Drax Group Signs 250MW Battery Storage Tolling Agreement in Strategic FlexGen Expansion

Drax signs 250MW battery storage tolling deal at West Burton – here’s what it means

Drax Group (LSE: DRX) has agreed a tolling deal for 250MW (500MWh) of new battery energy storage (BESS) at West Burton, England, with West Burton C Limited, owned by developer Fidra Energy. In plain English: Drax will control and operate a large two-hour battery, but won’t pay to build it.

This is a capital-light way to expand Drax’s flexible generation (FlexGen) footprint, with the developer taking construction and availability risk. It adds fast-response capacity that can earn from trading power and grid services, aligning tightly with the UK’s push for energy security and decarbonisation.

How the tolling agreement works (and why the structure matters)

A tolling agreement is a long-term contract where the asset owner builds and maintains the kit, while the offtaker controls how it runs and keeps the operating revenues.

• Capacity: 250MW, two-hour duration (500MWh) at West Burton, England.
• Capital-light for Drax: No upfront capital cost; construction, maintenance and availability risk sit with Fidra.
• Tenor: 10 years from the Commercial Operation Date (COD).
• Payments: Fixed annual tolling fee indexed to UK CPI (consumer price inflation).
• Control: Drax gets full operational control and dispatch rights.
• Revenues: Drax retains all operating revenues, excluding Capacity Market revenues (not retained by Drax).
• Grid: Protected grid connection in place, a valuable de-risking feature.
• Returns: Expected to be significantly ahead of Drax’s Weighted Average Cost of Capital (WACC).

Key numbers at a glance

Item	Detail
Capacity and duration	250MW, two-hour (500MWh)
Commercial structure	10-year tolling agreement, CPI-indexed annual fee
Capex exposure	No upfront capital cost for Drax
Operational rights	Full operational control and dispatch rights for Drax
Revenues	All operating revenues retained by Drax, excluding Capacity Market
Grid connection	Protected connection
Returns	Significantly ahead of Drax’s WACC (exact figure not disclosed)

Strategic fit: building out FlexGen with BESS and optimisation

Drax is building a gigawatt-scale pipeline across two pillars: physically owned batteries and the capability to optimise third-party assets via route-to-market, floor, and tolling structures. This deal lands squarely in the second bucket.

It complements recent moves. In October 2025, Drax agreed to acquire three BESS projects totalling 260MW when fully commissioned, and in January 2026 it bought Flexitricity, an optimisation platform that should sharpen Drax’s ability to dispatch and monetise flexible assets like batteries. Together, these steps create a more complete FlexGen business – owning some assets, and controlling others – with the potential for diversified earnings.

Revenue stack, inflation linkage and expected returns

The company expects returns on this contract to be significantly ahead of its WACC, which is a positive signal for value creation. While the tolling fee is CPI-indexed (which increases Drax’s cost base over time), battery revenues typically come from wholesale trading and grid services that can also reflect inflation and system volatility. Put simply, the revenue opportunity should be more than enough to cover the indexed fee if markets behave as Drax expects.

One nuance: Capacity Market revenues are excluded from what Drax retains. Those revenues can be meaningful in some years, so they’re a missed upside for Drax here. However, avoiding capex and shifting construction and availability risk to Fidra is a strong trade-off that supports a capital-light return profile.

Timelines and a notable COD discrepancy to watch

The highlights flag a “targeting COD in 2028” with a protected grid connection. However, the agreement is also described as being subject to Fidra taking a final investment decision (FID) by Q3 2026 and achieving commercial operations by H2 2029. That is a clear discrepancy between 2028 and H2 2029.

Reason for the mismatch is not disclosed. The prudent read is to treat H2 2029 as the contractual long-stop or latest window, with 2028 as an earlier target. Either way, investors should watch for FID by Q3 2026 and any schedule updates from Fidra or Drax.

Why this matters for the UK power system

Short-duration, fast-response batteries are crucial for balancing a renewables-heavy grid. They soak up excess power when it’s windy or sunny and discharge when demand tightens. This supports energy security, helps decarbonisation and can lower system costs.

By adding 250MW of BESS control without tying up large amounts of capital, Drax is scaling its flexible fleet in a way that should be cash-efficient and repeatable. It’s also aligned with policy direction: more storage to stabilise the system as coal and unabated fossil generation exit.

Josh’s take: positives and watch-outs

• Capital-light growth: No upfront capital, yet full dispatch rights. That’s powerful leverage to Drax’s trading and optimisation capabilities.
• Return signal: “Significantly ahead of WACC” suggests this should be value accretive if markets hold up.
• Strategic coherence: Tight fit with the FlexGen plan, and neatly complements the Flexitricity acquisition and prior BESS project purchases.
• Inflation indexation: CPI-linked fees lift costs, but the revenue stack can move with inflation and volatility. Balanced, not a deal-breaker.
• Capacity Market exclusion: Drax doesn’t retain CM revenues here. Not ideal, but the trade-off is reduced capex and risk.
• Timeline risk: The 2028 vs H2 2029 COD discrepancy and FID dependency introduce timing uncertainty.

What to watch next

• FID by Q3 2026: This is the next hard milestone for the project to proceed.
• COD clarity: Any update reconciling the 2028 target with the H2 2029 reference.
• Commercial terms detail: Toll fee level is not disclosed; any colour on price floors or ancillary revenue strategy would be useful.
• Integration with Flexitricity: Evidence that Drax’s optimisation platform squeezes superior value from BESS dispatch.
• Progress on the 260MW BESS acquisitions: Commissioning timelines and stacking know-how across owned and tolled assets.

Bottom line

This is a tidy, capital-light expansion of Drax’s battery portfolio that leans on its growing optimisation muscle. The structure shifts build and availability risk to the developer while giving Drax the revenue upside – minus the Capacity Market slice. The return guidance is encouraging, though investors should keep an eye on FID and the COD timeline.

On balance, strategically smart and financially sensible – with timing the key variable to monitor.