Holtrop S.L.P. blog


Piet Holtrop is an international lawyer with more than 20 years' experience, the last 17 of which have been spent advising in the renewable energy sector in Spain. After more than 5 years defending the interests of thousands of renewable energy producers against the cutbacks introduced by successive national governments, Piet Holtrop has become a leader in the sector, participating in the public debate via his blog "Bruselas, Luxemburgo o Madrid" on energíasrenovables.com, the blog "La energía como Derecho" ("Energy as a Right") published in 20minutos.com, and writing as a member of the Club of Experts for energynews.com and movilidadeléctrica.com (the latter being a the leading Spanish institution for the development of the electric car). He also publishes regularly on the websites of Fundación Renovables ('Renewables Foundation'), El Periódico de la Energía ('The Energy Newspaper') and other publications. He is a committed defender of the need to change the current energy model, something that he considers urgent in the short-term and inevitable in the long-term.

Piet Holtrop is an active participant in the sector organizations APPA, UNEF, AEDIVE, the Platform for a New Energy Model (PX1NME), Secartys, the Energy Efficiency Cluster of Catalonia, the Winemaking Cluster of Catalonia, and the Biomass Cluster of Catalonia. He is a regular speaker in events and conferences organized by these organizations, and provides his legal opinion to the Legal Working Group of APPA and the PPA Working Group of UNEF.

He has defended and promoted petitions regarding self-consumption and the payment system for renewable energies before the Petitions Commission at the European Parliament. He meets regularly with European Commission public servants with respect to almost a dozen claims brought by our firm, which has resulted in detailed correspondence between the European Commission and the Spanish Government. Furthermore, he represents APPA and PX1NME in national and international tribunals on a Pro Bono basis.

With Dutch origins and raised in Germany, Piet Holtrop is fluent in Dutch, English, German, Spanish, Catalan and Friesian; he can also defend himself in French. These skills have allowed Piet Holtrop to provide advice in a wide variety of international transactions. He studied International Law at the University of Groningen before working firstly as an in-house lawyer in the financial sector with the Dutch merchant bank Kempen & Co, latterly moving into the Spanish jurisdiction with the Catalan firm JAUSAS, prior to finally founding HOLTROP S.L.P. Transaction & Business Law in 2008.
Piet Holtrop carries the transactional spirit in his DNA. He is an expert in M&A and has advised in over 1.000 MW of photovoltaic and hundreds of MW in wind power transactions. He is a point of reference in everything that concerns the regulation and legality of renewable energies, energy efficiency, smart cities and the energy transition more generally.

His firm was awarded the Eurosolar Prize in 2015 for its untiring defense of renewable energies.


As a food technology engineer, Maria Ferrer brings to the firm technical consulting experience with respect to the renewables and winemaking sectors. She has broad experience in the Agri-Food industry, collaborates in the M&A transactions we work on and advises on technical questions that impact on the sector’s regulation. The defense and promotion of sustainability is the fundamental basis upon which she carries out her work.

Maria represents our firm in the ‘Cluster INNOVI de Cataluña’, where she focuses specifically on the role of the energy transition in the winemaking industry.

Maria is bilingual in Spanish and Catalan and fluent in English. She graduated as a biologist from the University of Valencia and holds a Masters in food technology from the Polytechnic University of Valencia. Maria is a co-founder and director of our firm.

Maria has also worked for 10 years as a permanent professor of Process and Quality in the Food Industry.


Natalia Escánez Comino is a lawyer with more than 16 years’ experience. She has a proven track record in the profession, particularly with respect to litigation in the ordinary jurisdiction before civil and commercial courts, and the administrative jurisdiction before relevant tribunals, as well as having a profound background in arbitration. In our firm Natalia takes charge of our civil litigation and contentious administrative law matters. She has extensive experience advising industrial and commercial clients in both regulated and non-regulated sectors including, for example, digital and financial entities.

She is a key contributor to the APPA Legal Working Group, advising with respect to litigation in the regulation of the electrical sector. Natalia, who speaks fluent Catalan, Spanish and English, graduated as a lawyer from the University of Barcelona. She also holds a Masters in International Legal Practices from the ISDE Law & Business School.

Natalia commenced her legal career in 2002 in the law firm Jausas, where she worked for five years. She has also worked for Riba Vidal, NEC and Gómez-Acebo & Pombo. Natalia brings with her an outstanding knowledge of procedural law and norms, something that has provided her with the ability to guarantee her clients an outstanding level of service both with respect to matters in litigation and case management strategy.


Abel Garriga is an of counsel lawyer with our firm. He has more than 20 years’ experience as a lawyer, primarily working in civil and commercial law. His particular expertise is in intellectual property and the regulation of new technology, having a profound knowledge of the legal issues associated with telecommunications and the internet.

Abel has worked as a lawyer since 1995. He is a specialist in author rights and industrial and intellectual property, and advises companies and cultural institutions that use intangible goods for commercial and cultural purposes. His clients include, for example, producers, publishers and advertising agencies, as well as museums, foundations and authors. As a result of the popularization of IT and communications technology, Abel’s practice centers on the articulation of possibilities that allow for the innovative use of digital technologies within the current legal framework. He prepared the first ‘copyleft’ license adapted to the Spanish legal system and participates in Creative Commons. Abel combines his professional activity with teaching and conference participation. He is also a member of the Literary and Artistic Association for the Defense of Author’s Rights.

Abel is fluent in Catalan, Spanish and French and graduated as a lawyer from the University of Barcelona.

As an expert in civil, commercial and international law, Abel advises our clients with respect to patents, trademarks, commercial litigation, copyright, telecommunications and international M&A transactions.


