What is the Demand Flexibility Service?
The UK electricity grid needs supply and demand to balance every second of every day. When demand spikes, typically between 4pm and 7pm on weekday evenings, the grid operator has traditionally fired up gas peaker plants to cover the gap. These are expensive and carbon-intensive.
The Demand Flexibility Service (DFS), run by the National Energy System Operator (NESO), takes a different approach. Instead of generating more electricity during peak demand, it pays households to use less. If enough households reduce demand by even a small amount at the same time, the effect is equivalent to switching on a power station, without burning any gas.
The scheme launched in winter 2022 as a trial. By 2025, it had become a year-round service with over 2.4 million household participants. In April 2026, DFS v4 introduced significant new features including bi-directional flexibility and regional zonal pricing.
How a DFS session actually works
Here is the typical sequence of events:
- NESO forecasts a period of high grid stress, usually 24 to 48 hours ahead.
- Your energy supplier notifies you via app or email, inviting you to opt in to a session (typically 30 to 60 minutes, between 4pm and 8pm).
- During the session, your battery discharges and powers your home instead of drawing from the grid. Your smart meter records the reduction against your usual baseline consumption for that time of day.
- After the session, your supplier calculates your reward based on how much demand you reduced compared to your baseline, and credits it to your account.
The beauty for battery owners is that steps 3 and 4 can be near-automatic. Smart inverters on systems like Tesla Powerwall, GivEnergy, and SolarEdge can be set to discharge during DFS windows without any manual action. You opt in once, and the battery handles the rest.
How much will you earn?
Earnings depend on the session rate and how much demand you reduce. The rates set by NESO have ranged from £2.25 to £3+ per kWh across different sessions.
| Battery size | Demand reduced per session | Earnings per session (at £2.50/kWh) | Estimated annual earnings (10 sessions) |
|---|---|---|---|
| 5 kWh | ~4 kWh | ~£10 | ~£100 |
| 10 kWh | ~8 kWh | ~£20 | ~£200 |
| 11.5 kWh | ~9 kWh | ~£22.50 | ~£225 |
| 15 kWh | ~12 kWh | ~£30 | ~£300 |
These figures use a conservative estimate of 10 sessions per year, but with the DFS now running year-round, some battery owners are seeing 15 to 20 sessions annually. NESO projections suggest committed battery participants can earn well over £300 per year once the service matures further.
For context, the highest single-session payment recorded by SolarEdge in their battery DFS trial reached £25.60. The average per session was £6.52, and that was from an earlier iteration of the scheme when rates were lower.
Manual vs. battery participation
Manual participants (those turning off appliances by hand) typically reduce demand by less than 0.5 kWh per session. Battery participants routinely deliver 5 to 10 kWh. That is a 10x to 20x difference, which is reflected directly in earnings. A battery is the most effective way to participate in the DFS.
What changed in DFS v4 (April 2026)
The April 2026 update introduced three meaningful changes for battery owners:
Bi-directional flexibility
Previously, DFS only paid you to use less electricity. Now it can also pay you to use more, specifically when the grid has excess renewable generation (typically midday on sunny or windy days). Battery owners can charge during these surplus periods and earn for doing so. This is called demand turn-up, and it makes your battery even more valuable as a grid asset.
Zonal procurement
The DFS now operates across 12 regional zones. Rates can vary by zone depending on local grid constraints. If your area has a particular bottleneck, you may receive higher payments than the national average. This is a significant shift from the one-size-fits-all approach of earlier DFS iterations.
Lower eligibility threshold
The minimum threshold for participating aggregators was reduced from 1MW to 0.1MW, making it easier for smaller providers and community energy groups to participate. In practice, this means more suppliers will be offering DFS access to domestic customers over the coming months.
Which suppliers offer DFS access?
You cannot sign up directly with NESO. Participation is managed through your energy supplier or a licensed aggregator. The main options for UK households are:
Other participating suppliers include OVO Energy, British Gas, and EDF Energy, each with their own branded versions of the scheme. The underlying payment rates come from the same NESO auction, so the earnings potential is broadly similar across providers.
To participate you need: a smart meter with half-hourly readings enabled, an account with a participating supplier, and to opt in via your supplier's app or website before each session (or set up automatic opt-in where available).
DFS earnings on top of tariff arbitrage savings
The DFS is not a replacement for the main financial benefit of a home battery, which comes from charging overnight on cheap electricity and using it during the day. It is an additional income stream on top.
A typical 10 to 12 kWh battery on Octopus Go saves £400 to £600 per year through tariff arbitrage alone. Adding DFS participation can push total annual earnings closer to £700 or more.
| Income source | Annual value (10–12 kWh battery) |
|---|---|
| Tariff arbitrage (Octopus Go, charging at 9.5p, using at ~32p) | £400 to £600 |
| Demand Flexibility Service sessions | £200 to £350 |
| Smart Export Guarantee (if you have solar) | £50 to £150 |
| Total potential annual earnings | £650 to £1,100+ |
The DFS payments also improve your payback period. If you are assessing whether a battery is worth it, DFS income should be factored in, since it genuinely shortens the time to break even.
Practical tips for maximising DFS earnings
Automate where possible
Set your inverter or battery management software to discharge automatically during DFS windows. Manual opt-in is required with most suppliers today, but automation means you will not miss a session while you are out or asleep.
Check your baseline
DFS payments are based on how much your consumption drops compared to your typical usage at that time of day. If you normally use very little electricity at 6pm, there is less room to show a reduction. Larger households with higher baseline usage at peak times will earn more per session.
Time your battery charging
To maximise what your battery can deliver during a DFS event, make sure it is fully charged before sessions typically start. On Octopus Go, the cheap rate runs from 00:30 to 05:30, giving plenty of time to charge overnight and be ready for an evening session.
Monitor regional rates
With zonal procurement now in place, it is worth checking whether your region receives premium rates. The UK Battery Tracker will be updated with regional DFS data as it becomes available.
The UK's Clean Flexibility Roadmap published by the government sets out plans to significantly expand grid flexibility through 2030. Battery owners who participate in the DFS now are establishing a track record and getting ahead of a growing income opportunity.
Summary: is it worth participating?
Yes, with almost no downsides for battery owners. The main points:
- You earn £200 to £350+ per year in addition to your normal tariff savings.
- Participation is mostly automated once set up correctly.
- Sessions last 30 to 60 minutes and have minimal impact on your daily life.
- The DFS has become year-round, so earning opportunities are no longer limited to winter.
- DFS v4 adds demand turn-up, meaning batteries can also earn from surplus renewable generation.
If you are evaluating how much a home battery can save you, DFS earnings are a real and growing part of that picture. They are not hypothetical. The scheme has paid out to millions of UK households and is backed by NESO with government support.
Ready to start saving?
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