American Solar Home Page

Make the smart energy choice.℠

Northeast Florida (904) 268-8046
Central Florida (844) 279-0459


American Solar’s Leadership Team

American Solar has one of North America’s most experienced leadership teams. Our solar technology and industry experience began in the 1970s and 80s. Our deep experience and knowledge provides our customers with the peace of mind that their solar power systems, energy-efficient water heating systems and energy-efficient pool heating systems will be proven, reliable, and designed and installed correctly.

Mark Krenn Photo

Mark Krenn
Founder, President and Director

Mark Krenn founded American Solar in 1986 and remains the company’s majority shareholder and president today. He has more than 30 years of experience selling, installing and servicing solar energy systems. As one of Florida’s earliest solar contractors (the licensing category was created in the early 1980s), Mark has witnessed the industry’s ups and downs and its steady evolution in technology and installation techniques. He has served as a volunteer subject matter expert for the Florida Department of Business and Professional Regulation’s solar contractor licensing exam.

A strong believer in sustainability and renewable energy, Mark plunged into the solar industry headfirst in 1984, leaving his job as a successful regional sales manager for a Fortune 500 company to learn the solar business from the ground up. He took an entry level position as a solar installation technician with Energy Clinic, a 1980s era solar company. Within six months he was managing the company’s Jacksonville operations.

Many solar companies failed after the first solar tax credit expired in 1986, including Energy Clinic. But Mark saw opportunity in his employer’s failure and the industry downturn. He set up a service company to maintain and repair solar energy systems owned by the 1,700 Northeast Florida customers of his former employer. That solar service company, which he called “Energy Clinic Service Center,” later became American Solar. Mostly a one-man show for the first 15 years, Mark personally installed over 4,000 solar panels and serviced more than 2,000 solar water heating and solar pool heating systems.

Mark started his career as an investigator for Equifax (then known as Retail Credit Corporation). He next spent three years in life insurance sales, for National Life & Accident and Prudential Insurance. In 1977, he became an account executive for St. Regis Paper Company (since merged into International Paper). He sold several million dollars worth of construction products to county governments across 30 counties in southern Indiana, rising to regional sales manager in the company’s Bloomington regional headquarters. Mark earned a bachelor of science degree in sociology from Western Michigan University.

Jeff Prutsman Photo

Jeffrey Prutsman
CEO and Director

Jeff Prutsman is American Solar’s CEO. He has more than 30 years of experience with solar energy systems, including design, manufacturing, economic feasibility and due diligence analysis. He has consulted on several large commercial solar power projects, including due diligence review of utility-scale projects for the International Finance Corporation (IFC) subsidiary of The World Bank. His work for IFC included a due diligence review of the first private, utility-scale solar photovoltaic powerplant in India—a 2 Megawatt project constructed by Azure Power near Awan in the state of Punjab, which was funded by the IFC.

During the early 1980s, he provided consulting services to several Florida solar contracting companies. In 1982, he played a key role in the startup of Florida Solar Distributors, Inc., which became the world’s largest solar heating contractor during the 1990s. Jeff co-founded SEMCO Corporation in 1976, a pioneering firm in the modern solar energy industry. SEMCO manufactured one of the first solar collectors to be certified by the Florida Solar Energy Center and also conducted contract solar water heating research and development for NASA.1 SEMCO was a charter member of the Florida Solar Energy Industries Association (FlaSEIA), and Jeff authored the association’s first code of ethics.

He has also served as a planning & zoning commissioner, for Orange City, Florida, and he is a past publisher of Orlando magazine. Jeff earned a bachelor of science degree (BSBA) from the Warrington College of Business Administration at the University of Florida.

Robert Carl Photo

Robert D. Carl, III
Investor and Director

Robert Carl is an investor in American Solar and serves on the company’s board of directors. He founded and served as Chairman and President of Health Images, Inc. from 1982 to 1997, raising over $124 million in capital and growing the company from five to employees to 1,050 in 1997. During the 1990s, Health Images became the world’s leading vertically integrated provider of magnetic resonance imaging (MRI) services. Following a successful IPO, Health Images achieved listing on the New York Stock Exchange in 1993 (NYSE “HII”). Bob negotiated the acquisition of Health Images by Healthsouth Corporation in 1997. Three years later, he repeated his Health Images success with CSCM, Inc., an Atlanta-based operator of diagnostic medical imaging clinics, founding the company and serving as its Chairman, CEO and President until 2014.

