Additive manufacturing is the buzz word these days and many companies are leaning on this technology to leap forward in un-chartered design space that promises to give better performance at impossible to reach design goals with the current manufacturing methods. This paper addresses recent developments that have occurred in Energy related businesses with the adoption of 3D printing, also known as Additive Manufacturing (AM). It covers what and why of additive manufacturing; what constitutes energy and AM industry; current activities in AM for energy; AM for different energy sectors; AM processes; AM applications; selected patents in additive manufacturing associated with energy applications; and economic and financial aspects of AM in energy related industries. In this review paper it was noted that in-spite of phenomenal growth in AM, it seldom replaces traditional production methods due to associated constraints. Many companies are finding complimentary AM processes along with subtractive manufacturing techniques to meet the market demands. However, AM is particularly advantageous and attractive compared to traditional manufacturing methods for low volume complex geometry parts. Many times, complicated internal features produced using AM are not evident to an observer and an AM component with touchups may be indistinguishable from existing components with its external appearances alone. But note that inner details may differ significantly in AM made parts with tangible performance benefits over conventional parts. Some of the patented ideas presented here provide an insight into the inner complexities in geometry that can be achieved with AM to get distinct advantages that are nearly impossible to achieve economically from conventional machining. We notice, new engineers coming out of universities are already exposed to design techniques for additive manufacturing and they are also more trained on relevant numerical techniques than their predecessors graduated a decade ago; thus, new engineers are more open to embrace this technology. This paper provides not only the engineering aspects, but also includes the business and invention side of the AM pertinent to the energy industry. Hopefully, this article helps the AM community to get updated with different features of new development in energy industry and brings up new ideas to apply AM for achieving better performance from existing as well as new products. Keywords: Additive Manufacturing; Energy Industry; Wind Energy; Solar Energy; Gas Turbines; Batteries; Fuel-Cells; 3D printing; Turbine Airfoils. ______________________________________________________________________________ 1. Introduction: We are at an interesting time to observe unfolding of a new era of not only manufacturing but the design of components with a different mindset, an additive focused mindset instead of subtractive thinking. For example, in cast and drill design, one selects the discrete size of a drilled hole to match the drill bit. Moreover, in casting the designer must keep the liquid metal flow path and solidification 2 direction in mind while designing a component. In AM, those requirements are relaxed as manufactured holes and internal hollow channels could be built-in while the component is being printed. Further, the designer can better optimize for the strength and weight requirements of the application without being constrained by the tooling and associated tolerances. Briefly put, AM is a manufacturing process that builds a component from nothing to something. Conventional machining starts with a cast or forged shape that is usually significantly bigger than the final product and it chips away material to provide the final shape. In contrast, AM starts with a build plate with nothing on it and builds the final part one layer at a time. So, an AM device can produce a multitude of shapes and geometries provided the component size is within the machine’s operating range. Most review publications in additive manufacturing adopt appealing images collected from marketing sources but do not provide the inner technology. This paper takes a different approach by undertaking a deeper investigation into the inner workings of AM with a business perspective that a display of components does not provide. Some publications have more than 150