What a virtual power plant actually is
The grid has to balance supply and demand to within 1% of 50Hz, second by second. When a big generator trips offline or wind drops faster than forecast, NESO needs power injected or load reduced within seconds. Traditionally that came from large gas peakers and pumped hydro. Increasingly it comes from aggregated small assets: home batteries, EV chargers, heat pumps and smart heaters, dispatched together by software.
The software platform is the "virtual power plant". From the homeowner's point of view, you give the operator permission to discharge (or pause charging) your battery for short windows. From NESO's point of view, the operator looks like a 50MW or 200MW power station that can respond inside a second. The flexibility revenue is split between the platform, your battery brand or supplier, and you.
Three NESO markets matter for residential batteries:
- Static Firm Frequency Response (FFR). Slower (up to 30 seconds), more forgiving, and the market most residential aggregators participate in.
- Dynamic Containment, Moderation and Regulation (DC/DM/DR). Sub-second response. Almost entirely served by grid-scale batteries today.
- Demand Flexibility Service (DFS). Hour-long, consumer-facing, paid for shifting whole-home load away from peak. We covered it in detail in our Demand Flexibility Service guide.
The three UK VPPs that pay home battery owners in 2026
1. Axle Energy
Axle is the newest entrant and the most interesting one if you do not own a Powerwall. The London-based platform connects directly to your battery's cloud (Fox ESS, GivEnergy, SigEnergy, Solax via SolaXCloud, Solis via SolisCloud), without changing your energy supplier or installing any new hardware.
£1 per kWh exported during grid events. A guaranteed minimum of £10 per month while you stay enrolled. Roughly four dispatch events a month, each around 60 minutes long. No supplier switch required.
For a 5kW inverter discharging at full output for an hour, a single event pays around £5. Four events a month is £20, and most enrolled batteries clear the £10 minimum comfortably. Axle is the only operator we are aware of currently providing residential frequency services to NESO, which is what unlocks the unusually high £1/kWh dispatch rate.
2. Kraken (Octopus Energy)
Kraken is the AI platform Octopus uses to flex its smart-tariff customers. It hit 2GW of managed domestic capacity across more than 500,000 devices in July 2025, which Kraken describes as the world's largest residential VPP. Through 2026 it has continued to grow via partnerships with E.ON Next in the UK and MAINGAU in Germany.
For most UK households, "joining Kraken" means joining an Octopus smart tariff: Intelligent Octopus Go, Cosy, Octopus Saving Sessions, or the upcoming Power Pack subscription. The flexibility revenue is monetised through cheaper unit rates and Saving Sessions credits, not a separate cheque. It is real money, but it shows up as bill savings rather than a VPP line item.
3. Tesla UK Powerwall VPP
Tesla launched its UK VPP in partnership with Octopus on 17 July 2025. Powerwall owners on Octopus tariffs can opt in via the Tesla app to share their battery during grid events. Tesla quotes a headline maximum of up to £300 per month per Powerwall, but realistic annual earnings sit at £100 to £300 per Powerwall per year for most UK households. Stacked Powerwalls earn proportionally more.
Tesla Energy Ventures was granted its own UK electricity supply licence by Ofgem on 11 March 2026, so a standalone Tesla VPP independent of Octopus is plausible during the second half of 2026. We covered the wider implications in our Tesla Electric UK guide.
How much does VPP income actually add up to?
Headline rates are eye-catching, but real-world annual income depends on three things: the size of your inverter (kW), how often the operator dispatches you, and how much of each event your battery can fulfil before hitting its state-of-charge floor.
| Battery setup | Inverter | VPP | Realistic annual income |
|---|---|---|---|
| 11.5kWh LFP, mainstream brand | 5kW | Axle Energy | £120 to £240 |
| 10kWh LFP | 3.6kW | Axle Energy | £120 (floor) |
| 13.5kWh Powerwall 3 | 11.5kW peak | Tesla / Octopus | £150 to £300 |
| Any battery on Saving Sessions only | 3.6 to 5kW | Kraken (via Octopus) | £60 to £150 |
The big number to remember is that VPP income is the topping, not the base. The base is tariff arbitrage on a time-of-use plan, worth roughly £800 to £950 a year on Octopus Go for the typical UK three- to four-bed home. Our how much can a home battery save guide walks through that calculation. A VPP adds 15% to 35% on top.
