Key TNEI contacts

Nilanga Jayawarna

Operations Director

Nilanga Jayawarna

Nilanga is the Operations Director of TNEI Services Ltd. She is an Electrical Engineer who is based in our Manchester office and has a broad range of experience in people and project management, power system studies and grid code compliance.

Nilanga gained her BSc (Hons) in Engineering from University of Moratuwa in Sri Lanka and her PhD from University of Manchester. She worked as a Post-Doctoral Research Associate at University of Manchester for four years before joining TNEI.

She joined TNEI in 2009 as a Technical Consultant and took the Operations Manager role in 2014 leading to being appointed as the Operations Director in 2016. She enjoys the daily operational challenges of leading a team of 50+ consultants whilst still being involved in the varied technically challenging projects as a project director. Nilanga has 17 years of experience in the power industry including the time she spent on her PhD on Microgrids. At TNEI she has been predominantly working on onshore renewable projects.

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Nigel Tate

Commercial Director

Nigel has been a Director of TNEI for approaching 20 years and has seen the business develop significantly during that time.  He became full time with TNEI in 2007 having previously also been a Director of the UMITEK specialist consultancy and testing group that included Capcis and SREL – both successful companies in the energy sector. He is a Chartered Management Accountant by profession and is responsible for all the financial and contractual aspects of the business in addition to using his experience of managing small, specialist consultancy companies as part of the TNEI management team.


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James Mackay

Head of Technical Services

James Mackay

James manages the Site Services team, which provides a range of services including noise assessment, GIS / CAD mapping, shadow flicker assessments and soil resistivity measurements.

Since joining TNEI in 2006, James has developed a detailed knowledge of wind farm noise assessments and has worked on over 4 GW of onshore wind projects from initial site finding and feasibility assessment through to post construction compliance monitoring and complaints investigation. In 2013/2014 James was involved in the drafting of Good Practice Guidance for wind farm noise assessment for the Institute of Acoustics (IOA GPG). 

The nine strong Site Services team has provided expert witness services in relation to wind farm noise at over 30 Public Inquiries and wider technical support for projects in the renewable energy, transmission and distribution, oil and gas, residential and industrial sectors.

James is the main contact for noise assessments, expert witness services, GIS / CAD mapping and shadow flicker assessments.

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James Hollender

Developer Support Lead

James is a Chartered Civil Engineer with over 14 years’ experience in the power sector having been involved in the assessment, design and construction of over 3GW of projects. Since 2004 James’ work has focussed on renewable energy and power including onshore and offshore wind, solar, STOR, transmission and distribution and battery storage projects. He has worked on site as Owner's Engineer, Bank's Technical Advisor and Principal Contractor. James is a Certified Member of the Association for Project Safety and has successfully discharged the CDM roles of Planning Supervisor, CDM-Coordinator and Principal Designer on several projects.

James leads the developer support team which provides clients with the advice and support needed to take their project from conception through to construction.

Skills within the team include Environmental expertise, Town Planning, EIA, GIS, Grid Connections, Electrical engineering , Civil Engineering and health and safety advice.

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Johan Smith

TNEI Africa Lead

Johan Smith is a senior consultant with over 10 years of experience in power systems analysis. His experience includes transmission and distribution system modelling, network planning and feasibility of integrating power plants into electrical grids, HVAC/HVDC interconnections and grid code compliance. During his career Johan has developed system models for electrical power networks both in Africa and internationally.

Since 2012, he has been performing steady state and dynamic grid integration and compliance studies for independent power producer renewable energy projects. His experience includes interconnected systems as well as mini grids and the influence of Variable Renewable technologies. He holds a M.Tech degree in Electrical Engineering and is professionally registered with the Engineering Council of South Africa.

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Charlotte Higgins

Network and Innovation Team Co-Lead

Charlotte has an extensive background in the energy sector with over 19 years of experience in the field of systems analysis, particularly in power systems applications. A particular strength of Charlotte's is her ability to provide specialist knowledge to cross function projects where a wide range of stakeholders need to be consulted and their requirements balanced to find the best technical and commercial solution. She has expertise in technical, economic and regulatory considerations for the development of transmission and distribution networks including integration of renewable generation, smart grids, HVDC systems and low carbon technology. 

