The present disclosure includes a petroleum-alternative power plant system harvesting wind, solar, and thermal energies. The system may include at least one two-wind-turbine power tower building where the outside surface of the building is divided into a number of sections. Each section forms a funnel- shaped duct to guide and accelerate the wind streams toward the vanes of the first wind turbine; then wind streams accelerated further and guided toward the vanes of a second wind turbine. The system may also include solar receptors, solar tower, and thermal receptors to harvest more energy. A management control subsystem is provided to combine electricity, and selectively delivering electricity to any electric load, a non-fossil fuel production subsystem, and the power grid.