What is Smart Meter Technology

Smart Meters Includes:
Smart meter technology     Circuit design    

Smart meters are being introduced for many utility supplies in many countries. As consumers and customers will already have meters installed, the roll out is gradual, but it is steady and occurring in many countries.

Smart energy meters can be used for utilities like electricity, gas and even water - for utilities and supplies that need to be connected and metered.

The smart meters allow utility companies to monitor usage remotely without the need for meter readers to visit, or for customers to provide readings, and they can also give insights into usage so that the utility networks can be run more efficiently. This is a major advantage when all countries are trying to reduce their environmental impact.

One key aspect is the electricity usage data provided enables the smart grid to be put into place that will deliver energy more efficiently with less ecological impact.

What is a Smart Meter

A smart meter is essentially a utility meter that is able to communicate with the supplier to enable meter readings to be taken remotely as well as monitoring the daily usage performance of the whole network in a more understandable fashion.

In addition to this the smart energy meter normally provides details of the current and past history of consumption to the users. This enables the user to monitor and adjust their consumption, giving a better possibility of being able to reduce consumption and thereby become more economical in the use of the electricity, gas, water, etc.

There is a considerable variation in the possibilities for smart meter designs. Often countries or regions may adopt their own standard for the format for smart meters as this enables the meters to be tailored to the requirements of that region, their communications system and the like. Having a common standard can also help where there are several different energy suppliers and consumers may want to swap between them. As installing a smart meter requires the energy supply to be disconnected and a new meter installed in line, the installation can be costly, on top of the cost of the meter.

Also there is a difference between smart meters used for electricity and those used for gas or water, etc as power can be an issue.

Electricity smart meter

Essentially a meter consists of the sensor to detect and measure the electrical energy consumption. This needs to be processed and the data suitably formatted. This then needs to be communicated to the supplier and normally to the users as well so that they can monitor and adapt their usage accordingly.

In terms of its functionality the main blocks are shown in the diagram above.

Like the older manual meters, smart meters still need a very accurate measurement of the usage of the electricity. This needs to be converted to a digital format where it is then passed to a processor.

The processor section formats the data, and will normally display it on the smart meter itself. It also passes the data in a suitable format into the radio communications section.

The radio communications section of the smart meter will communicate with the utility provider so that consumption can be monitored on a regular basis. A number of communications technologies can be used for this including power line, cellular (often 2G GSM), LoRa and others.

Typically the system provides two way communication to enable meters to be interrogated as required.

A consumer monitor often called a smart energy monitor or In Home Display, IHD is also often provided and a short range wireless communications technology is used for this. Again there are a variety of systems that can be used. These smart energy monitors or in home displays provide a useful insight into usage providing information about monthly usage, weekly usage, daily usage and current consumption. This helps the user manage the use of energy more appropriately.

The electricity smart meter is able to draw a very small amount of electricity from the line supply to power the smart meter enabling it to communicate with the user display and also the utility supplier.

Gas and water smart meters

Unlike smart meters used for measuring electricity consumption, gas and water meters cannot draw electrical power from their supply to drive their electronic circuitry. Instead they seek electrical power from another source.

To power any internal circuitry, they often use a long life battery, and use very low consumption electronic circuits for the measurement. data is often transmitted over a low power link, and periodically to minimise the power consumption.

As gas and electricity are often supplied by the same company in many countries, the gas smart energy meter can be paired with the electricity one - a short range link transmits data, possible every half hour or less from the gas meter to the electricity meter which has access to power. This electricity smart meter then acts as the hub communicating electricity and gas information to the utility provider and to the user smart energy monitor.

Battery lifetime is key as it requires a field replacement of the battery by a qualified engineer. Battery lifetimes of ten years are frequently quoted.

Obviously other schemes can be used if the gas or water smart meter is not co-located with an electricity one, and various schemes are available to overcome these issues.

Smart meter benefits

The use of smart meters bring many benefits to users, to the utility providers for automated meter readings and also to the overall grid management, load forecasting and the like.

Each group sees different benefits.

Utility users:

• Automated utility meter readings - no need for meter readers or user supplied data
• Accurate readings can be provided regularly for more accurate billing

Utility provider:

• Reduce costs by having readings provided remotely - no meter readers required
• Reliable regular regular readings can be taken
• Usage characteristics can be determined so that more accurate provision can be made

National provision planning:

• More granular data can be obtained to understand user requirements better
• Better data to enable long term usage for different sections of users - understand time for usage of different groups, trends, etc.

The installation of smart energy meters has benefitted users and providers alike giving more accurate and more regular data to be able to give accurate bills as well as regular data that will enable a better service to be maintained. For the users, live data gives a better understand of the usage and this can help to reduce consumption and give more ecological / green usage.

It is hoped that the use of smart meters will entice users to manage their consumption better, reducing usage and thereby helping to fight climate change better. It is just one of many tools that will help.

  Written by Ian Poole .
  Experienced electronics engineer and author.

More Eco / Green Engineering Topics:
Smart meter technology     Solar electricity generation     Smart grid     Home energy saving technology     LED lights     Energy saving guidelines    

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