This paper elaborates an alternative energy concept involving a solar power plant with a short diffuser. The main physical part of the proposed alternative energy source is a gravitational vortex (convective vortices) that can be thought of as a heat engine. A solar power plant with a short diffuser could produce electricity without carbon dioxide emissions by transforming the available solar energy into useful mechanical shaft work. The proposed concept is similar to the solar chimney power plant concept, but without a chimney of limited height; in that sense, the design is closer to the atmospheric vortex engine concept. Specific details about the proposed alternative solution, previous research outcomes and planned future research work will be discussed in this paper.