The roll-out of smart meters is happening between 2012 and 2020

Smart meters collect and record information about the electricity and gas you use in your home. The data can be really useful to you when working out how much energy you use, and finding ways to save money. But how much does this data give away about you?

At Which? we think that there should be protections in place to limit the information your energy supplier can gather. And we think that you should be kept fully informed about what is being collected, how it is used and who it is passed to, and how you can control all of these aspects.

Alongside our smart meter challenge, we're also challenging energy companies to be up front about your data. When your supplier comes round to install your smart meter, we think they should let you know exactly what information they'll be collecting, so you can make informed choices. 

What data is collected?

Smart meters will allow your utility company to take regular meter readings and (for pre-payment customers) details about payment.

On the surface this sounds like a good idea. After all – companies know how much gas and electricity you use anyway. But we're concerned that your energy company could be taking far more information than they really need. By taking very regular meter readings, your utility supplier could know far more about you than you want them to.

By reading your meter every 30 minutes, your utility company could build a pretty detailed picture about your life. They can establish your working patterns - when you are in or out, make a good estimate of how many people live in your household, how you tend to use your appliances, and when you go on holiday.

Why is the data controversial?

Use of personal data

The information collected from smart meters could be really useful to you personally. It could help you make choices about how you use energy and could help you lower your energy consumption and costs.

However, if you have not been given the choice about whether you want to provide this data to your utility company, it could be used in ways that you're not comfortable with.

Companies could use it for marketing purposes, or pass it to other companies who want to sell you products and services.

If you regularly go away on holiday or for work, your information is valuable to companies who might want to sell you burglar alarms, secure double glazing, or travel insurance. If your heating is always on you could be in the market for a new boiler.

Security of personal data

The government have been clear that protection of customers' data is very important, but consumers need to see exactly how they plan to deal with this issue.

Many privacy groups have raised concerns over the security of the data collected. As it is being transmitted wirelessly there is an opportunity for people to intercept the data as it is transmitted back to the utility company.

The more frequently the data is passed from your meter the more opportunities there are for people to intercept it. At the moment smart meters transmit data once every 30 minutes, far more frequently than the readings taken if you have a 'dumb' meter – usually once every couple of years. Does your energy company really need a reading every half-hour just so they can give you an accurate monthly bill?

Some say yes – the 30 minute readings allow companies to offer 'time of use' tariffs. These give consumers cheaper energy at certain times of the day. However not all customers will be on this kind of tariff, so we'd like to see everyone informed about how often readings are taken, and offered the option to have readings taken less frequently if it isn't necessary for their account.

What Which? wants

We're all for smart meters – they'll make taking energy readings much easier, make your bills more accurate, and give you better information about how you're using energy. But we want to make sure that consumers are kept fully informed about what companies are doing with their data, and have the option to control the amount that is collected, what it is used for and who it is passed to.

Here are our recommendations:

• The data collected through your smart meter is classed as 'personal data'. This means that it is covered by Data Protection legislation, and there are security standards which must be met, as well as strict rules on how the data can be used and retained by companies. The companies dealing with smart data need to be policed to ensure that they comply with this – and there needs to be enforcement when they're not.
• Consumers should be given clear indication of what data will be collected and how it will be used. Any data collection that is above and beyond what is required to put a monthly bill together should require the consumer's consent.
• Consumers must ultimately own their own smart data and be permitted easy access to it. They should also be allowed to transfer this to other service providers if they want to, making it easier for them to switch.
• Meter readings should be taken at reasonable time intervals, chosen by the customer. This would prevent utility companies from establishing personal information, such as work patterns and when you are away on holiday, without your consent.

We're currently calling for the government to stop and review the smart meter roll-out, as the roll-out is being led by the energy companies with no checks in place to make sure that costs don't spiral.