Joel Aartolahti

Associate, Member of the Finnish Bar

Services

  1. Environment, Energy & Green Transition

Contact details

I advise our clients in matters related to the environment, infrastructure and natural resources.

Before joining Castrén & Snellman I worked as a lawyer at another law firm and concentrated on real estate and construction related matters. Before my graduation I worked as a trainee in the real estate and environment team of another major law firm.

I graduated from the University of Helsinki in 2021. In addition, I studied energy and environmental law at the University of Aberdeen in Scotland for one semester.

Latest references

Downing – Acquisition of the entire share capital of Tornionlaakson Voima
We advised UK-based investment company Downing in its acquisition of the entire share capital of Tornionlaakson Voima Oy. Tornionlaakson Voima owns three hydropower plants in the Tengeliönjoki river system – the Portimokoski power plants in Ylitornio, the Jolmankoski power plants in Raanujärvi and the Kaaranneskoski power plants in Sirkkakoski. The power plants produce a total of approx. 45 gigawatt-hours of electricity per year. Tornionlaakson Voima’s daily operations will continue normally, and the transaction will not affect customers. The consummation of the transaction is subject to the approval of the Ministry of Economic Affairs and Employment. Downing has over 35 years’ experience in providing a wide range of investment solutions to the needs of institutional investors, advisers and retail investors. The company manages over £2 billion in assets in both the private and public markets and its current hydro power portfolio includes approx. 50 hydro power plants in the Nordics. 
Case published 27.3.2026
Merger of Oomi and Lumme Energia
We are acting as the joint legal advisor to Oomi Oy and Lumme Energia Oy in a transaction whereby Lumme Energia will merge with Oomi. As from the completion of the merger, the combined entity will be the largest electricity retail and service company in the Finnish market. In 2024, Oomi reported a turnover of EUR 373.9 million and had approximately 110 employees. Lumme Energia’s turnover for the same year was approximately EUR 314.6 million and it had approximately 50 employees. The transaction is primarily driven by the recent developments in the electricity market and the strategic goal to develop competitive products and services. Another key objective is to further enhance the customer experience, which is a shared value between the two companies. As a result of the merger, Lumme Energia’s customers will transfer to Oomi, and Lumme Energia will become one of Oomi’s shareholders. The completion of the transaction is subject to an approval by the Finnish Competition and Consumer Authority.
Case published 29.8.2025
Fortum – Acquisition of a project development portfolio for renewable power from Enersense
We are acting as a counsel to Fortum in a transaction in which Fortum is strengthening its renewable power project pipeline through the acquisition of a project development portfolio from Enersense. The debt-and-cash free purchase price is approximately EUR 9 million, with the potential for project-specific earn-outs subject to projects successfully reaching a final investment decision in the future. The transaction is subject to customary closing conditions and is expected to be completed during the first quarter of 2025. Fortum is a leading Nordic energy company with the purpose to power a world where people, businesses and nature thrive together. Fortum’s core operations comprise of efficient, CO2-free power generation as well as reliable supply of electricity and district heat to private and business customers. The company is listed on Nasdaq Helsinki. One of Fortum’s strategic targets is to develop at least 800 MW of ready-to-build onshore wind and solar projects by the end of 2026.
Case published 19.12.2024
Hanza AB – Acquisition of Leden Group
We acted as Finnish advisor to Hanza AB relating to its acquisition of all the shares in Leden Group Oy. Hanza AB is a Swedish mechanical engineering and electronics contract manufacturing company listed on the Stockholm Stock Exchange. Founded in 2008, the company has six manufacturing clusters in Sweden, Finland, Germany, Baltics, Central Europe and China and an annual turnover of approximately SEK 4.6 billion. Leden Group is a leading Finnish contract manufacturer specialising in sheet metal, machining and complex assembly. Leden Group has four production sites in Finland and one in Estonia and an annual turnover of approximately SEK 1.1 billion. 
Case published 13.12.2024
Fortum – Sale of recycling and waste business
We acted as the lead counsel to Fortum in a cross-border transaction in which Fortum sold its recycling and waste business. The business was sold to thematic impact investing firm Summa Equity through its portfolio company NG Group. The debt-free purchase price is approximately EUR 800 million.  Fortum’s recycling and waste business to be sold comprises municipal and industrial waste management and end-to-end plastics, metals, ash, slag and hazardous waste treatment and recycling services. These businesses are located in Finland, Sweden, Denmark and Norway and currently employ approximately 900 employees.
Case published 18.7.2024
G&W Electric – Acquisition of Safegrid
We advised G&W Electric with its acquisition of Safegrid Oy, a leading provider of intelligent grid monitoring solutions based in Finland. The acquisition accelerates G&W Electric’s long-term strategy to integrate intelligent monitoring and predictive analytics into its power distribution portfolio, strengthening its offering to utility customers worldwide. Founded in 1905 and headquartered in Bolingbrook, Illinois, G&W Electric is a global leader in innovative power grid solutions, with a presence in over 100 countries. The company is known for advanced load and fault interrupting switches, reclosers, sensors, system protection equipment, power grid automation, intelligent grid monitoring, and transmission and distribution cable accessories. Safegrid is a Finnish technology company headquartered in Espoo, Finland. The company develops the Intelligent Grid System®, a grid monitoring solution that combines instant-on wireless sensors with advanced analytics to deliver real-time insight into grid conditions, enabling utilities to identify emerging issues, anticipate failures, and reduce outage duration across medium and high voltage distribution and transmission networks.
Case published 8.5.2026
Kiwa – Acquisition of Sertio
We advised Kiwa in its acquisition of Sertio Oy, a Finnish notified body designated by the authority in accordance with the EU Regulation on in vitro diagnostic medical devices (IVDR). Sertio provides conformity assessment services in accordance with IVDR. Kiwa is one of the world’s leading testing, inspection, and certification companies, operating in over 35 countries. 
Case published 7.5.2026
Metsäkonepalvelu – Acquisition of Junnonen Forest and the business operations of Lamerit
We advised Metsäkonepalvelu Oy in its acquisition of the entire share capital of Junnonen Forest Oy, a Finnish timber harvesting services company, and the timber harvesting services business of Lamerit Oy. The acquisition supports Metsäkonepalvelu’s growth strategy and strengthens the company’s position, particularly in southeastern Finland. Metsäkonepalvelu is a portfolio company of A. Ahlström Oy, a Finnish family-owned industrial owner. The company provides mechanical timber harvesting services to forest companies, large private forest owners, and the public sector in Finland and Sweden. Metsäkonepalvelu Group employs nearly two hundred forestry professionals.
Case published 6.5.2026

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