John Cromer is a graduate of the University of Pennsylvania with a BSE degree in mechanical engineering with 12 years of industry experience designing and installing residential and commercial solar photovoltaic power projects up to 1MW in size, with an emphasis on rooftop solar. Before transitioning into the solar industry, he worked as a control system engineer in oil and gas for Fluor Corporation. He has since obtained his Master Electrician and Residential Contractor certificate of responsibilities, as well as a NABCEP PV Installer industry certificate.  Writing and teaching solar training programs in between projects, his latest programs include content on batteries and electronic load control, for both residential and commercial applications. He is the founder of energy controller company Levll.