  The first two orbits of the Parker Solar Probe (PSP) spacecraft have enabled
the first in situ measurements of the solar wind down to a heliocentric
distance of 0.17 au (or 36 Rs). Here, we present an analysis of this data to
study solar wind turbulence at 0.17 au and its evolution out to 1 au. While
many features remain similar, key differences at 0.17 au include: increased
turbulence energy levels by more than an order of magnitude, a magnetic field
spectral index of -3/2 matching that of the velocity and both Elsasser fields,
a lower magnetic compressibility consistent with a smaller slow-mode kinetic
energy fraction, and a much smaller outer scale that has had time for
substantial nonlinear processing. There is also an overall increase in the
dominance of outward-propagating Alfv\'enic fluctuations compared to
inward-propagating ones, and the radial variation of the inward component is
consistent with its generation by reflection from the large-scale gradient in
Alfv\'en speed. The energy flux in this turbulence at 0.17 au was found to be
~10% of that in the bulk solar wind kinetic energy, becoming ~40% when
extrapolated to the Alfv\'en point, and both the fraction and rate of increase
of this flux towards the Sun is consistent with turbulence-driven models in
which the solar wind is powered by this flux.
