Cactos

Cactos (Cactos Oy) is a Finnish energy technology company that designs, manufactures and operates battery energy storage systems (BESS) for commercial, industrial and grid-scale use. Its product range spans indoor units (Cardo, 130 kWh with backup power; Fero, 240 kWh), outdoor units (Steno, 240 kWh; Yavia, 430 kWh; Mylo, 520 kWh liquid-cooled) and the grid-scale Nevado line, available in three versions from 4,180 kWh / 2,090 kVA up to 9,196 kWh / 4,390 kVA, which can be combined to reach roughly 50 MWh of capacity. All systems use LiFePO4 battery modules with the in-house Cactos BMS and a rated cycle life of 8,000 cycles to 70% state of health. Units are managed by Cactos Spine, an in-house cloud service that collects real-time data on consumption, electricity prices and weather to schedule charging and discharging.

The systems address load shifting to cheaper hours, reduction of demand charges, peak shaving, virtual expansion of grid connection capacity, storage of on-site solar or wind generation, backup power during outages, and automated participation in reserve, ancillary service and wholesale electricity markets (day-ahead and intraday trading). Target sectors include manufacturing, logistics and transportation, EV charging, agriculture and greenhouses, real estate investors and other commercial and public properties. Named customers include Bloks Oy, taxi operator Menevä, logistics company Logitri, Rando Grid and Oulun Baari. Beyond hardware, Cactos operates as an energy company selling electricity directly to customers and trades storage capacity in electricity markets; it also finances the majority of the storage systems it deploys.

Early systems, with a capacity of 100 kWh, were built from recycled Tesla electric vehicle batteries sourced from countries including Norway and Sweden. Manufacturing and R&D began in Muhos in Northern Ostrobothnia and moved to a larger factory in Kempele in autumn 2024, where the company now builds systems and battery modules in-house.

Founding story

Cactos was founded in 2021 in Northern Ostrobothnia, Finland, by a team of energy and software experts; the idea originated in Muhos, which remained the R&D and manufacturing base until the move to Kempele. Oskari Jaakkola is CEO and a founder. The name derives from the cactus, which adapts to its environment and stores water and nutrients, with an Ancient Greek inflection.

Business model

Cactos sells and delivers battery energy storage as a service: customers receive the hardware together with the Cactos Spine cloud service, 24/7 monitoring and control, and all maintenance and updates, and retain 90–92% of net profits earned in ancillary service markets. Cactos finances the majority of its energy storage systems itself, and also acts as an energy company selling electricity directly to customers and operating, optimizing and trading storage assets on behalf of clients, as in its 34 MW / 89 MWh five-site Finnish mandate.

Revenue comes from delivery of battery energy storage systems (including multimillion-euro contracts and grid-scale portfolios), the Cactos Spine service with maintenance and monitoring, retail electricity sales to customers, and energy trading and ancillary service market participation, with customers receiving 90–92% of ancillary market net profits. Reported revenue was €17 million, following statements that revenue quadrupled for a second consecutive year.

Traction

More than 300 installed commercial and industrial battery energy storage systems and deliveries to over 400 sites across four countries, with installed capacity exceeding 100 MWh and a largest single installed system of 14.2 MWh. Revenue of €17 million and more than 100 employees were reported in June 2026, alongside an order book exceeding €30 million and statements that revenue quadrupled for a second consecutive year. The largest contract to date covers a 34 MW / 89 MWh portfolio across five Finnish sites.

Latest developments

In June 2026 Cactos raised €12.5 million with new investors Tesi, Hyundai Motor Group, Silence VC and FJ Labs and returning investors Union Square Ventures, JTel Oy and Rando Ventures Oy, to fund European expansion and its energy trading business. Days earlier it announced its largest contract to date, a multimillion-euro mandate to deliver, operate, optimize and trade a 34 MW / 89 MWh battery portfolio across five Finnish sites, and in June 2026 it participated in Finland's first congestion management flexibility market. In August 2026 it announced entry into Sweden's ancillary service markets.