The following is an excerpt from Practice Perspectives: Vault's Guide to Legal Practice Areas.
Gregory (Greg) W. Lavigne, Jr., is a partner in Sidley’s energy, transportation, and infrastructure group, where he advises energy investors, lenders, and sponsors on complex financing and M&A transactions, including project finance, tax equity, private equity, joint venture, M&A, and structured finance trans-actions. Greg’s clients are global, but his work is primarily focused on U.S. domestic projects. He has a long track record in traditional renewables and energy transition investments, with a strong background in solar, onshore and offshore wind, and battery storage assets. He also has extensive experience in transactions around liquified natural gas terminals and pipelines, combined-cycle gas turbine financings, green hydrogen and ammonia, EV and recycling infrastructure, geothermal projects, and other energy technologies. Greg’s practice thrives at the nexus of innovation, regulation, and finance as he helps clients structure transactions that drive sustainable outcomes while navigating evolving tax, regulatory, and market risk.
Describe your practice area and what it entails.
My practice centers on transactional work of all kinds in the energy sector, with a particular focus on renewables, energy transition, and other federally incentivized development. I advise clients on structuring, financing, and executing deals across the spectrum: tax equity, joint ventures, M&A, project finance, preferred equity, and structured credit. Because these deals often involve multiple moving parts (e.g., tax credits, regulatory incentives, power purchase agreements, interconnections, offtake, environmental attributes, and supply chain and contractor risk), the role requires being both deeply strategic and operationally pragmatic. In many ways, my job is to translate business objectives into legal structures that manage risk while enabling value creation.
What types of clients do you represent?
I represent a broad range of clients: private equity and infrastructure sponsors, tax equity investors and syndicators, lenders and institutional capital providers, and energy developers. My clients include global investment firms, energy companies, project platforms, and emerging tech companies in the clean energy space. As the energy transition sector continues to evolve, I have found myself working increasingly with clients such as recycling and advanced manufacturing firms, EV/infrastructure developers, and other adjacent businesses pursuing federally incentivized infrastructure investment.
What types of cases/deals do you work on?
My practice is driven by the asset classes I focus on rather than a single legal discipline, allowing me to work seamlessly across both financing and corporate matters. A typical trans-action is highly structured with multiple parts of the capital stack that must interact and support the development and operation of an energy or infrastructure asset.
Some recent transactions include Calibrant Energy (a Macquarie Asset Management portfolio company) in its acquisition of a carve-out of Enel X North America’s distributed energy storage business with more than 700 MWh of distributed projects in late-stage development; RBC Community Investments in invest-tax-credit equity financing of over $500 million for a Green River Energy Center project being developed by rPlus Energies, a 400-MWac solar photovoltaic facility and 400-MW/1,600-MWh battery energy storage facility located in Emery County, Utah; a consortium headed by APG Asset Management N.V., on behalf of the largest Dutch pension fund ABP and Australian Retirement Trust, in the acquisition of Riverstone Holdings’ equity stake in Pattern Energy Group LP; EQT Partners in mezzanine debt financing to refinance the mezzanine and subordinate debt obligations of its portfolio company Cypress Creek Renewables; Macquarie Asset Management in a $325 million investment in Atlas Agro Holding AG, a developer of industrial-scale plants for fertilizer sourced from green hydrogen; Lombard Odier Asset Management in a structured debt financing of Tillman Networks’ telecommunications infrastructure development business; Apollo Global Management Inc. on convertible equity portfolio financing of $816 million with NextEra Energy Partners for a 2.5-GW renewable energy portfolio consisting of 13 utility-scale wind and solar assets and integrated battery storage of approximately 115 MW spanning U.S. power markets; DE Shaw Renewable Investments in the acquisition, development, tax equity, and project financing of the High-lands solar project; and Global Infrastructure Partners in its acquisition of 50% of TotalEnergies’ majority ownership position in SunPower Corporation.
How did you choose this practice area?
I’m fascinated by the intersection of law, finance, and sustainability, and this field offers all three in equal measure. I have a master’s degree in urban planning that I received alongside my law degree, and I’ve always been interested in how policy impacts the real world. Early in my career, I was drawn to project finance and infrastructure, and as renewables matured and the energy transition agenda accelerated, I saw the opportunity to focus fully on this space. The pace of innovation; constant policy developments, especially around tax credits and clean energy incentives; operational complexity; and scale of capital involved all made the work particularly compelling to me. I enjoy helping clients achieve real-world impact through com-plex transactions that this practice area allows me to do.
What is a “typical” day like and/or what are some common tasks you perform?
