  We have performed a sequence of high resolution hydrodynamic simulations of
structure formation in a LCDM model to study the thermal and kinetic
Sunyaev-Zel'dovich (SZ) effects. Including only adiabatic gas physics, we
demonstrate that our simulations for the thermal effect are converged down to
sub-arcminute scales. In this model, the angular power spectrum of CMB
anisotropies induced by the thermal effect peaks at l~10^4, and reaches an
amplitude just below current observational upper limits. Fluctuations due to
the kinetic effect are a factor of ~30 lower in power and peak at slightly
smaller angular scales. We identify individual SZ sources and compute their
counts as a function of source strength and angular size. We present a
preliminary investigation of the consequences of an early epoch of energy
injection which tends to suppress power on small angular scales, while giving
rise to additional power on largescales from the reheated IGM at high redshift.
