Energy dataLast updated: Latest published event 2026-09-07

The Demand Flexibility Service

Contents

Most of what a household can do about energy prices is buy the same electricity more cheaply. The Demand Flexibility Service is one of the very few schemes that pays for something else: using electricity at a different time.

It is run by the National Energy System Operator, it covers England, Scotland and Wales, and a household reaches it through a supplier or an aggregator rather than directly. This page sets out what has actually happened — when events have run, in which direction, how much flexibility was bought and who bought it — from NESO’s own published record.

One thing first, because it is the most common misunderstanding: this is not a winter scheme. It was, until 27 November 2024. Since then it has run all year, including through the summer.

What the service is

When the electricity system expects to be tight, NESO publishes a requirement for a particular window — a number of megawatts it would like demand to move by. Registered participants bid to deliver some of it, at a price of their choosing. NESO accepts the bids it needs, cheapest first, and settles afterwards against what was actually delivered.

That requirement is published as megawatts for one half hour at a time, and everything below adds those half hours together, so the totals on this page are in megawatt-hours rather than megawatts. Where a megawatt figure does appear it is a mean across the half hours it covers, labelled as one. Nothing here is a peak: NESO publishes the requirement and the volume bought per period, and a largest half hour cannot be recovered once they have been added up.

A household never appears anywhere in that process. Your supplier or aggregator aggregates thousands of homes into a single bid, and what you are offered is that company’s own scheme, on its own terms, under its own name. The prices further down this page are what those companies bid, per megawatt-hour, and they are not what anyone is paid at home.

Two directions, and what each asks of you

The service began as one thing: be paid to use less at the evening peak. It now runs in two directions, and the newer one asks the opposite. The two are set out separately below, and deliberately not as two halves of a chart — one of them is almost the entire service and the other has so far bought almost nothing.

Being paid to use less

Turn things off, or run them later, during the window.

Energy bought: 9,619.8 MWh
Energy asked for: 154,810 MWh
Days it ran: 76

The energy bought is 6% of the energy asked for, over the same 652 half-hour periods. This is almost the whole of the service. Payment reaches a household through its own supplier or aggregator, on that company's terms.

Being paid to use more

Run things during the window that you would otherwise run later.

Energy bought: 0.5 MWh
Energy asked for: 68,600 MWh
Days it ran: 36

The energy bought is less than 0.01% of the energy asked for, over the same 304 half-hour periods. Published in the same file and barely used. Most of these auctions bought nothing at all, and those zeros are real published results rather than missing data.

Before the direction was published

NESO’s earlier file has no direction column, so these 1,132 half-hour periods across 190 days are recorded without one. They ran in the late afternoon and evening and were almost certainly all turn-down, but a column that is sometimes a guess is worse than one that is sometimes empty, so they are kept apart from both figures above rather than folded in.

13,491.8 MWh bought, across 1,132 half-hour periods (566 hours), 23.8 MW in an average half hour, 29 November 2024 to 27 March 2026.

Every figure above is energy. NESO publishes a megawatt figure for each half hour, and a megawatt-hour here is those figures multiplied by half an hour and then added up — adding the megawatts themselves would give a number in no unit at all. The megawatt figures beside them are means across those half hours. Nothing here is a peak: this record publishes no largest half hour, and one cannot be recovered from a total.

How the direction is worked out

This is the part where getting it wrong would matter most, so it is worth being explicit about what is known and what is inferred.

How we know which way round it is

NESO labels each event Upwards or Downwards and publishes no definition of either. Read one way they are the system’s direction, read the other they are the household’s, and the two are opposites. What settles it is when each kind runs.

Events labelled Upwards run 10:00 to 14:00:59 UTC, across 304 half-hour periods on 36 days.
Events labelled Downwards run 14:00 to 21:00:59 UTC, across 652 half-hour periods on 76 days.

The middle of the day is when Britain has surplus solar and wind; the early evening is when it has least to spare. So Upwards asks households to use more and Downwards asks them to use less. That is a reading of the published clock, not something the publisher states, and it is re-checked against the data every time this page is built.

When it has actually run

DFS is episodic. It is called when the system needs it, which means there are stretches of weeks with nothing at all, inside seasons that are plainly running normally. A month missing from the table below had no events; it did not have events worth nothing.

