Cactos: From energy storing to a new age energy company

Cactos is a company that offers energy storage systems designed and made in Finland for the needs of industry and power grids. These systems make energy use cost-effective, support the functioning of the electricity system, and enable the energy transition. In just a few years, the team of seven founders has grown into an organization of over 100 people with a strong foothold in Europe. The direction is clear – Cactos wants to be a driving force in the energy transition.

In December 2021, seven friends gathered around the same table. They all shared a background in the oil industry, finance, and technology—as well as a sense that the energy transition was already underway. Electricity prices were fluctuating, consumption was growing, and the grid was lagging behind. This led to a realization: electricity must be stored and used wisely.

“The idea was simple, but its implementation required courage. We wanted to build a solution that would not only fix the shortcomings of the electricity system, but also move the entire energy market forward,” recalls Oskari Jaakkola, founder and CEO of Cactos.

Cactos was born in Northern Ostrobothnia, where the first systems were developed and built. The head office was later moved to Helsinki, but product development and production remained in their birthplace. From the beginning, Cactos wanted to do things differently. While others were building massive electricity storage facilities on the edges of fields, Cactos created a decentralized system and brought electricity storage directly to properties – to industry, logistics, and electric transport. This allowed energy to be balanced in the areas where it is used.

Drivers for growth

The first functional system was completed in the summer of 2022, and by August it was already serving its first commercial customer. The vision had become reality. Around the same time, Superhero Capital came on board. They were impressed by Cactos’s ready-made and functional processes.

“They had an exceptional team that was capable of handling the entire value chain – from batteries to software and electricity trading. It was a rare, complete package at such an early stage,” says Juha Ruohonen from Superhero Capital.

Superhero Capital’s investment enabled Cactos to recruit new staff, rapidly develop its software, and scale up its deliveries. Later, US-based Union Square Ventures also joined the story, giving Cactos access to international networks.

Cooperation with investors has been straightforward. The board provides sparring and communication is agile on a daily basis. “When you have an experienced team and good business, you don’t need excessive guidance. Our job is to support and open doors for them,” Ruohonen sums up.

Towards internationalization and new capacity

In 2023, Cactos launched a new battery model and growth accelerated further. The market was still nearly empty, and demand was high. Over time, the number of employees grew from the founding team to over a hundred, and at the same time, turnover multiplied by four. The last financial year ended with a turnover of over €12 million and a positive operating margin.

New systems were introduced in Sweden and the Netherlands, and in the fall of 2024, the company moved to new, larger premises in Kempele. The factory is the heart of the company: it is where modern automation and Finnish manufacturing meet.

In Ukraine, in the midst of war, Cactos’s storage facilities became vital: they served as a backup power source at the heart of the crisis and enabled the supply of electricity when the grid was under constant threat. “It has been particularly meaningful to see that our technology can help not only in business but also in difficult humanitarian situations,” says Jaakkola.

As part of the business model, a dedicated infrastructure fund was also established to finance customers’ electricity storage facilities. The model turns storage into a service: with a single contract, the customer gets the equipment, software, maintenance, and financing. The fund operates within the EU’s sustainable finance regulatory framework, and, for example, the carbon intensity of the electricity sold is reported transparently

A pioneer in the energy sector

Cactos became an electricity company at the beginning of October 2025 when it began supplying electricity to its industrial electricity storage customers. Electricity sales are a key part of Cactos’ vision for the future: the relative share of electricity in global energy consumption will grow at the expense of fuels and gas. The dominant position of traditional international oil companies in the global energy market will inevitably weaken and be replaced. Cactos believes that international electricity companies will rise to fill this gap, and Cactos aims to be a pioneer – a new era of technology-based energy companies.

What makes Cactos special is that they do everything themselves. The battery modules are manufactured in Kempele, the in-house developed software controls the warehouses from the cloud, and trading is carried out using their own tools under Cactos’ balance sheet responsibility – financing is also provided from their own fund. This reduces dependence on external suppliers and ensures cost and delivery reliability. For customers, this translates into cheaper electricity, more reliable capacity, and ease of use.

Today, Cactos is Finland’s largest electricity storage company — but the journey is only just beginning. Growth will be pursued both organically and, if necessary, through acquisitions, though often the best solutions are developed in-house. With the entire chain, from equipment to software, under its own control, the possibilities are endless.

“We are building a company that will stand the test of time. We want to be the energy company of the new era – one that masters electrical energy,” Jaakkola sums up.

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This article is part of the Finnish Venture Capital Association’s and PwC’s Building Growth Competition 2025 blog series, where we present the stories of the competition finalists. You can find more information about the competition on our website. The final will be held at FVCA’s main event of the year, the Finnish PE-VC Summit, on October 9, 2025.