The core team that developed the HOMER software at NREL migrated along with the software code to HOMER Energy.
In addition, the team adds new professionals with experience in renewable energy, software development, management, marketing, and entrepreneurial ventures.
Peter Lilienthal, Ph.D., Chief Executive Officer
Dr. Peter Lilienthal is the original developer of the HOMER® software and founded HOMER Energy in 2009 to enhance
and commercialize the software. He has a Ph.D. in Management Science and Engineering from Stanford University.
Peter has been active in the field of renewable and distributed energy and energy efficiency since 1978. Before
founding HOMER Energy, he was president of Green Island Power, which provided analytical services for renewable
and distributed power projects. From 1990-2007 he was Senior Economist with the International Programs Office
at the National Renewable Energy Laboratory. His experience has included project development of distributed power
projects, designing and teaching courses at the university level, and consulting to industry and regulators.
His technical expertise is in utility modeling and the economic and financial analysis of renewable and distributed
power projects. He was the lead analyst and one of the creators of NREL’s International and Village Power Programs.
Marilyn Walker, Ph.D., Chief Operating Officer, Director of Academic Relations
Dr. Walker is a serial entrepreneur and experienced technologist. She started her career in academia, earning a
Ph. D in Biology from the University of Colorado and publishing over 50 technical publications on modeling and
environmental analysis. In the university setting, she raised over 12 million dollars to make her programs
financially sustainable and gained valuable knowledge in the fields of software, databases, modeling, and analysis.
After 20 years in academia, she became an entrepreneur by purchasing, managing, and selling a successful business,
PlayFair Toys. She founded and built two e-commerce companies, and has led multiple international and multidisciplinary
teams. Dr. Walker brings her unique, in-depth experience in environmental systems and business operations to her role as COO.
Howard Alt, Chief Technology Officer
Howard Alt brings more than 20 years experience in software and systems to his position as the Software Project
Manager at HOMER Energy. Over his career he has worked in businesses from startups to Fortune 500 as a software
engineer, QA engineer, engineering manager, product manager, chief technologist, entrepreneur and CEO.
Andy Kruse, VP for Business Development
For nearly 30 years Andy Kruse has been involved in international marketing, sales development of certification standards
and public policy. As a co-founder of a Start-up clean-tech company in Arizona, he built Southwest Windpower into
an internationally recognized brand within the clean energy industry which sold more than 180,000 wind generators
worldwide. He has traveled to and worked directly with potential distributors in 72 countries. Later he joined
Endurance Wind Power and established one of the first small wind leasing programs in the U.S. Most recently he
worked as a consultant to a number of wind and solar companies in Europe where he has lived the last year.
Andy’s passion for international sales has been recognized numerous times by various agencies and trade associations over
the years. He was awarded Exporter of the year by the US Export-Import Bank, the Small Business Administration
and he received the President’s E award from the US Department of Commerce. The American Wind Energy Association
also awarded him Small Wind Person of the Year in 2009.
Diane Rieck, Controller
Diane has long been involved and interested in the environmental sector and serves as HOMER Energy’s Controller.
She was a founding member of Wildlands Restoration Volunteers in Boulder, later taking over their accounting
operations and in addition has worked with multiple local accounting clients over the last decade. Previously,
Diane worked for American Express in New York City. She has an MBA from New York University and was an active
volunteer for NRDC. Diane loves balance, a theme she sees compatible and necessary in both accounting and nature.
She enjoys biking, hiking, gardening, knitting, cooking, reading, the list goes on and on…
John Glassmire, Director of Energy Engineering
John Glassmire is a globally-minded engineer who has worked across a wide-range of infrastructure projects. He has
interests in sustainable design, renewable energy, project management, and international development. John’s
undergraduate background is in mechanical engineering. After earning his BS from Rice University and his Masters
from Northwestern University, he worked for 2 years at Sargent & Lundy, a major energy design and consulting firm
in the US. Subsequently, John worked as a consultant in energy and water infrastructure at the Institute for
Sustainable Futures in Sydney, Australia.
David Rinck, Renewable Energy Engineer/C++ Programmer
David Rinck develops the analytical tools and methods within HOMER’s modeling engine. A mechanical engineer and
C++ programmer, David's research and professional experience in data analytics and controls ranges from projects
in solar thermal concentration to critical care medical devices. He has a strong interest in renewable energy,
micro-grids and their potential impact in the developing world. He received his Master's in Mechanical Engineering
with a concentration in energy systems at Columbia University, where he worked with the Earth Institute's Millennium
Jonathan Awerbuch, Energy Engineer
Jonathan supports the software development team by maintaining the quality, accuracy, and documentation of new
releases of the HOMER software. Jonathan received the A.B. in Engineering Sciences and the M.S. in Mechanical
Engineering from Dartmouth College in 2007 and 2009 respectively. He received the M.Eng. from Yale University
in 2010. His fervent interest in the impending energy/environmental meta-crisis motivated publications and
research including power electronic and ultracapacitor systems to improve electric vehicle efficiency, photovoltaic
performance in the presence of output ripple and noise, and energy efficient electrothermal deicers, particularly
for commercial wind turbines.
