Exponential potentials for tracker fields

We show that a general, exact cosmological solution, where dynamics of scalar field is assigned by an exponential potential, fulfils all the issues of dark energy approach, both from a theoretical point of view and in comparison with available observational data. Moreover, tracking conditions are discussed, with a new treatment of the well known condition $\Gamma>1$. We prove that the currently used expression for $\Gamma$ is wrong.