  We predict the sterile neutrino spectrum of some of the key solar nuclear
reactions and discuss the possibility of these being observed by the next
generation of solar neutrino experiments. By using an up-to-date standard solar
model with good agreement with current helioseismology and solar neutrino flux
data sets, we found that from solar neutrino fluxes arriving on Earth only
3\%-4\% correspond to the sterile neutrino. The most intense solar sources of
sterile neutrinos are the $pp$ and $^7Be$ nuclear reactions with a total flux
of $2.2\times 10^{9}\;{\rm cm^2 s^{-1}}$ and $1.8\times 10^{8}\;{\rm cm^2
s^{-1}}$, followed by the $^{13}N$ and $^{15}O$ nuclear reactions with a total
flux of $1.9\times 10^{7}\;{\rm cm^2 s^{-1}}$ and $1.7\times 10^{7}\;{\rm cm^2
s^{-1}}$. Moreover, we compute the sterile neutrino spectra of the nuclear
proton-proton nuclear reactions -- $pp$, $hep$ and $^8B$ and the
carbon-nitrogen-oxygen -- $^{13}N$, $^{15}O$ and $^{17}F$ and the spectral
lines of $^7Be$.
