Yassen D. Spassov

Principal Associate

Head of climate, energy and environment 

Yassen is an energy and environmental protection senior lawyer and works in several regulated industries. He is committed to the transition to a net-zero emissions economy.

Yassen Spassov


Yassen leads the Climate, Energy and Environment Practice of Eversheds Sutherland in Bulgaria.

He has been practicing the legal profession for over 12 years advising multinational companies, foreign investors, and their local subsidiaries in Bulgaria on matters related to energy and environmental law. Most of his work and attention have been dedicated to the development, acquisition, and/ or financing of renewable energy power projects (wind and solar power), regulatory advice, legal compliance, and various legal assessments for thermal power plants.

Electricity and natural gas trading form another major aspect of Yassen’s profile. He provides comprehensive legal advice and represents clients in negotiations and transaction work with a particular focus on spot and forward energy commodity contracts.

As regards power generation, Yassen has gained a hands-on experience in legal compliance at one of the largest coal power plants in Bulgaria. In 2016, he worked as a senior legal counsel and provided legal support to the senior management of the power plant and plant operator.

Yassen can also advise you on the full spectrum of regulations for hydrocarbon projects and infrastructure. Ranging from prospecting and exploration of natural resources to the EU third-party access rights and exemptions for transmission pipelines, Yassen has advised clients on onshore and offshore exploration and cross-border transmission projects.

In the area of environmental protection, the analysis of relevant aspects and implications for M&A and financing transactions top up Yassen’s line of service. He has an in-depth knowledge of environmental and climate change regulations including environmental authorizations (impact assessments, EIAs), waste management, water regulations and use of waters, soil protection, and various liability regimes for contamination/ pollution.

Yassen also helps clients with the drafting of transaction documents under the EU Emissions Trading System (EU ETS), including spot and forward agreements for trading in AAUs, EUA allowances/ CER credits.

As many companies now seek to limit their exposure to regulatory and transition risks, clients more frequently require the provision of strategic advice and planning for climate-related risks, or related ESG matters. This is where Yassen’s diverse energy, environment and climate change experiences become most indispensable. He actively monitors the implementation of the European Green Deal and the impact the EU policy has on global financial flows and supply chains.

In terms of client portfolio, Yassen has acted for companies from the US, UK, Europe, China, and Japan. These operate across a number of sectors including the power generation industry, natural gas exploration and extraction, transmission and distribution of electricity and natural gas, financial institutions, and consumer product manufacturing, distribution and retail operators.

Yassen has published various assessments of energy and environmental regulations in international legal journals and received recognition by highly reputable peers and publishers, such as the International Bar Association (IBA) and Oxford University Press (OUP).

In his spare time, Yassen enjoys travel, writing and longboarding.

Professional Activities

  • Member of the Sofia Bar Association since 2012
  • Junior lawyer, January 2012 – January 2014
  • Lawyer with full scope of legal practitioner rights and competence since January 2014

Awards and Rankings

  • ÖAD Scholarship for research on WTO/ EC relationship at the University of Graz, 2007
  • The Balkan Challenge Case (BCC) – a law moot court in Vienna, Austria: Winner – 1st place, 2007
  • Danish Governmental Scholarship awarded by the Danish Ministry of Science in 2006


Speaking engagements further complement Yassen’s professional background as he was invited to speak before several international audiences across Europe. His presentations featured various topics of interest including clean energy, protection of energy investments, electricity market structure and regulations.

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