Every day in my practice looks different, which is a big part of why I find the work particularly engaging and exciting. A given day might involve strategy calls with a client on an M&A trans-action, underwriting and diligence analysis on a tax equity investment or project financing, analyzing new regulatory guidance on tax credits or federal loan programs, or walking through different options and upside/downside protection in a workout. Much of my time is spent coordinating with various colleagues at Sidley to ensure our clients are getting the best advice on every part of the strategy, then synthesizing all of the different work streams into commercial action that helps them achieve the best outcomes. My days are intensely transactional, highly collaborative, and often driven by tight deadlines and shifting deal parameters.
What training, classes, experience, or skills development would you recommend to someone who wishes to enter your practice area?
The most impactful classes I took in law school were seminars. Any courses taught by a practicing transactional lawyer or are otherwise grounded in real-world practice will give you the clearest sense of what work will feel like in a commercial environment. If you want to pursue a practice in finance, Secured Transactions is a critical course and will be part of your daily life. I also find that general Corporations Law is really helpful, as is gaining at least a basic understanding of tax even if you don’t plan to specialize. Outside of the academic environment, I have two pieces of advice. First, you need to understand the business environment in which your clients operate. In an energy practice, learning how the energy markets and the electrical grid function will take you far, as will having a basic understanding of the basic vocabulary of these markets. Second, in any finance or corporate practice, you should stay current on legal and commercial environment changes. Take a real interest in your client’s business and engage with the media that they are following to learn how to look around corners and anticipate their concerns.
One great yardstick for developing your skills is making sure you understand what your counterparts on the client side are responsible for and helping them to be successful. This might mean learning how a financial model works, assessing risk, gathering internal information for a regulatory filing, or developing a strategic approach. My other core piece of advice is that attention to detail, the ability to manage multiple moving parts, and strong drafting abilities are table stakes for being an excellent lawyer, but you will stand out if you learn how to deliver clear, effective, and actionable advice.
What is the most challenging aspect of practicing in this area?
The biggest challenge is working through the complexity and rapid change inherent in this sector. Regulatory regimes, supply chain and interconnection risk, changes in tax equity and governmental incentive policy, credit markets, and ESG/ transition mandates all shift with market and policy forces. Structuring a deal that aligns incentives across sponsors, investors, lenders, contractors, and offtakers while managing evolving risk (technical, regulatory, tax, and environmental) is demanding. Especially for large portfolios or cross-border transactions, coordinating multiple stakeholders and jurisdictions increases the challenge. This same complexity is also what keeps the work compelling.
What misconceptions exist about your practice area?
One misconception is that energy and infrastructure transactions can be easily done by generalist corporate or financing associates. In reality, energy and infrastructure assets are highly regulated and subject to a wide range of policy and tax consequences, physical constraints, supply chain and technology risk, and many other unique factors that require deep specialization to identify, understand, and manage. These deals are uniquely complex and require seasoned lawyers who can pull in a variety of different specialist perspectives, filter the critical from the preferred, and help commercial clients make risk-adjusted decisions. Some assume a lawyer’s work is purely technical, but at the highest levels, the job also requires commercial instincts, business savvy, and creativity to structure transactions that actually succeed in the market.
How do you see this practice area evolving in the future?
I see several key trends: greater scale and sophistication in renewables and storage, increased investor appetite for nuclear and renewed interest in baseload generation, increasing interest in circular-economy technologies as supply chains become increasingly regulated and constrained, and increasing regulatory and tax policy complexity. At the same time, the rise of AI and the growth in data center demand may point to an infrastructure boom, driven fundamentally by global competition to produce the lowest-cost energy capable of powering this revolution. Shifts in supply chain resilience, localization of manufacturing, and cross-border investment flows will drive structuring demands. For legal practitioners in this space, staying ahead of policy, tax, and regulatory shifts will be a differentiator.
What are some typical career paths for lawyers in this practice area?
Lawyers often start as associates in energy, project finance, or infrastructure groups then move into roles focusing on certain types of transactions. It’s great to be a generalist as you develop as a lawyer, but you also need some anchor practices that allow you to be recognized as someone who clients or colleagues turn to for specific transactions.
Outside the law firm, some lawyers transition to in-house roles at sponsors, investment firms, or infrastructure platforms. Others move into governmental or regulatory roles (energy commissions, DOE, etc.) because of the strong policy interface. Within law firms, progression to counsel or partner is typical for those who develop a deep transactional and client-relationship track record.
Beyond law practice, many go into advisory, consulting, or board roles in the energy and infrastructure sectors. The cross-disciplinary nature of the work opens many doors.