Page last updated on 17th August 2026
Energy flexibility: what is peak and off-peak energy?
This guide explains what are the peak and off peak times for electricity, how off peak energy tariffs work and how smart meters can help households access more flexible energy pricing.
You might have heard of energy-saving schemes that offer rewards for demand-side flexibility. Or, you might want to know more about time-of-use tariffs and whether you can save money by moving your energy use to off-peak times. This page will explain everything you need to know about flexible energy use. Including how getting a smart meter can help you to access new flexible tariffs and energy-saving schemes. Read on to learn more.
What is energy flexibility?
In Great Britain, our energy system constantly balances how much energy is produced (supply) with how much is needed (demand). Energy flexibility means adjusting this balance to keep everything running smoothly.
Moving energy use away from peak times is one way to help keep this balance. For example:
You can do certain energy-intensive household chores (washing and drying clothes) on different days or at different times of day, when there is less demand for energy, or;
You can use more energy at times when more renewable energy is being generated (like on very windy or sunny days). This kind of flexible energy use is sometimes referred to as demand-side flexibility.
To promote energy flexibility, some suppliers offer energy flexibility schemes or special tariffs that offer rewards for using energy at different times. A flexible energy tariff may offer cheaper electricity rates during off-peak periods or reward customers for reducing demand at busy times. Schemes focused on electricity flexibility, encourage households to move some energy use away from peak demand periods.
Customers will need a smart meter to get all the benefits from new flexible energy tariffs.
What are peak and off-peak electricity times?
Peak times for electricity occur when energy demand is at its highest. For example, one peak time might be evenings on weekdays, when many people are getting home from work, cooking dinner, or watching TV. Off-peak energy times will be when there is less demand for energy.
If you want exact timings, check with your supplier, because peak and off-peak periods can vary by tariff and region.
Some energy suppliers offer time-of-use tariffs and flexible energy schemes that offer cheaper energy or rewards for energy use at off-peak times. They might also offer rewards for using energy when a lot of energy is generated. For example, on very windy days, more energy is generated from wind power.
You need a smart meter to take advantage of time-of-use tariffs. Click the button below to request your smart meter today.
If you have a time-of-use tariff or are taking part in a flexible energy scheme, the times when energy is cheaper, or rewards are offered, will vary depending on your supplier and the specific scheme or tariff you are using.
Quick summary: peak vs off-peak electricity
In short:
Off-peak periods are often overnight or at weekends (however peak times vary by tariff and region)
Some off-peak energy tariffs offer cheaper electricity during quieter periods
Smart meters are needed for many newer flexible tariffs
What is a flexible power system?
Energy system flexibility is the capacity of an energy system to balance changes in supply and demand. At one end of the scale, electricity system flexibility might involve using large-scale batteries to add energy to the grid when there is a lot of demand. At the other end of the scale, it might involve households changing when they use energy to reduce demand during peak energy hours.
One benefit of having a flexible energy system is avoiding energy being wasted. Such as situations where energy is generated but not used.
Energy flexibility could also help to make the most of when there is more energy from renewable sources. For example, on especially windy or sunny days. In Great Britain, smart meters are helping to build a flexible energy system. To learn more, see our page about how smart meters are helping to make Britain’s energy system smarter.
Is electricity cheaper at night?
It can be, but usually only if you’re on a time-of-use tariff that offers lower rates during off-peak periods.
Learn more about your cheap times to use electricity and time-of-use tariffs with the visual below. For a full description of the image text you can click on 'continue reading'.
If you are on a time-of-use tariff, electricity will be cheaper at certain times of day, or on certain days. If you are on a fixed or standard variable tariff, your energy will cost you the same each day, at any time of day.
If you’re on a time-of-use tariff, the cheapest time to use electricity will depend on the type of tariff you’re on. Examples of time-of-use tariffs include Economy 7, electric vehicle tariffs and tracker tariffs:
Electric vehicle (EV) tariffs
Electric Vehicle (EV) tariffs are a type of time-of-use tariff that often offers lower overnight rates, which can make charging an electric vehicle cheaper.
They are typically 2-rate tariffs, where it is cheaper to use energy at night. This means that electric vehicles can be charged more cheaply overnight.
Tracker tariffs
On tracker tariffs, energy rates are based on wholesale energy prices. The cost of energy on a given day will depend on wholesale energy prices on that day.
Economy 7 tariffs
Economy 7 tariffs have two set energy price rates: an on-peak rate and an off-peak rate. The cheaper off-peak rate will apply for 7 hours out of every 24 hours, usually at night.
