Older meters have dials on them to record power usage. As technology advances, many of them have been replaced by "smart meters". Let's take a look at how they work.

Smart meters can provide data to users in real time so that they can turn off some appliances to save electricity.

Some of the more advanced smart meters can be preset or controlled via the internet to turn on certain appliances, such as air conditioners, at different times.

In some countries, the cost of electricity during the day is different to that at night, so it can be cheaper to use some appliances (such as the washing machine) or to charge an electric vehicle when the rates are lower.

More advanced systems can even send the electricity generated from solar panels or windmills back to the power grid, and sell the extra electricity back to the power companies.

With the installation of these smart meters, power companies can retrieve the usage data immediately, and can decide right away how many generators will be needed to provide enough power and thus save cost.

In addition, should a transformer break down, power companies can switch the electricity supply from other areas to the affected area, and make sure people are without power for as short a time as possible.

Although smart meters can bring advantages to both customers and power companies, they are still not used in many countries. The main reason is that power companies can obtain information on customers' lifestyles (such as the time when they are home and the time they go to sleep) based on the pattern of their electricity usage. Some people might say that's an invasion of privacy. Some customers, therefore, would refuse to install such meters because even if they can save money on electricity usage, they might be giving up too much of their privacy. That is something that should be considered if smart meters are to be introduced in Hong Kong on a large scale.

Why is the use of smart meters still not widespread in many countries despite its various advantages?

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