Norsepower – Rotor sails driving the clean transition in maritime

Why?

Emissions from shipping account for about three per cent of global carbon dioxide emissions. Up to now, shipping has been one of the most difficult sectors to transition towards carbon neutrality. The tightening regulatory environment also poses significant challenges for the industry. Norsepower was born out of a desire to solve this unsustainable equation. The company’s product offers a practical, economically rational and immediately deployable solution for reducing both carbon dioxide emissions and fuel consumption.

The rotor sail developed by Norsepower incorporates the latest advanced materials, artificial intelligence and automation. From the outset, the company’s mission has been clear: to build a bridge towards zero-emission maritime transport – not in the next decade, but right now.

What and how?

Norsepower’s rotor sail is a renewed version of the old Flettner rotor. The rotating surface of the cylindrical sail, which is rotated by an electric motor, forms a force that pushes the vessel forward when it encounters the wind. Use of the ship’s own engine power can thus be reduced, generating up to 70% savings in fuel, depending on the ship, route and weather conditions. The electrical power requirement of the solution is minimal in relation to the benefits achieved.

The rotor sails are easy to install on the deck of existing ships and are designed to last even longer than the vessel itself. A sail produces more than 1,000 data streams per ship and optimises its performance with artificial intelligence in real time. The product has already clocked up over 500,000 hours of use. Rotor sails have saved more than 10,100 tonnes of fuel and reduced carbon dioxide emissions by over 31,700 tonnes.

Growth and internationalisation

Norsepower’s growth is driven in part by the product’s maturity and market readiness. Market entry of the product was due to product development, but on top of this the timing proved to be perfect. The company has switched from manufacturing individual sails to serial production, and now delivers its products globally. Norsepower opened the world’s first rotor sail factory in China, enabling serial production and rapid scaling of volumes. The company’s Helsinki headquarters are meanwhile developing software, AI-based control and sensor networks.

Norsepower operates in more than ten countries, with Japan now a particularly important market. The company’s production capacity for 2025 is almost sold out, bearing testimony to strong international interest in the product.

The importance of growth equity

Tesi became one of the company’s owners in 2021 as Norsepower was in the European Regional Development Fund’s (ERDF) investment portfolio, when it was transferred to Tesi as part of Finnvera’s venture capital operations. The Finnish Climate Fund (part of Tesi as of 31 May 2025*) also supported the company’s development. Private equity has been critical in transforming Norsepower from a start-up into an industrial player. Tesi’s role has not been limited to providing capital. It has also contributed strategic expertise, insights into board work, and valuable support in building international partnerships.

To support Norsepower’s growth, a crowdfunding round was also launched in spring 2025 through Springvest Corporation, an investment service company. Norsepower’s scaling requires continuous investment in production and personnel. Private equity investors help to manage this development in a systematic and efficient manner.

General information

Founded in 2012, Norsepower is a Finnish cleantech company that develops and manufactures rotor sails for ships. The company employs more than 130 people. Of these, about 80 experts from some 20 countries work at Norsepower’s Helsinki headquarters. The rotor sails are manufactured at the company’s factory in China. A global player, the company is now the market leader in its field and the only one with its own rotor sail factory. To date, Norsepower has delivered 37 rotor sails to 19 ships. The company currently has 50 new orders on its books. The product is at the heart of a rapidly expanding market worth some EUR 60 billion. The current global market encompasses around 30,000 vessels.