Garret is a partner and head of both Matheson’s Energy, Natural Resources and Utilities Group and Projects and Infrastructure Group. Garret is also a member of Matheson’s ESG Advisory Group.
He advises on all aspects of energy, natural resources, utilities and infrastructure projects and project financing, from PPPs to privately-financed electricity and gas developments and privatisations as well as electricity, gas and telecommunications network infrastructure.
Garret specialises in particular in the areas of electricity and gas market regulation and trading.
Garret’s experience also includes project development, M&A and financing in the conventional and renewable electricity sectors as well as the mining and upstream and downstream oil and gas sectors. Garret is also very active advising his international and domestic clients on ESG regulation in Ireland and across Europe.
Garret is consistently listed as one of Ireland’s leading Energy lawyers, including in leading legal international directories such as Legal 500, Chambers Europe and IFLR1000. He is a frequent speaker at energy and infrastructure conferences and regularly contributes articles to specialist publications.
Experience and Education
Energy, Natural Resources and Utilities
Some of Garret’s more recent experience highlights include advising:
- Sellers and purchasers (including PE, insurance, pension and infrastructure funds) on the sale and / or acquisition of major energy and infrastructure assets in recent years, including over 3GW of electricity generating assets (of which over 1.2GW are renewable generators), Ireland’s only oil refinery at Whitegate and Ireland’s largest oil storage terminal at Bantry Bay in County Cork.
- Advising on the sale and purchase of large portfolios of renewable energy assets.
- Sponsor and Lenders on the development and financing of over 2.5GW renewable and conventional power plants developments. This includes over 1.2GW of onshore wind farm developments since 2015.
- Sponsors on the permitting and development of offshore windfarms.
- A bidder on its due diligence of a 1GW+ renewable energy portfolio in Ireland, the UK and the EU which was sold by Brookfield.
- A listed renewable energy fund manager on its acquisition and project financing of a 250MW solar farm.
- Advised Equinor on its bid for a European offshore windfarm portfolio.
- Advising the sponsor on the development of a new energy park in the Irish midlands, which will include a data centre, wind farm, solar park and a battery storage project.
- Advising a State-backed investment fund on its funding of the acquisition of over 130MW of Irish wind generating facilities in advance of the first ever public listing of an Irish renewable energy investment vehicle on the Irish Stock Exchange.
- EirGrid and SONI on all aspects of the I-SEM project which is the new wholesale electricity market arrangement for Ireland and Northern Ireland. Matheson’s role involved drafting and advising on the new rules for the balancing market, the new capacity market code, the amended grid code, the new trading rules for the day ahead and intraday markets in I-SEM as well as drafting amendments to EirGrid’s operational agreements and licences necessitated by I-SEM.
- A bidder on its due diligence and bid for the 500MW Greenlink interconnector project between Ireland and the UK.
- A large international conglomerate on the development and financing of a 200MW Battery Energy Storage System project in the mid-west region of Ireland (this is the one of the largest projects of its kind in Europe).
- Advising on the development of large data centres in Ireland, and corporate power purchase agreements entered into relating to data centres.
- Advised a large European utility and developers on the development of large BESS projects and synchronous condensors in Ireland, including the M&A, financing and regulation of those projects.
- Advising on the vast majority of corporate PPAs entered into in Ireland to date, including a number of large multinational technology companies in relation to the drafting and negotiation of corporate power purchase agreements (including the first to be announced in the Irish market) and on their renewable energy procurement strategy and trading structures and agreements.
- Advised General Electric and GAMA on the sale of its 80% interest in a 400MW CCGT thermal power plant.
- Advising power and gas utilities on their sales contracts and regulatory issues in the Irish market, and more recently on their biomethane sale and purchase agreements.
- A large multinational company on the sale of an energy supply company in respect of a large Irish wind farm to an international technology company, including the negotiation of the first corporate PPA in the Irish market.
- Partners Group (UK) Limited, a global private equity firm, on its acquisition of an interest in the Greenlink Interconnector, a project to construct a 500MW subsea electricity interconnector between Ireland and Great Britain.
- Irving Oil on the acquisition of Tedcastles Oil Products Unlimited Company and its associated subsidiaries.
