Operator:  SSDC Opium Power
Optimiser:  Limejump
Location:  Fareham
Capacity: 87MW
Number of Sites: 2


SSDC Opium Power is a joint venture between Opium Power and South Somerset District Council (SSDC), the first council to invest in batteries in the UK. Forming in 2018, we have collaboratively developed and built 88MW of grid scale battery energy storage systems (BESS), the final 20MW went live in July 2022. The JV has two key objectives, firstly to reinforce the pioneering SSDC’s drive towards Net Zero, and secondly, to generate additional income to fund public services.

A unique partnership

Limejump has been collaborating with SSDC Opium Power since 2021, providing guidance and support throughout the development and build of our newest battery project: Fareham Phases 1 and 2, a 40MW (Phase 1) and a 20MW (Phase 2) Battery Energy Storage System (BESS) located over county lines in Hampshire. Fareham is the UK’s largest BESS that is owned by a local authority. During the tendering process of Fareham, Limejump also suggested taking on the optimisation services of SSDC Opium Power’s 28MW Fideoak battery that has been in operation since 2020. We were impressed by their knowledge, experience and optimisation offering and Limejump was successful in their bid and commenced onboarding both assets to the platform.

Maximising revenue for the customer

Batteries are not an easily ‘hedgeable’ asset in the traditional sense like a gas peaker, due to their ‘short duration’. In the UK, utility-scale batteries earn revenue through participating in ancillary markets and trading in volatile prompt power markets – providing power when supply is scarce and being a source of demand when markets are oversupplied. Limejump has extensive battery optimisation experience, equating to over 50,000 hours managing grid-scale batteries in the UK, and has built a vast amount of proprietary software to help optimise and schedule battery assets across different markets.

Limejump is optimising both SSDC Opium Power’s Fideoak and Fareham sites across several markets, from National Grid’s ancillary services, such as Dynamic Containment, to trading in the more volatile wholesale markets.

How Limejump stacks revenue

Firstly, it is important to define what is meant by ‘Revenue Stacking’. Revenue Stacking is a fairly new phenomena in the energy storage world and has become more prevalent as more and more market opportunities open up. Simply put, optimisers, such as Limejump, place an asset in multiple markets delivering multiple services at the same time. Limejump do this by utilising both their experienced trading desk and technology platform to ‘bid in’ assets into multiple markets to optimise captured value within various service and system constraints. These ‘markets’ include ancillary services such as the Dynamic Containment (DC), Dynamic Regulation, Dynamic Moderation, the Capacity Market, the Balancing Mechanism and wholesale markets such as the day-ahead and intra-day.

A great example, that showcases Limejump’s stacking capability, was on the 1 May 2022 where they successfully optimised Fideoak in a number of markets over a 24-hour period. Limejump’s platform was able to stack vertically by withholding bid volumes in DC, when more valuable to do so, to open up some head/footroom for wholesale trades. Limejump’s trading and dispatch team were then able to successfully utilise their price forecasting capability to trade in the day-ahead and intra-day wholesale markets, allowing their asset to charge when prices were low and discharge in the peak of the day. This captured additional revenue all whilst participating in DC high and low frequency within its service requirements.

A growing collaboration

With the successful onboarding of our existing Fideoak battery and the optimisation of the two new Fareham batteries, Limejump and SSDC Opium Power’s relationship and portfolio has grown to 88MW. The Fareham site increases its traded capacity from 40MW to 60MW in September 2022, as the further 20MW has been added after the initial 40MW battery was successfully optimised.

Limejump will continue to ensure that SSDC Opium Power’s battery assets are optimised in the right markets at the right time, whilst also ensuring the assets’ health is maintained.