Project Engineer – Delivery (Grid-Scale Battery Energy Storage)

Cactos is a driving force in the energy transition. Do you want to help build a future where energy is used smartly and sustainably? We are now looking for a Project Engineer who is ready to take responsibility for real, concrete project deliveries and help scale our grid-scale energy storage business.

Cactos in a nutshell

Cactos is a Finnish next-generation energy company transforming how industrial customers manage and consume electricity. We deliver smart battery energy storage systems, proprietary software, and electricity directly to customers – as one integrated solution.

Our systems stabilize the grid, smooth out peaks, and protect customers from price spikes and bottlenecks while unlocking the full potential of renewables. We manage every part of the process ourselves, from hardware to software, trading to financing.

Founded in 2021, Cactos now employs over 100 people across Helsinki, Kempele and Amsterdam. In 2025, Cactos was named Finland’s top growth company by PwC and the Finnish Venture Capital Association.
Read more about Cactos → cactos.com

The role

As a Project Engineer you will play a key role in delivering Cactos’ grid-scale battery energy storage projects from final design all the way to commercial operation.

This is above all a delivery-focused role. While you will support some project development work, your core responsibility is to make sure that projects are engineered, procured, installed, commissioned and handed over smoothly, on time and with high technical quality.

You will work closely with contractors, equipment suppliers, internal engineering teams, and customers. Our projects currently focus mainly on <10 MW and 20 kV DSO connections, but we are already moving towards larger projects up to 30–50 MW and 110 kV grid connections in the future.

The role is based in Helsinki or Kempele, with a hybrid setup combining office, remote and site work.

Key responsibilities

• Act as a technical project engineer in grid-scale BESS projects from engineering to commercial operation (COD).
• Coordinate and support engineering activities with internal teams and external partners.
• Manage and interface with contractors, equipment vendors and OEM partners.
• Support procurement activities related to equipment, installation and services.
• Participate in installation supervision, site visits and commissioning activities.
• Ensure projects meet technical, quality, safety and grid compliance requirements.
• Support selected project development and proposal engineering tasks when needed.

Background & requirements

• BSc or MSc in Electrical Engineering, Energy Technology, Automation, Civil Engineering or similar.
• Around 5+ years of relevant experience in project engineering / technical project delivery.
• Experience from energy, infrastructure, renewable energy, BESS, or related industrial projects.
• Experience working with contractors, suppliers, and multidisciplinary project teams.

• Experience in procurement, installation and commissioning phases.
• Willingness to travel to project sites when required.
• Fluent Finnish and English.

What we offer

• A key role in building Finland’s and Europe’s next-generation grid-scale energy storage infrastructure.
• Hands-on involvement in real, impactful energy transition projects.
• A growing, ambitious company with a strong mission and fast development.
• A hybrid working model combining office, remote and site work.