end customer a wide range of solar and battery monitoring information.
It can also meter the consumption and generation via its separate hardware and distribute this data in 5-second live intervals. This type of live monitoring is smart metering, as one can see what appliances are doing, and therefore the homeowner can better optimise their energy use.
Certain States and Territories run dedicated replacement programs for old meters with smart ones, while in other areas, they only install them during meter replacements.