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Chris Ellis

Connections Lead

Chris manages the Connections team and is based at the TNEI Manchester site. He has an extensive background in the energy sector with over 24 years of experience in project management, power system studies, grid code compliance, power system and substation design, protection and control, electrical applications and verification whilst working at Areva T&D/Alstom Grid, ABB, London Power Associates and Atkins.

His experience includes team management and the delivery of complex multi-discipline worldwide technical projects in transmission and distribution planning, design and analysis, HVDC design, AC/DC protection and system studies, substation design, cable assessments, cost benefit analysis and EMC compliance.

More recently Chris managed the power system team within Atkins which involved the design and verification of the first UK floating offshore wind farm, data centre design and verification and protection design for large power station projects in the UK and in Europe.

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Stephanie Hay

Network and Innovation Co-Lead

Stephanie is a Principal Consultant and Networks & Innovation Team Lead for TNEI’s Scottish office in Glasgow. She has 11 years of experience in the power industry including a 4-year PhD on active network management and control of distribution networks and 7 years as a power system consultant. She has significant experience in electrical system studies, analysis and software packages.  

She is practiced in undertaking grid connection studies for network planning and impact assessments on networks ranging from large trans-continental transmission systems to small island distribution networks. 

Stephanie’s main focus in recent years has been providing technical and market expertise on emerging technologies and delivering concept, innovation and strategy projects for large industry organisations, including several studies for Scottish Enterprise on MVDC, Energy Systems, Niche Transport Applications and Green Hydrogen. This expertise drives the development of the work and the team in Scotland such that TNEI are well-placed to support the ambitions of the energy industry.

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Dieter Gütschow

International Lead

Dieter recently joined TNEI in Manchester as a Specialist Consultant in the Networks and Innovation division. He has more than 20 years of electrical engineering-, international project management- and consulting experience in various areas of the electrical industry. This includes managing large wind farm construction projects, distribution network reliability modelling and planning, asset management, smart grid initiatives, and techno-economic feasibility studies for network expansion and renewable projects.

Dieter’s career started at Eskom, South Africa’s national power utility, where he was a chief engineer responsible for, amongst others, the telecommunications and SCADA systems of the distribution and transmission power networks.

Subsequently, as a consultant he led several assignments and teams on a wide range of subjects, the most notable of which was the development of an operational strategy for Eskom, the development of an asset management strategy, and a new planning and substation design standard to improve network reliability. Other assignments he managed include the development of a 30-year energy forecasting model for Transnet, the feasibility study and preliminary design of a 400kV transmission network in Tanzania, and the development of a smart metering pilot project in Cyprus.

More recently Dieter was a project manager for an EPC company responsible for the design, engineering, and construction of the electrical balance of plant, including 400/132 kV substations and 132kV power lines, for two large wind farms in South Africa.

Dieter has technical, management consulting, and project management experience in South Africa, Botswana, United Kingdom, Cyprus, Lithuania, the Netherlands and Germany.

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Jason McGray

Principal Consultant, Planning and Consenting

Jason McGray heads up TNEI's planning and consenting team. He is a Chartered Environmentalist,  full member of the Institute of Environmental Management and Assessment and a Registered EIA Practitioner. Jason has extensive experience of coordinating, preparing and reviewing Environmental Impact Assessments and in gaining planning consent for a range of energy related projects. In addition, Jason has undertaken environmental due diligence and provided specialist input into strategic and regulatory projects working alongside TNEI's technical and engineering experts. He has supported complex projects for both private and public sector clients including Ofgem and the Crown Estate. 

Jason's wider experience includes detailed feasibility assessment, environmental permitting, socio-economic impact assessment, delivery of programmes of community engagement and financial modelling. 

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Jonathan Oguntona

Grid Connections Lead

Jonathan is a Senior Consultant and Grid Connections Lead with 10 years’ experience working as an electrical engineer and grid connection specialist. 

Jonathan has experience managing the design and delivery of grid connection work packages on both the distribution and transmission network for onshore wind, solar PV, large biomass and battery energy storage projects across the UK. Since he joined TNEI Jonathan has worked with and provided support to offshore wind and island wind developers.

He has also coordinated the delivery of Contestable Works for embedded generators. He has significant experience in power systems analysis specifically providing power quality grid compliance studies (P28 &Harmonics).

Jonathan has good communication skills and has provided technical, commercial and regulatory advice to clients. He has significant project management experience, and a pragmatic approach to problem solving.

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