  We study the matter effect caused by non-standard neutrino interactions (NSI)
in the future solar neutrino experiments, DUNE, HK and MICA. The upcoming
reactor experiment, JUNO is expected to provide the most precise measurements
of solar neutrino oscillation parameters and is going to open up the era of
sub-percent precision in the leptonic mixing sector of the Standard Model (SM).
Considering JUNO can measure $\Delta m ^2 _{21}$ and $\theta_{12}$ by
sub-percent precision and assuming SM as the null hypothesis, we study the
possibility to constrain NSI parameters by the future solar neutrino
experiments such as DUNE, HK and MICA. For this purpose, we study the effect of
NSI on solar neutrino propagation in the Sun and Earth and explore the
dependence of the day-night asymmetry on the NSI parameters. We also study the
effect of NSI at the water Cerenkov detector on the simulated data for these
experiments.
