"Customers Don't Buy a Battery — They Get an Energy Asset": Oskari Jaakkola, CEO of Cactos

Finnish company Cactos — a pioneer in smart energy storage — develops, manufactures, and leases intelligent energy storage systems that stabilize the grid, shave peak loads, and accelerate the rollout of renewable energy. Founded in 2021, the company already has over 100 professionals across offices in Helsinki, Kempele, and Amsterdam.

Cactos is a member of Energy Club — Ukraine’s professional energy business community dedicated to bringing world-class expertise and cutting-edge technologies to the Ukrainian market. In an interview with the Energy Club media department, Cactos co-founder and CEO Oskari Jaakkola explained how intelligent energy storage systems can enhance grid resilience, optimize business costs, and unlock new revenue streams. He shared the company’s experience operating in Ukraine during the war, outlined the advantages of the Energy Storage as a Service model, and described the approach to partnering with Ukrainian EPC contractors and integrators. The expert also identified the key mistakes companies make when deploying BESS.

Cactos is a Finnish manufacturer of intelligent energy storage systems covering the full technology cycle, — said Oskari Jaakkola. — We design and control the entire technical stack of the system rather than just assembling components. Our systems combine proprietary hardware architecture, embedded control systems and cloud-based energy optimisation software. This full integration is what makes the system “smart.”

— Oskari, what exactly makes your software and hardware integration so unique in a market flooded with cheaper Asian alternatives? What is the core technological advantage of Cactos?

— On the hardware side, we design our own DC block architecture, battery management systems (BMS) and embedded energy management systems (EMS). This gives us flexibility in choosing battery cells and power electronics while maintaining tight control over system behaviour and safety.

On the software side, our platform Cactos Spine continuously optimizes how the battery operates. It forecasts energy demand, electricity prices and flexibility markets, and then automatically decides how the system should be used, whether for peak shaving, energy arbitrage, or grid services. It can also prepare for blackouts, maintaining a desired minimum state of charge for reserve power purposes.

Because we control both the hardware and the software, we can optimize performance at the system level rather than at the component level. This improves reliability, reduces integration costs, and allows us to continuously improve the system through data collected from our operating fleet.

In practice, this means that customers do not simply buy a battery, they get an intelligent energy asset that actively manages energy costs and grid interaction.

— Cactos already has an operational footprint in Ukraine, including a project with DTEK. Could you share your experience? What specific grid challenges did you encounter, and how did your system handle them under wartime conditions?

— Ukraine presents one of the most challenging energy environments in Europe today. The grid is under significant stress due to Russia’s continuous attacks on infrastructure, supply disruptions and rapidly changing demand patterns.

Our experience in Ukraine has highlighted the importance of flexibility and autonomous control in energy systems. In conditions where grid stability can change quickly, energy storage must be able to respond immediately and reliably.

The advantage of our system is that it operates with local embedded control combined with cloud optimization. This means that even if communication to external systems is temporarily disrupted, the battery can still operate safely and continue supporting the site.

Another key challenge in Ukraine is grid volatility and power quality issues. Storage systems must be able to manage rapid fluctuations in voltage and frequency while protecting the industrial processes connected to the grid.

Energy storage therefore plays a critical role not only in cost optimization but also in energy resilience.

— High CAPEX is currently the biggest hurdle for Ukrainian industrial consumers wanting to install BESS. Are you planning to introduce an Energy Storage as a Service (ESaaS) or leasing model in Ukraine? How does this financial model work for B2B clients?

— High upfront investment is indeed one of the biggest barriers for industrial customers considering energy storage.

For this reason, Cactos has developed a financial model where the battery system can be delivered through an operating lease or service model rather than a traditional purchase.

Under this model, the customer does not need to make a large capital investment. Instead, they pay a monthly fee for the use of the storage system while we retain ownership and manage the asset.

This model works particularly well in the B2B sector because it aligns incentives:

• the customer benefits from lower electricity costs and improved energy reliability;
• Cactos operates and optimizes the system to ensure maximum performance and uptime;
• the financial structure allows customers to adopt energy storage without tying up capital.

In many cases, the savings generated by the system through peak shaving and energy optimization help offset the monthly cost of the service.

For markets like Ukraine, where capital constraints are often significant, such Energy Storage as a Service models can accelerate adoption significantly.

— Ukraine has recently introduced new state-backed incentives for energy storage, including 5-year contracts for ancillary services with payments fixed in Euros. How does the Cactos proprietary software help asset owners maximize their ROI by automatically balancing between self-consumption, grid stabilization, and energy arbitrage on the Day-Ahead Market?

— Energy storage systems generate value through multiple revenue streams. These typically include:

• peak shaving and load optimization;
• energy arbitrage in wholesale electricity markets;
• participation in ancillary services;
• demand response services.

The key challenge is that these revenue streams change continuously depending on electricity prices, grid conditions, local requirements and market rules. This is where software becomes critical.

Cactos Spine continuously analyzes electricity prices, consumption patterns, market signals, battery state of charge and system constraints. Based on these inputs, the software automatically decides how the battery should operate in each moment to maximize value.

For example, the system may choose to charge during periods of low prices, discharge during high demand, or reserve capacity for ancillary services depending on which option produces the highest return.

Because this optimization happens automatically and continuously, asset owners can capture multiple value streams simultaneously without manual intervention.

— Cactos offers full turnkey (EPC) projects. What is your partnership strategy for Ukraine, and what kind of partners are you currently seeking?

— Entering a dynamic market like Ukraine requires strong local execution capability.

While Cactos designs the system architecture, software platform and core control systems, we believe that successful market entry requires collaboration with local partners.

In practice, this means working with local EPC contractors, electrical engineering companies, project developers and local utilities. Local partners bring valuable expertise in permitting, construction and regulatory processes.

Our role is typically to provide the technology platform, system design and operational optimization, while the physical project execution can be carried out together with experienced local partners.

We are particularly interested in partnerships with organizations that have strong capabilities in:

• BESS installation;
• renewable energy integration;
• industrial energy systems.

— Many Ukrainian factories and agricultural enterprises are currently installing solar panels combined with BESS to survive blackouts. From your European experience, what are the top 3 hidden risks or mistakes business owners make when choosing and scaling a Battery Energy Storage System?

— From our experience in Europe, there are several common mistakes that businesses make when deploying battery energy storage systems.

1. Choosing hardware without considering software capabilities. A battery is not just a physical device, it is an operational energy asset. Without advanced control software, it is difficult to capture the full economic value of the system.

2. Underestimating integration with existing energy systems. Many facilities already have solar power, generators, or complex load profiles. If the battery is not properly integrated with these systems, the expected benefits may not materialize.

3. Designing the system for today’s market rather than tomorrow’s. Energy markets evolve rapidly. A system that is optimized only for current conditions may not remain competitive in a few years. For this reason, it is important to select systems that are flexible, software-driven and capable of adapting to new market opportunities.

Energy storage should be viewed as a long-term energy platform rather than a single-purpose device.

The experience of Cactos demonstrates that modern energy storage systems have already moved well beyond the role of backup power. The combination of hardware solutions, intelligent software, and new financial models makes it possible to transform BESS into a comprehensive tool for enhancing business energy resilience and grid stability. For Ukraine — rebuilding and modernizing its energy system under wartime conditions — such technologies may become a key element of a new energy architecture: more flexible, more decentralized, and more deeply integrated with European markets.