Let g be a general affine Lie algebra associated with a Lie algebra g equipped with a symmetric invariant bilinear form <,>. It is known that for every complex number l, we have a canonical vertex algebra Vg(l,o), and if (g, <, >) satisfies certain conditions, Vg(l,o) is a vertex operator algebra. In this paper, we consider g to be a finite-dimensional solvable Lie algebra equipped with a nondegenerate symmetric invariant bilinear form, and we show that Vg(l,o) contains a Virsoro-vector ω so that (Vg(l,0), Yv, 1,ω) is a vertex operator algebra.