Eligibility: who can actually join in 2026
UK VPPs are not yet brand-agnostic. Your battery has to expose a cloud API the operator can call. Here is the state of play as of June 2026.
| Battery brand | Axle Energy | Tesla VPP | Octopus / Kraken |
|---|---|---|---|
| Tesla Powerwall | No | Yes | Yes (via Tesla app) |
| GivEnergy | Yes | No | Indirect (Saving Sessions) |
| Fox ESS | Yes | No | Indirect |
| Solax (via SolaXCloud) | Yes | No | Indirect |
| Solis (via SolisCloud) | Yes | No | Indirect |
| SigEnergy SigenStor | Yes | No | Indirect |
| Fogstar Drift, Pylontech, etc. | Check listing | No | Indirect |
Beyond the brand list, there are three practical prerequisites:
- Smart meter in SMETS2 mode sending half-hourly readings. Without that, your supplier cannot settle on flexibility events.
- Stable internet and battery cloud connection. If your battery is offline, the VPP cannot dispatch it.
- A G98 or G99 grid connection. Most UK home batteries already comply, see our G98 vs G99 guide if you are not sure.
Tax, warranty and cycling: the three sensible questions
The friction around VPPs is not the gross income, it is what people worry about when they sign the terms.
Where VPPs go next
Two changes coming in the next 18 months matter for home battery economics.
- Market-wide Half-Hourly Settlement (MHHS). Once MHHS fully lands across all UK suppliers (the current go-live timeline runs into 2026 and early 2027), every kWh you import or export is settled in 30-minute blocks. That is the technical foundation that makes residential flexibility worth more, because suppliers stop having to use load profiles and start paying for the actual kWh you shifted.
- Locational pricing for flexibility. NESO is consulting in the second half of 2026 on locational procurement for response services, scheduled to go live in early 2027. Households in constrained network areas (parts of London, the south coast, urban Scotland) may start to earn more per dispatched kWh than households in unconstrained ones.
Both changes work in the home battery's favour. The longer-term direction of travel is unambiguous: the value of a kWh that can move when the grid needs it is rising, not falling. A 2026 VPP that pays £120 to £300 a year is plausibly worth £200 to £500 a year by 2028 for the same battery on the same tariff.
So should you sign up?
Three groups, three different answers:
Frequently asked questions
Will a VPP drain my battery when I need it?
No. Every reputable residential VPP, including Axle, Tesla and Kraken-driven dispatch, lets you set a reserve floor (typically 20% to 30%) below which the operator will not discharge. Events are also short, around 60 minutes for Axle, and the platform avoids dispatching during peak hours when you usually need the battery yourself.
What happens during a power cut?
VPP dispatch only happens while the grid is up and your battery is grid-connected. During an actual power cut, the VPP cannot reach your inverter and your battery defaults to whatever backup behaviour it is wired for. Our home battery backup power guide covers what to specify when buying a battery if outage cover matters to you.
Can I leave a VPP if I change my mind?
Yes. All three major UK VPPs let you opt out at any time with no exit fee. Axle and Tesla disconnect through their app; Octopus-driven dispatch ends as soon as you leave the smart tariff. Read the specific terms before signing, particularly any minimum enrolment period during a beta or trial.
Does a VPP work without solar panels?
Yes. A VPP cares about your battery's ability to discharge into the grid on demand, not about how it was charged. A standalone home battery on Octopus Go, the setup we specialise in, qualifies for Axle's residential frequency service as long as the underlying brand is supported. We explain the wider economics of battery storage without solar for households that do not want the panels.
Will the Habo Energy battery support VPPs?
Habo Energy's 11.5kWh system is built on hardware platforms that already integrate with UK VPP operators, so households that want to enrol can do so once installed. We track the operator landscape, including Axle, Kraken and Tesla, and surface the right onboarding path for your tariff during installation. Tariff arbitrage on Octopus Go remains the larger source of savings, and the VPP layer stacks cleanly on top.
Stack tariff savings with a VPP top-up
Reserve your Habo Energy battery: a simple, affordable 11.5kWh all-in-one home battery, MCS-installed and ready to capture both Octopus Go arbitrage and the £120 to £300 a year a UK home battery can earn from a virtual power plant on top.
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