- Brookfield, the previous owner of one of the then largest Irish wind farm portfolios, on various matters in connection with the introduction of the new wholesale electricity market arrangement for Ireland and Northern Ireland (I-SEM), including the re-drafting and negotiation of all of its existing PPAs and the structuring, development and drafting of a complex trade facilitation agreement in the context of I-SEM.
- TRIG, a closed-ended investment fund, in relation to the Irish law aspects of its £300 million IPO, listing on the London Stock Exchange. This was the largest flotation of a dedicated UK-based renewable energy company and raised £300 million, which is being used to acquire a 276 MW portfolio of 18 operational wind and solar parks in Ireland, the UK and France, from Renewable Energy Systems Limited and InfraRed Capital Partners.
- One of the largest thermal generators in Ireland on a wide variety of matters, including interface with its lenders, trading agreements and a complex outsourcing agreement in respect of gas trading services.
- Two of the largest utilities in Ireland on their gas and electricity sale contracts.
- One of the leading global mining companies in relation to their Irish assets.
- Advised Vermilion on the acquisition of stakes in the Corrib gas field from Shell and Equinor.
Projects and Infrastructure
Some of Garret’s more recent experience highlights include advising:
- the ACS Group (including Iridium Concessions and Dragados) on transport infrastructure projects (including PPPs) in Ireland, including the majority of the toll road projects in Ireland.
- Bord na Mona on the development and project financing of (1) the 105MW Derrinlough wind farm project, (2) the 75MW Cloncreen windfarm and the adjacen Cloncreen battery storage project.
- International lenders to Irish PPP projects.
- The sponsor on the sale of its stake in 2 operational PPP projects.
- Exolum Aviación on all aspects of its successful tender for the design, build and operation of new aviation fuel terminal and pipeline infrastructure at Dublin Airport under a long term services concession agreement with airport operator daa plc.
- A large international conglomerate on the development and financing of a 200MW Battery Energy Storage System project in the mid-west region of Ireland (this is the one of the largest projects of its kind in Europe).
- the National Broadband Ireland project company (backed by Granahan McCourt investments and other investors) on its successful bid to design, finance, build and operate a high speed broadband network serving over 1 million people across Ireland (one of the most ambitious and wide-reaching State-backed broadband interventions in the world).
- Lenders to new large CCGT and OCGT power plants in Ireland (including recently Natwest and PGIM), which are required as part of the energy transition.
- Advising on the development of large data centres in Ireland and the project financing of a portfolio of data centres.
- The sponsor on the development of a new CCGT and OCGT thermal plant in the Irish midlands.
- General Electric Company on all of its Irish infrastructure and power assets, including over 300MW of wind generation and a large independent 400MW CCGT thermal generating station.
- Partners Group (UK) Limited, a global private equity firm, on its acquisition of an interest in the Greenlink Interconnector, a project to construct a 500MW subsea electricity interconnector between Ireland and Great Britain.
- Sponsors on their due diligence and bids for fibre networks assets in Ireland.
- enet, the PPP company which operates a wholesale fibre network in Ireland.
- Lenders to the largest ever higher education PPP undertaken by the Irish State. The TUD Grangegorman PPP acts as one of the centrepieces of the Government’s policy of making Ireland’s education and training service the best in Europe by 2026.
- John Sisk & Son on the development, construction, financing and restructuring of the Greystones Harbour PPP (and associated residential and commercial elements) with Wicklow County Council which was one of the largest and most complex mixed use development PPPs ever undertaken in Ireland.
- Caterpillar Inc in relation to its tender to Irish Rail for the largest locomotive overhaul the State railway operator has undertaken in decades.
- Numerous international sponsors, lenders, contractors and operators on Operational PPPs in the road, education, healthcare and justice sectors on an ongoing basis.
- Irish and international lenders and sponsors on the project financing of over 1.2GW of renewable energy assets in Ireland over the past few years alone.
- University College Dublin (BCL)
- Qualified as a solicitor in Ireland
- Qualified as a solicitor in England and Wales (non-practising)
- Project development: IFLR1000 2017

