1. Solar Neutrino Flux -- in 3 lines
Energy
Neutrinos
Energy from Hydrogen Burning:
4 p + 2 e- --> 4He + 2ne MeV
Measured power reaching Earth:
137 mW cm-2 = 8.53 x 1011 MeV cm-2 s-1
So… the neutrino flux is
2 x 8.53 x 1011
26.731
= 6.38 x 1010 ne cm-2 s-1 1

2. Solar Irradiance

3. The Neutrino Luminosity
Some corrections and assumptions:-- Neutrino losses ~2 +/- 0.2%
Residual heat from formation (gravitation, deuterium burning) <<1%
Quasi-static burning
MeV-1cm-2s-1
The practical problem 
The Luminosity Constraint:
I = 85.31(34) x 1010 MeV cm-2 s-1 (solar irradiance)

4. What do we need? pp get from pep pep we need this key
7Be we have it (thanks Borexino)
CNO limit to <1%
8B we have it (thanks SNO, SK)
hep limit <<1% (thanks SNO)
θ12 this is the other key. Now 2.2%! (SNO)
θ13 coming soon
(Haxton and Robertson 2011)

5. E=mc2
4p + 2e  4He + 2 ?