  We discuss the constraints that future photometric and spectroscopic redshift
surveys can put on dark energy through the baryon oscillations of the power
spectrum. We model the dark energy either with a perfect fluid or a scalar
field and take into account the information contained in the linear growth
function. We show that the growth function helps to break the degeneracy in the
dark energy parameters and reduce the errors on $w_0,w_1$ roughly by 30% making
more appealing multicolor surveys based on photometric redshifts. We find that
a 200 square degrees spectroscopic survey reaching $z = 3$ can constrain
$w_0,w_1$ to within $\Delta w_0=0.21,\Delta w_1=0.26$ and to $\Delta
w_0=0.39,\Delta w_1=0.54$ using photometric redshifts with absolute uncertainty
of 0.02. In the scalar field case we show that the slope $n$ of the inverse
power-law potential for dark energy can be constrained to $\Delta n=0.26$
(spectroscopic redshifts) or $\Delta n=0.40$ (photometric redshifts), i.e.
better than with future ground-based supernovae surveys or CMB data.