Aarabi Madhavan, Renewable Energy Analyst
An ardent fan of Marvel's Iron Man, Aarabi aims to use engineering to solve one of the world’s growing concerns:
access to clean and cheap energy. Realizing that solving the energy crisis requires an understanding of technology,
policy, and people, she pursued a graduate degree in Sustainable Energy from Columbia University. At Columbia,
she created business models for "bottom-of-pyramid" energy entrepreneurs, consulted on energy storage strategies
for a Fortune 200 energy company, studied global energy policies, and worked as a graduate researcher at Sustainable
Engineering Lab. Her graduate research involved developing a heuristic Geo-spatial network algorithm for grid
connection in Sub-Saharan Africa. As a Renewable Energy Analyst at HOMER Energy; she works on consulting projects,
creating and analyzing models for rural electrification, and also writes code to develop and test new features
of the HOMER PRO software. She is learning Swahili and hopes to lead rural electrification projects in Sub-Saharan
Africa and Asia.
Aleph Baumbach, Sales and Support Engineer
Aleph Baumbach graduated with two degrees: one in engineering (ABET accredited) and one in psychology from Fort
Lewis College in Durango, CO. He believes that while engineering can help us improve the living systems and
products that make our civilized world, that if we are to change to a more sustainable approach, change must
arise from within. This is why he decided to pursue a double major in psychology – to study the inner human
world – and engineering – to study how we can generate solutions to a variety of problems. As part of his
interests in renewable energies, the environment, and sustainability, he served in the board of directors for
the Environmental Center in Durango, CO for four years. He also was part of a project to bring potable water
and a sanitation system for an indigenous village in Ecuador and in Laos with Engineers Without Borders. With
his multi-cultural background, Aleph also speaks Spanish, Portuguese, and some German, which he uses to help
HOMER’s customers worldwide with their technological issues as Support Engineer and Client Services Specialist.
Andrew Flynn, Sales and Support Engineer
Andrew has a diverse educational background, tailored to help solve modern issues in renewable energy technology.
Equipped with undergraduate studies in environmental economics, public policy, and business at the University
of Connecticut followed by a master’s degree in Renewable Energy Development from Heriot-Watt University’s
Orkney Islands Campus, Andrew spends his days on support and business development efforts. Although he misses
the stormy Scottish seas from his grad school days, if there is one thing Andrew has learned, it’s to take
advantage of the sun. You can find him playing in the mountains or out on the soccer pitch.
Osie Adelfang, Microgrid News & Insight Editor-in-chief
Osie has been a writer, editor, and marketing professional for two decades, with much of that time spent in the
technology and software industry. At HOMER Energy, she edits the Microgrid News & Insight newsletter and
website/blog. She holds a BA in journalism from the University of Massachusetts and an MFA in nonfiction writing
from Antioch University. She has worked and freelanced for software startups, tech-industry government contractors,
technology trade shows, magazines, and more. For several years, she served as marketing director and CFO of her
husband's award-winning design/build firm. In addition to her work at HOMER Energy, Osie's focus is on family
life with her husband and four children. She and her family moved to Boulder in 2015 and are enjoying all their
new hometown has to offer. Osie also serves on the board of directors of Boulder-Nablus Sister City Project and
is active in human rights and social justice issues.
Henry Hunsinger, Digital Marketing Assistant
Recently graduated from the University of Colorado Boulder in digital marketing and advertising, Henry Hunsinger
provides critical marketing and sales efforts to streamline complex business processes. In addition, he is
Homer Energy’s in-house Salesforce administrator, working with and organizing large databases of information.
Henry has also worked in social media marketing and is excited about creating valuable marketing experiences
through every medium. Growing up in the mountains of Breckenridge, Colorado, Henry developed a deep passion
for the outdoors and has been skiing since he could walk. On any given blue-sky weekend, you’ll find him taking
turns through fresh powder, splashing around Boulder Creek, catching some rays on Pearl Street or hiking through
the beautiful Flatirons in Boulder.
Steffi Klawiter, Component Library Manager
After completing her Bachelor’s thesis on the topic of galaxy movement at the University of Wisconsin – Madison,
Steffi decided to re-direct her studies toward the nearer natural world. Utilizing her German language skills,
she relocated to Freiburg, Germany to study Renewable Energy Management and to learn from Germany’s largely
successful transition to renewables (‘Energiewende’). Steffi’s Master’s thesis on the feasibility of solar
manufacturing in Saudi Arabia, in combination with her internship with a solar thermal system in Mongolia,
have further inspired her interests in distributed energy, microgrids, and solar on the international level.