Reducing CAPEX in your BESS projects, without taking on integration risk
by RES | May 21, 2026 | Reading time: 4 min
By Priyanka Parekh, Senior Sales Engineer
Battery costs have fallen sharply. According to BloombergNEF’s 2025 Energy Storage Systems Cost Survey, the global average turnkey BESS price dropped 31% year on year. The question worth asking is where the next opportunity for cost reduction sits. The answer, more often than not, is in the integration approach.
For developers and asset owners building battery storage today, the most consequential commercial decision is rarely the one that gets the most attention. Battery procurement, interconnection and offtake dominate the project development conversation. The controls contract, the EMS, PPC, SCADA and security architecture that sits on top, gets treated as a technical line item – often folded inside a turnkey package and left there.
This habit costs money. The turnkey model has historically been justified by the simplicity of one contract and one accountable supplier. But the premium attached to that simplicity has become significant, and it is increasingly avoidable. A disaggregated approach to BESS delivery can make meaningful reductions in project CAPEX, provided the controls scope is genuinely integrated under a single partner rather than left as a gap between vendors.
This distinction matters. The reason disaggregation has historically been difficult is not that customers couldn’t see the savings. It is that breaking apart the contracts has typically meant taking on integration risks, additional interface management and accountability headaches the customer wasn’t set up to absorb. When something went wrong at commissioning, fingers pointed across multiple contracts and savings evaporated.
RESolve is built around addressing that tension. It is RES’ proprietary Energy Management System and Power Plant Controller, and it ships as part of a broader controls scope that includes SCADA, the Electronic Security Perimeter, grid modeling and the BESS engineering expertise required to commission and operate the system. That scope is delivered under one contract, by one partner, with the technical depth to take ownership at every step.
The commercial implication is that customers can move away from turnkey procurement without taking on the delivery risk that has historically come with disaggregation. Battery, inverter and balance of plant procurement can be competitively tendered. The controls and commissioning scope is owned end to end by RES. Project CAPEX comes down without anything being added back as risk premium.
What “integrated controls scope” actually means
Most BESS controls vendors offer a piece of this stack. Some provide EMS software. Others bundle a PPC inside a hardware-led offering. SCADA is often a separate contract. The Electronic Security Perimeter, the cybersecurity boundary around the controls network, is increasingly subject to NERC CIP, NIS2 and equivalent regional requirements and is typically a fourth contract, often with a fourth supplier. And the most important – project level commissioning, often falls to a collective of companies looking out for their own scope. Each of those interfaces is a place where delivery risk accumulates, and each one that must be managed by the customer’s project team adds cost that rarely shows up on the controls line item but is very real once commissioning starts.
What is genuinely difficult to find in the market is a single partner taking responsibility for the entire controls stack and project commissioning – EMS, PPC, SCADA and Electronic Security Perimeter, alongside the grid modeling and BESS engineering required to make it all work against the connection agreement. Those scopes turn into the tool that enables smooth project commissioning – sitting at the center of the project’s integration they allow rapid identification and rectifying of commissioning issues. This end-to-end scope is what allows the disaggregated procurement model to work commercially: the savings from competitive battery and PCS tendering are real, and the integration risk that would otherwise erase them is held by a partner with the technical depth to do so.
Why the partner matters as much as the scope
The case for multi-contract procurement only holds if the customer has confidence that the controls partner can deliver. That confidence is not built on a product roadmap. It is built on having designed, commissioned and operated battery assets across the conditions a project is likely to encounter.
RES is an early pioneer in battery storage, and in the controls systems required to operate those assets safely, compliantly and efficiently. RESolve has been delivered across more than two dozen sites and has over 140 project years of operational experience, spanning 12 electricity markets and 11 battery and inverter OEMs. The sub-90 millisecond system response achieved for the Irish DS3 market and the eight stacked frequency services running on a virtual battery in Sweden are examples of what the platform delivers in practice.
The decision in front of you
The case for turnkey procurement is one of simplicity. The case against it is increasingly one of cost. For developers and IPPs facing tight project economics and competitive bid processes, the CAPEX recoverable through disaggregation is significant and the integration risk that has historically blocked the move is precisely what an integrated controls scope under a single accountable partner is designed to remove.
Battery pricing has already been optimized by market forces. The controls contract is where the remaining opportunity sits. For asset owners weighing that decision at the start of a project, the combination of meaningful CAPEX reduction and unchanged delivery risk deserves more scrutiny than the line item usually receives.
About:
Priyanka Parekh, Senior Sales Engineer
Priyanka is a Senior Sales Engineer focused on helping customers translate advanced digital technologies into practical, real-world value. With a background in software engineering and product management, she brings a combination of technical depth and strategic perspective to help organizations better understand, operate, and optimize their portfolios.
She has supported digital innovation initiatives globally across wind, solar, energy storage, and hybrid projects. Her work centers on enabling operators to leverage controls solutions, analytics, automation, and advanced diagnostics to reduce project risk, optimize CAPEX, minimize downtime, and improve operational decision making.
Priyanka is passionate about equipping teams with the digital capabilities needed to strengthen operational excellence and maximize long term asset performance. She looks forward to continued collaboration with industry partners as data and digital technologies play an increasingly important role in the clean energy transition.
