Skip to main content


Willis Geffert specializes in the energy industry, focusing on international arbitration, litigation support, regulatory proceedings, and advisory services. He has provided in-depth analysis and advice as a testifying or consulting expert in 14 international arbitrations, addressing contract disputes, infrastructure concessions, regulatory policy, expropriation, valuation, and damages. Mr. Geffert advises governments, regulators, utilities, energy companies, and investors on energy market design, regulation, potential acquisitions or asset retirements, contract negotiation, and transaction due diligence.


Mr. Geffert has broad power industry experience. He advises clients in the US, Canada, Latin America, Europe, Asia, and Africa, analyzing power plants, transmission and distribution lines, fuel markets, price forecasts, production cost models, Power Purchase Agreements (PPAs), capacity auctions, and wholesale and retail rates. Mr. Geffert's experience spans all generation technologies, including renewables (solar PV, wind, hydroelectric, geothermal, and biomass) and thermal plants (natural gas, coal, oil, and nuclear), across numerous markets, including PJM, NYISO, CAISO, MISO, ERCOT, ISO-NE, Mexico, various Canadian markets, Ireland's SEM, Nord Pool, Russia, Pakistan, South Africa, Peru, Guatemala, and the Dominican Republic. Increasingly, his cases involve the transition from higher-emission resources like coal power plants to renewable generation. In the oil and gas sector, Mr. Geffert has worked on construction disputes, contract issues related to gas extraction, utility valuation, and retail pricing.

Mr. Geffert has supported clients in arbitrations (including before ICSID, ICC, and SIAC), disputes in US courts, and contested proceedings before the Federal Energy Regulatory Commission (FERC) and state and provincial regulatory bodies. He recently served as expert in an ICC arbitration for a Central American energy company, providing economic and energy sector analysis in a contract and construction-delay dispute related to a hydroelectric power plant.

In his regulatory work, Mr. Geffert frequently assesses retail tariffs and compensation for owning transmission and distribution assets. He also analyzes competition and market power potential. He helps run NERA's Marginal Cost Working Group.


  • MS in physics, University of Pennsylvania
  • BA in physics, magna cum laude, Amherst College