Creating Energy Solutions That Work

Core Values

EPSIM Corporation’s combined expertise and experience in specialty engineering and utility management fosters the incubation of ideas that transcend traditional silos of consulting. As a result, our team is uniquely positioned to develop, implement and manage innovative client solutions.

Our Mission

To develop innovative engineered solutions and serve the public utility industry and its stakeholders safely, responsibly and aggressively.

Our Vision

To merge knowledge in public utility operations and process engineering, the combination that will support innovation in energy generation and distribution for the 21st Century and beyond.

Years of Consulting Services

MW of Transmission and Distribution Capacity Management

Countries Where We Have Customers

Tons of Oxygen Capacity Built


Nils E. Tellier, P.E.

Founder and Principal

Nils Tellier has been a practicing engineer for 15 years and holds Professional Mechanical Engineering licenses in Colorado and Arizona. He founded EPSIM Corp in April 2012 where he serves as Principal.

Prior, Mr. Tellier was Director and Principal for the firm Robertson-Bryan, Inc. (RBI). During his six years at RBI, he established and directed the operations for two Client utilities, with combined annual budgets of $45 million. He developed simulation models to help Clients optimize loads, explore project feasibility, and inform policy changes. In 2009, he supervised Client utilities transition as the California ISO implemented its Market Redesign and Technology Upgrade (MRTU).

Mr. Tellier also directed the creation of an energy market on behalf of the Central Valley Project Corporation for the Western Area Power Administration and several of its customers, including Sacramento Municipal Utility District, Northern California Power Agency, Modesto Irrigation District, Silicon Valley Power.

Before joining RBI, Mr. Tellier had a consulting practice – NTCI, Inc. – which he founded in 1995 to provide engineering services in industrial gases and cryogenic processes.

As Client Representative, he managed the construction, start-up and commissioning of more than 20 capital projects in North America, South America, Australia and South East Asia. Clients included the Air Liquide Group, Kvaerner Chemetics, the Electrical Power Research Institute, E. I. DuPont, Phelps-Dodge Mining Corp, and the National Energy Technology Laboratory. In 2001, RBI tasked Mr. Tellier with the feasibility study and package design for 12 MW distributed generators. In 2004, he developed the load and resource planning models for a new public utility, led the development of the operation software – SAMBA – and, in 2005, directed the operations of the nascent utility on behalf of RBI.

Prior to founding NTCI, Mr. Tellier worked for the Air Liquide Group.

Mr. Tellier has authored two US patents, one on nitrogen process and another on power generation.

He is past Chair of ASME’s Cryogenic Technical Committee.

Mr. Tellier is a retired officer from the French Navy’s Groupement de Fusiliers Marins – Marine Nationale