When events have run

294 days across 23 months, from 29 November 2024 to 7 September 2026. Months with no events are not listed — there is no such thing as a nil month here, only a month in which the service was not called.

Demand Flexibility Service events by month
Month	Days with events	Energy bought to use less	Energy bought to use more
September 2026	6	907.7 MWh	0 MWh
August 2026	23	2,963.2 MWh	0 MWh
July 2026	17	1,768.4 MWh	0 MWh
June 2026	23	2,253.3 MWh	0.1 MWh
May 2026	22	1,286.9 MWh	0.4 MWh
April 2026	13	440.4 MWh	0.1 MWh
March 2026	8	827.3 MWhdirection not published	not offered
February 2026	3	241.2 MWhdirection not published	not offered
January 2026	15	860.2 MWhdirection not published	not offered
December 2025	6	207 MWhdirection not published	not offered
November 2025	7	638.5 MWhdirection not published	not offered
October 2025	11	875.2 MWhdirection not published	not offered
September 2025	12	1,100.8 MWhdirection not published	not offered
August 2025	13	641.1 MWhdirection not published	not offered
July 2025	18	808.7 MWhdirection not published	not offered
June 2025	15	783.1 MWhdirection not published	not offered
May 2025	12	544.5 MWhdirection not published	not offered
April 2025	13	505.9 MWhdirection not published	not offered
March 2025	18	1,957.5 MWhdirection not published	not offered
February 2025	16	1,839 MWhdirection not published	not offered
January 2025	10	1,335.6 MWhdirection not published	not offered
December 2024	12	326.5 MWhdirection not published	not offered
November 2024	1	0 MWhdirection not published	not offered

Each energy figure is that month’s published megawatts for each half hour in that direction, multiplied by half an hour. No mean megawatt figure is shown per month, because the publisher’s month totals come with one period count covering both directions and dividing by it would be a mean over the wrong denominator.

By season

A season here runs from 1 April, taken from each event’s own delivery date. Test events are listed separately from live ones and are never added to them.

Demand Flexibility Service by season and requirement type
Season	Kind	Days	Energy bought	Average power bought	Cost of accepted bids
2026-27	Live	104956 half hours	9,620.3 MWh	20.1 MWmean, not peak	£1.58m
2026-27	Test	28 half hours	192.4 MWh	48.1 MWmean, not peak	£34k
2025-26	Live	133822 half hours	8,033.3 MWh	19.5 MWmean, not peak	£1.07m
2024-25	Live	57310 half hours	5,458.5 MWh	35.2 MWmean, not peak	£1.23m

384 half-hour periods are still waiting to be settled and 1,712 have been. A period awaiting settlement is blank, never a zero.

How a household takes part

Through the company that supplies your electricity, or through an aggregator that works with your smart charger, battery or heat pump. The list below is who bid into the most recent season. It is the most directly useful thing in this data, because it answers the only question a household can act on: is anybody I could realistically be with actually doing this?

Who took part in 2026-27

These are registered participants — suppliers and aggregators — not households. A household reaches the service through one of them, under that company’s own scheme name and its own terms. The prices are what the company bid per megawatt-hour, which is not what anyone is paid at home.

Registered Demand Flexibility Service participants for the latest season
Participant	Accepted energy	Days bid into	Bid price range
INFINIS LIMITED	6,615 MWh	65	£94 to £379 per MWh
OCTOPUS ENERGY LIMITED	1,965.2 MWh	35	£145 to £649 per MWh
HILDEBRAND TECHNOLOGY LIMITED	587 MWh	42	£112.9 to £386.8 per MWh
EQUIWATT LIMITED	202.6 MWh	46	£105 to £250 per MWh
Edgware Energy Limited	129.5 MWh	1	£180 to £180 per MWh
OAKTREE POWER LIMITED	81.4 MWh	42	£25 to £284.3 per MWh
AXLE ENERGY LIMITED	66.7 MWh	20	£160 to £987.4 per MWh
St Breock Limited	55.5 MWh	4	£170 to £170 per MWh
Sancton Hill Limited	41.7 MWh	4	£170 to £170 per MWh
U ENERGY GROUP LIMITED	22.2 MWh	50	£90 to £250 per MWh
Electric Miles Limited	16.5 MWh	6	£132.5 to £135 per MWh
Goonhilly Limited	14.7 MWh	2	£170 to £170 per MWh
DRAX ENERGY SOLUTIONS LIMITED	6 MWh	1	£500 to £500 per MWh
Shuffle Energy Limited	4.9 MWh	18	£20 to £210 per MWh
ENGIE POWER LIMITED	4 MWh	1	£196 to £196 per MWh
GRIDVOLT UK LIMITED	0.1 MWh	3	£150 to £170 per MWh
Bryt Energy Limited	0.1 MWh	1	£100 to £100 per MWh
CUB (UK) LTDregistered but never bid	0 MWh	0	—
GRIDIMP LIMITEDregistered but never bid	0 MWh	0	—
South Sharpley Limitedregistered but never bid	0 MWh	0	—

