Energy adviceSettlement consent

Consent to use consumption data for Settlement

Questions and answers: half-hourly settlement

Market-wide half-hourly settlement is a new system introduced by Ofgem to improve how energy suppliers in the UK buy and sell electricity. 

It aims to modernise the energy market by improving how electricity is measured, priced, and settled. 

It’ll play a big part in helping the UK switch to cleaner energy. And help create a more efficient and improved electricity system, a big step toward net zero.

How will the half-hourly settlement work?

The half-hourly settlement will allow suppliers like OVO to access usage data every 30 minutes.

Currently, Smart electricity data for settlement is based only on monthly readings. This allows suppliers to see how much energy has been used but not when used. 

Moving towards half-hourly settlement will help suppliers forecast the energy customers need more accurately. And buy electricity to meet that need in advance. 

As a result, they’ll only buy the necessary amount of electricity for their customers. And encourage customers to shift usage to cheaper times of the day.

This will help stabilise the grid, reduce carbon impact, and ultimately lower the cost of energy for UK consumers. Better forecasting will allow purchases from renewable sources rather than expensive, carbon-heavy generators. 

What is the settlement process?  

BSC (Balancing & Settlement Code) compares the amount of electricity we’ve bought as a business with the amount used by our customers. Any difference is then charged or refunded to us.

Using estimated data means Suppliers often under or over purchase electricity. To cover any imbalance, the BSC charges or pays us their default rates, which are usually to OVO's (and therefore the customer's) financial dis-benefit. This is called the settlement process. The more accurate our customers' consumption data is, the better our trading team can ensure that they get the best possible price.

Currently, this process only happens daily. However, the new system can also take place every 30 minutes, known as a half-hourly settlement.

We’ll only collect half-hourly data from smart meters if the customer allows it (or if it’s required). Traditional meters won’t be affected.

What are the benefits of a half-hourly settlement? 

Some of the key benefits include:

  • Help make sure our electricity system is fit for the future

  • Create a fairer and more accurate settlement process 

  • Help the UK rely more on renewable energy

The half-hourly settlement will pave the way for future innovative energy products and services. Which will help customers better understand their energy use to save money and carbon.

Overall, it’ll be crucial in helping the electricity grid reach net zero by 2035. And plays a huge role in taking the UK towards net zero by 2050.

How do energy suppliers like OVO buy electricity?  

OVO offers fixed-rate plans where you pay a set price per kilowatt-hour (kWh) of electricity used. To guarantee this price, we buy electricity in advance from  electricity generators.

We look at general demand patterns to predict how much electricity our customers will use at different times of the day. 

The half-hourly settlement will help us forecast the energy our customers need more accurately. This means we can buy electricity at a lower price in advance. It will also mean that suppliers are more likely to offer time of use tariffs that encourage customers to shift consumption to outside of busy times of day for the grid.

Why does the cost of buying electricity change? 

The cost of electricity is constantly changing and varies every 30 minutes.

When ‌electricity demand is low we can rely on cheaper, renewable sources like wind and sun to power the grid.

However, renewable energy has its limitations. It doesn't go as far when the electricity demand is high, like during during peak hours on an evening.

As a result, the electricity grid has to rely on more expensive, carbon-heavy fossil fuels to fill the gap.

When will the half-hourly settlement start? 

In 2024, energy suppliers will start to collect half-hourly readings from smart meters if the customer allows it (or if it’s required).

In 2025, suppliers will begin to use this data for settlement purposes.

Will the changes affect me?  

If you have a smart (or Advanced) meter, whether it impacts you will depend on your energy tariff. Let’s take a look:

Time-of-use tariffs 

If you’re on a time-of-use tariff, like Economy 7 or Economy 10, your smart meter will automatically send half-hourly readings. 

You won’t be able to opt out because the product or tariff needs this data for billing.

Export tariffs 

If you’re an export customer, like solar generation (where we buy the energy you generate), your smart meter will automatically opt-in to send half-hourly readings. 

You won’t be able to opt out because your payment is based on your generation, measured half-hourly.

All other tariffs

The changes won’t affect you unless you’re going through a ’change event’, like starting a new contract. Let’s look each event: 

Will my smart meter default to half-hourly?Can I opt out of half-hourly?
Changing contractsYesYes - depending on your tariff, you could choose to opt out to daily readings 
Have recently joined OVOYesYes - depending on your tariff, you could choose to opt out to daily readings 
Selecting a new tariffYesYes – depending on your tariff, you could choose to opt out to daily readings 
Installing a smart meterYesYes – depending on your tariff, you could choose to opt out to daily readings 
Changing to Pay Monthly (PAYM)YesYes – depending on your tariff, you could choose to opt out to daily readings
Changing to Pay as you Go (PAYG)YesNo
End of contract (i.e. end of a fixed term)* NoNA

*If you’ve come to the end of your contract and choose a new tariff/contract, we’ll collect your consent to use your half-hourly consumption data for Settlement as part of that journey. If you take no action (meaning you roll onto our Standard Variable Tariff, we won’t default you to half-hourly readings).

For more information, please see our privacy policy.

How can I manage my meter settings? 

You can log into your account or call us on 0330 303 5063 to manage your meter reading settings for billing and settlement. 

If you’re waiting for a smart meter, you can change how often we collect this data after installation.

How do smart meters help the settlement process? 

Smart meters can send electricity usage data every 30 minutes. Energy suppliers like OVO can use this data during the settlement process. 

Smart meters are also a great way to see how your home uses energy. They give you more control of your energy use and help you spot ways to save.

Don’t have a smart meter? Book an appointment, and we’ll install one for you for free.

How will OVO protect my data?

The data used for settlement is combined and anonymised to ensure individual customer privacy.

We’ll always keep your data safe and won’t use it for other purposes without your permission. For more details, please see our privacy policy.

Find out more

To learn more about half-hourly settlement, please visit Ofgem's website.

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