Solar observations are performed over an extended field of view and the isoplanatic patch over which conventional adaptive optics (AO) provides diffraction limited resolution is a severe limitation. The development of multi-conjugate adaptive optics (MCAO) for the new large aperture solar telescopes ranging from 1.6 to 4 meters-diameter is extremely important to achieve many solar physics scientific goals. The Sun is an ideal object for the development of MCAO since solar structure provides multiple "guide stars" in any desired configuration. We propose a concept for an MCAO system for the New Solar Telescope at Big Bear Observatory. This MCAO system uses three deformable mirrors conjugated to the telescope entrance pupil and to two layers in the upper atmosphere. We present the result of numerical analysis of the performance of this system for large range of elevations as required in solar observations.