We are becoming a separate company

In April 2019, the Electricity System Operator is becoming a separate company within the National Grid Group. Find out more about what this change will mean.

Demand turn up

The demand turn up (DTU) service encourages large energy users and generators to either increase demand or reduce generation at times of high renewable output and low national demand. This typically occurs overnight and during weekend afternoons in the summer. Find out about routes to market as a provider.

The entry threshold for participation is 1 MW. This can be aggregated from sites 0.1 MW and larger.

Fractions of megawatts are acceptable, e.g. 4.2 MW, providing they meet the entry threshold.


Providing you have minute by minute or half hourly metering on your site(s), a mobile phone/landline and the ability to access email, there is no additional equipment that needs to be installed.

Delivery duration of the service

In 2016, the average length of delivery was 4 hours 20 minutes.

In 2017, the average length of delivery was 3 hours 34 minutes.

However, each instruction depends on a number of factors, including the weather conditions and the provider’s capabilities.

We will ask you how long you are capable of providing demand turn up for in a single instruction and we won’t exceed this when we issue instructions.

Speed of delivery

As with duration of delivery, the speed in which a provider needs to respond is linked to individual providers’ capabilities.

The average notice period for an instruction (i.e. the time between a provider receiving an instruction and starting to deliver the service) was 7 hours 20 minutes in 2016 and 6 hours 40 minutes in 2017. This may differ in 2018, depending on how far in advance we can identify our requirement, but we will only issue instructions that providers have told us they have the capability to meet.

Service dispatch

When providers need to be available to deliver the service

There are particular times of the day or week when the service is more likely to be required. These are defined as ‘availability windows’ and cover the following periods:

Overnight window:

  • 23:30 – 08:30 for May, September, October (base months)
  • 23:30 – 09:00 for June, July, August (peak months)

Weekends and bank holidays afternoon window:

  • 13:00 – 16:00 for May to October

How providers will be dispatched

Instructions will be issued via email, with a supporting SMS sent to the provider.

We will send an email containing the details of the megawatt response and the timeframes during which it is required.

Providers will need to confirm receipt of an email instruction within 30 minutes of it being issued.



There is no commitment to be available 24/7 or for every availability window.

Providers submit availability reports to declare the megawatts they have available for demand turn up. This can be done on a weekly basis or, if you know what your availability will be for a prolonged period, it can be between a range of dates or ‘until further notice’.

Once you have declared yourself available, you’ll need to be prepared to deliver demand turn up if instructed. Failure to do so will be treated as non-delivery.

Optional windows

The periods in between availability windows are classed as ‘optional windows’. During these periods, there is likely to be a reduced requirement for demand turn up. Providers can declare themselves to be available during these optional windows, and receive a utilisation payment only.