Jose Manuel Pérez Marzabal has more than 20 years’ experience in advising clients with respect to legal and business issues associated with information technology, electronic commerce, applications and electronic platforms. He has participated as a speaker and expert in numerous conferences and events related to online business, technology and E-commerce organized by Barcelona Activa, the Barcelona Bar Association, Recoletos (Madrid), the International Bar Association, the Catalan Consumer Agency, the Castellón Chamber of Industrial Commerce and Navigation, the Génova Financial Club (Madrid), ‘Mundo Internet 2002’ (Madrid), the Digital Health Venture Forum (Valencia) and BioLinx Finance Academy (Goteburg).

J.M. Pérez Marzabal has an extensive academic track record, having worked as a teacher and researcher in research institutions such as the Centre for Commercial and Law Studies in London, Queen Mary Westfield College, the Centre for Research in European, Economic, Financial and Tax Law in Lisbon, La Salle University Ramon Llull, ESADE, IL3 at the University of Barcelona and the Autonomous University of Madrid. He has figured as a specialist in various media outlets, such as RAC1, Galicia Television, TEDXGalicia, amongst others, and has published extensively in the press at both national and international level. Examples of such publications include ‘Cinco Días’, BNA – Electronic Commerce and Law Report, Aspatore Books and the Electronic Contracting Magazine.

Originally from Barcelona and with a distinguished track-record internationally, J.M. Pérez Marzabal speaks fluent Spanish, Catalan, English, German and Portuguese. This has allowed him to advise on a wide array of transactions and projects with international clients. He has also worked in-house with Grupo Mecalux and was the Director of the IT and Communication Law department of the Catalan firm JAUSAS. Jose Manuel currently works with HOLTROP S.L.P. Transaction & Business Law in his capacity as Of Counsel.

In his professional experience he has worked on different projects related to the legal aspects of electronic commerce, applications and electronic contracting, electronic communications, intellectual and industrial property, contracts related to the Internet and social networks, compliance and data protection, venture capital funds, and national and international startups.

J.M. Pérez Marzabal received his undergraduate degree from the University of Barcelona and completed a Master of Laws (Magister Legum) in International Law at Westfälische Wilhelms-Universität Münster (magna cum laude). He has also received a Postgraduate qualification in Intellectual and Industrial Property Law from ESADE and completed the Development of Telecommunications, Multimedia and Internet Law Program at the IE Instituto de Empresa (Madrid). He is currently studying a PhD in Law and Economics from the University of Barcelona.


Jorge Andrey Sterner is a lawyer whose specialties are renewable energies, climate change and the energy transition. In our legal consulting working group, Jorge advises on legislation and business models based on renewable energy, such as self-consumption and the electric car. Jorge has advised public entities regarding the promotion of energy transition and climate change policies. He participates along with other members of the firm in the UNEF self-consumption and PPA working groups, and also provides support to APPA’s legal working group.

He plays an active role in the preparation of substantive litigation that the firm handles in the name of thousands of renewable energy producers. He forms part of our corporate communication team, informing our clients on the progress of their cases as well as maintaining sections of our blog.

Also, Jorge frequently works alongside our M&A team regarding regulatory questions, for example in the preparation of litigation clauses in contracts and the assignment of credit rights derived from litigation.

Jorge’s mother tongue is Spanish and he is professionally fluent in German and English along with a working knowledge of French and Catalan. After graduating with a double degree in law and political sciences from the Autonomous University of Madrid, he expanded his technical knowledge of the sector through undertaking the course Technology, Implementation and Profitability of Renewable Energies at the Fernshule Weber school, completing his studies with a masters degree in Politics and Environmental Planning at the Technical University of Berlin.

His career has been closely linked to renewable energies and sustainability for years. After completing an internship in public contracting at the Tres Cantos Council (Madrid) he moved to Berlin, where he worked for a number of years for companies dedicated to the development of renewable energy projects at an international level.


Loida Gil Mena holds a degree in law from the University of Barcelona and is currently studying her Masters in legal practice at the Catalan Open University. In our firm Loida participates in the litigation team on a wide array of matters, whether they be civil litigation, bankruptcies or administrative proceedings. She also frequently assists our M&A team in the preparation of Due Diligence reports.

Loida speaks perfect Spanish, Catalan and English, and has a working knowledge of French. As part of her studies she spent a year in the United States at Columbia University, New York, where she obtained a Certificate in International Business Law.

Prior to commencing with our firm Loida completed a year-long internship at the law firm Codina & Roig Associates.




Cristina López Rodríguez is the head of our accounting team, as well as taking charge of our communications with clients. She oversees the contracting of providers, the invoicing processes and other tasks that are vital for the correct functioning of our professional activities.

Cristina speaks Spanish, Catalan and English. She graduated from the Center of Financial Studies as an accounting professional and subsequently undertook further studies at IOC and Acedis, obtaining superior qualifications in administration, finance and IRPF as a result.

Prior to joining our firm, Cristina worked as a bookkeeper for more than 12 years in a wide variety of companies, including a number of law firms.



Esteban Carrillo Varga is our firm’s IT and administrative expert. He is responsible for coordinating our databases and protecting our IT system. Esteban assists our accounting team and is responsible for managing the details of thousands of clients in the litigation that our firm runs with respect to cuts in the electricity sector. He coordinates the expert opinions that we solicit as part of this litigation, as well as managing an external team of professionals who provide technical, IT and web services.

Esteban has undertaken professional studies in metallurgy and as a sound technician. He is currently studying towards a professional business accounting qualification.