The placement of fully available prime movers having a DC output at a location inside or adjacent to an inverter-based intermittently available renewable energy site is disclosed. The fully available prime movers add reliability to an unreliable energy asset that is reaching its maximum penetration within the grid due to its unpredictability and the requirement for additional spinning reserves in other parts of the grid. The present invention can provide a portion or all of the power to an intermittently available renewable power generating facility so that the power output to the power grid is dispatchable power. In particular, a method and means are disclosed to utilize high-efficiency engines operated on various fuels some of which may be non-fossil fuels to maintain a constant power output from an otherwise intermittent power generating facility.