Accepted energy is every accepted bid’s megawatts multiplied by the half hour it was bid for, added up across the season. It is not a capacity and says nothing about how much a company can shift at once: no mean is offered either, because a participant may hold more than one accepted bid in the same half hour, so the bid count is not a count of half hours.

Being on this list means a company bid into the service. It does not mean every one of its customers was offered a place, and it does not say what share of a bid price reaches a household.

In practice you will need a smart meter sending half-hourly readings, or a device the aggregator can measure directly. The payment is worked out by comparing what you used during the window against what you would normally have used at that time, and there is no way to do that from a quarterly reading.

If your supplier is not on the list, the honest answer is that you cannot take part through them this season. Whether it is worth moving supplier for it is a different question, and one the cheapest and cleanest hours page is more use for: a time-of-use tariff pays for shifting demand every day rather than on the handful of days DFS is called.

What this page cannot tell you

Whether there is an event today. NESO publishes a same-day requirement at around a quarter past ten in the morning for an event that can start three quarters of an hour later. The data behind this page refreshes every six hours, which is right for a historical record and useless as an alert. If you are signed up, the notification comes from your supplier.

What you would be paid. Every price here belongs to a registered participant and is quoted per megawatt-hour at their meter boundary. What reaches a household is whatever that company chooses to pass on, and this dataset says nothing whatever about it.

What happens on a day with no event. Nothing, and the data records nothing. There is no row for a quiet day, so nothing on this page should be read as a payment of zero — only as the service not having been called.

Northern Ireland. This is a Great Britain balancing service. Northern Ireland is on the all-island system operated by SONI and is not covered.

Source and scope

National Energy System Operator: the Demand Flexibility Service requirement, utilisation and settlement files, one row per event and half hour. Great Britain. Settlement arrives weeks after delivery, and a period that has not settled is shown as blank rather than as zero. Supported by National Energy SO Open Data National Energy SO Open Data Licence v1.0

Read the methodology.

Frequently asked questions

What is the Demand Flexibility Service?

A scheme run by the National Energy System Operator that pays electricity users to shift their demand out of the periods when the system is tightest. Households take part through their supplier or through an aggregator, not directly with NESO, and payment usually arrives as bill credit or as points under whatever the company calls its own scheme.

Is the Demand Flexibility Service only in winter?

No. It was a winter service when it launched, but it became year-round on 27 November 2024 and has had events in every month since, summer included. Anything describing it as a cold-evening scheme is describing how it worked before that change.

How much does the Demand Flexibility Service pay?

That depends entirely on your supplier or aggregator, and this dataset cannot tell you. What it publishes is what the participating company bid, per megawatt-hour, at its own meter boundary. How much of that reaches a household, and in what form, is set by that company’s own scheme terms.

Do I need a smart meter to take part?

In practice yes. Payment depends on comparing your consumption during the event with what you would normally have used at that time, which needs half-hourly meter readings. Some routes into the service use a compatible smart charger or battery instead, but all of them need something reporting your usage at half-hourly resolution.

Is there an event today?

This page cannot tell you. The requirement for a same-day event is published around 10:15 in the morning for an event that can begin 45 minutes later, and the data behind this page refreshes every six hours. If you are signed up, your supplier or aggregator will contact you; this page is the record of when the service has run, not an alert that it is running.

What does an Upwards event mean?

It means the system wants demand to go up: you are being paid to use more electricity than you otherwise would, typically in the middle of the day when there is surplus wind and solar. Downwards is the familiar case — being paid to use less, usually in the early evening. NESO publishes both labels without defining either, so we read them from when each kind of event actually runs, and the page shows that working.