If you’re asking what time does night rate electricity start, your supplier can confirm the exact hours for your tariff, region and meter setup.
Economy 7 tariffs aren't suitable for everyone. They work best for homes that only use electricity, or use a very large amount of electricity. Economy 7 and Economy 10 are older time-of-use tariffs that need compatible meters, while newer flexible tariffs typically rely on smart meter readings.
Not sure what kind of tariff you're on?
If you’re not sure what tariff you’re on, talk to your supplier to find out. If you’re not on a time-of-use tariff, but are interested in flexible energy pricing, you can research the tariffs that are available to you.
Some flexible tariffs vary pricing through the day based on demand or renewable energy availability.
To access time-of-use tariffs, you would need an energy meter that works with the tariff. To access any new flexible time-of-use tariffs, you will need to have a smart meter that is set to send readings every half an hour. If you don’t already have one, your energy supplier should be able to install a smart meter for you at no extra cost.
To request a smart meter today, enter the name of your energy supplier in the box below, and we'll take you to the right place.
What time is cheap electricity?
The cheapest time to use electricity will depend on the tariff you are on and if you've signed up to any energy flexibility schemes. If you're not signed up to any schemes and you are on a fixed or standard variable tariff, energy will cost you the same at any time of day.
If you’re on a time-of-use tariff, electricity will likely be cheaper at off-peak times, when there is less demand for electricity. This could be during the night. For example, electric vehicle tariffs typically offer cheaper rates for electricity at night.
There are also flexible energy tariffs that vary day-by-day, rather than hour-by-hour. On these tariffs, the price you pay for energy might depend on the wholesale cost of energy on a given day, rather than the time of day that the energy was used.
Energy flexibility and energy saving schemes
Some energy suppliers offer energy reward schemes. These are energy saving schemes that reward customers for using energy flexibly. They may offer rewards for moving energy use or offer cheaper electricity on certain days or at certain times. These household offers are different from the energy savings opportunity scheme regulations, which apply to qualifying organisations rather than domestic tariffs.
You will need a smart meter that is working in smart mode and sending half-hourly readings to take part in energy flexibility schemes. Get ready to take part in energy saving schemes by getting a smart meter, if you don’t have one already.
The National Energy System Operator (NESO) ran the Demand Flexibility Service (DFS) scheme, which allows suppliers to reward customers for reducing their energy use at peak times.
Customers signed up for the DFS scheme through participating energy suppliers, aggregators and apps. The scheme was designed to help the nation’s electricity system manage energy demand during peak times. To take part, customers would need to have a smart meter that was operating in smart mode and set to send readings every half an hour. Contact your supplier about getting a smart meter so you’ll be ready for new energy-saving schemes when they are introduced.
Don’t know your supplier? For your gas supplier, visit Find My Supplier or call 0870 608 1524. For your electricity supplier visit uSwitch to find your local number to call.
The price you pay for energy will only vary day-to-day or by time of day if you are on a time-of-use tariff, or if you are signed up to an energy flexibility scheme. You will need a smart meter in order to sign up to a new flexible time-of-use tariff and take part in energy flexibility schemes.
FAQs about peak and off-peak electricity
What are the peak and off-peak times for electricity?
Peak periods are often around 4pm to 7pm on weekdays, while off-peak times are usually overnight or at weekends. Exact timings vary by tariff, so check with your supplier if you need to confirm what are the off peak times for electricity for your home.
Is there a cheaper time of day to use electricity?
Sometimes. If you’re on a time-of-use tariff, you may pay less during off-peak periods. If you’re on a standard tariff, the unit price usually stays the same throughout the day
What time does night rate electricity start?
There isn’t one universal start time. Economy 7 and other time-of-use tariffs can have different overnight schedules depending on your supplier, region and meter setup.
What is a flexible power system?
A flexible power system helps balance electricity supply and demand by offering cheaper energy during times when demand is lower or renewable generation is higher.
What is a flexible energy tariff?
A flexible energy tariff can offer different prices depending on the time of day, overall demand or how much renewable electricity is available.
What are off peak energy tariffs?
Off peak energy tariffs offer lower electricity rates during less busy periods, often overnight and sometimes at weekends.
What is electricity flexibility?
Electricity flexibility means changing when energy is used to help balance demand on the network and make better use of available electricity.
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Eligibility and availability vary. Consumer action required. Rewards schemes and tariffs available to selected customers from selected suppliers.