Bob served as a director of VIST Financial Corporation (NADSAQ NMS “VIST”), where he played a key role in the 2012 acquisition of VIST by Tompkins Financial Corporation (AMEX “TMP”); and as a director of oil and gas producer Enex Resources Corporation, a former NASDAQ NMS company (“ENEX”) acquired by Middle Bay Oil in 1998.

He is a Trustee Emeritus of Franklin & Marshall College and currently serves as a Director of North Museum Corporation in Lancaster, Pennsylvania. Bob earned a bachelor of arts degree in history from Franklin & Marshall College and a law degree from the Emory University School of Law. He practiced law in Decatur, Georgia early in his career and he remains a member (inactive) of the State Bar of Georgia.

J Brewer Photo

John W. Brewer, III
Vice President of Sales

J. Brewer is a dynamic individual with deep experience in growing and managing technology businesses. He has primary responsibility for American Solar’s sales activities. He was the national sales leader for the UBuildIt owner-builder advisory service during the mid 2000s. He also has an extensive background in information technology and technology project management. His experience includes a decade at Lockheed Martin working in various information technology management roles, primarily in the areas of systems integration and networking.

After the advent of the commercial Internet, he cofounded and served as the CEO and president of IntelliSTAR, one of Central Florida’s five largest Internet services providers during the 1990s. During the dot com boom he was vice president of information technology for, an online provider of special event photography programs for a client list that included NBC, Sprint, Pepsi,, American Express, House of Blues, Sam Adams, Hollywood Records, Macy’s, Motorola and others. He helped negotiate a multi-million dollar acquisition of, and he subsequently served as the COO of EZPrints, a digital photofinishing service. J. earned a bachelor of arts degree from the School of Theatre at Florida State University.

John Prutsman Photo

John Prutsman
Vice President of Quality Assurance

John Prutsman is our Vice President of Quality Assurance. He has more than 35 years of experience in the manufacture, installation, troubleshooting and product evaluation of low and medium temperature solar water heating systems and solar power systems, having worked hands-on with more than 25,000 systems and 6 million square feet of solar collectors. He is the lead inventor of opaque cover technology for solar thermal collectors, which is currently patent pending in the United States, Australia, Brazil, China, India, Indonesia, Israel, Malaysia and South Africa.2

In 1982, John set up the operations department and created the installation manuals and technical best practices for Florida Solar Distributors, Inc., which was the world’s largest solar heating contractor during the 1990s. He later held a position as a national applications engineer for FAFCO, Inc., the world’s oldest manufacturer of unglazed plastic solar collectors, where his responsibilities included dealer field training and installation quality assurance throughout the United States. Prior to FAFCO, John was the Florida market qualifying contractor and quality assurance manager of swimming pool construction for Centex Homes.3 Centex Homes was the third largest U.S. homebuilder until it merged with the largest U.S. homebuilder, Pulte Homes, in 2012. John attended Mansfield University of Pennsylvania.



  1. The SEMCO FP-40, a medium temperature glazed flat plate collector. See also:
    Thermal Performance Evaluation of the SEMCO (Liquid) Solar Collector
    Solar Energy System Performance Evaluation – Seasonal Report for SEMCO, Loxahatchee, Florida
    Solar Energy System Performance Evaluation – Seasonal Report for SEMCO, Macon, Georgia
    Prototype Solar Domestic Solar Hot Water Systems (Collation of Quarterly Reports)
    Design Data Brochure: Solar Hot Water System
    Thermal Performance Evaluation of the SEMCO (liquid) Solar Collector: Florida Solar Energy Center, George C. Marshall Space Flight Center, U.S. Department of Energy, available for order (requires purchase) online at:
  2. See “Solar collector comprising an opaque cover,” U.S. Patent Application No. 20140305425 A1.
  3. John Prutsman held Florida certified commercial pool/spa contractor license CPC 056968 from 2004 to 2010.