E4 Capital is Chad E. Brown and William J. Birmingham. We are an independent research firm started in 2009 providing ideas to professional investment managers about cleantech. Cleantech, a recent coinage, is defined broadly as the part of the investment world that focuses on businesses that reduce human impacts on the environment. It is not an industry classification. It includes segments from such industries as energy generation, energy storage, energy infrastructure, energy efficiency, transportation, water & wastewater, air & environment, materials, manufacturing/ industrial, agriculture, and recycling & waste.