We discuss precision measurements of PVDIS with the upgraded JLab 12 GeV beam by using a Solenoidal Large Iintensity Device (SoLID). The unique feature of SoLID, combining high luminosity and large acceptance, makes it possible to reach the high precision needed to have a high impact by using PVDIS to probe physics beyond the Standard Model. A measurement of PVDIS in deuterium will determine a fundamental coupling constant that is inaccessible with other means. PVDIS measurements can also access a number of topics in QCD physics, including searching for charge symmetry violation in the parton distribution functions, determining the d/u ratio in the proton without nuclear effects, and a clean extraction of higher-twist effects due to quark-quark correlations. SoLID allows a full exploitation of the physics potential of the JLab 12 GeV upgrade. In addition to PVDIS, it has a set of approved highly-rated experiments to study nucleon transverse spin and transverse structure by using polarized semi-inclusive DIS and to study non-perturbative gluon dynamics with J/Ψ production near threshold. A brief description of the SoLID spectrometer is also given.