How many 26 Watts CFL can be connected to a 2300W DUSK-DAWN PHOTO SENSOR? Please explain the meaning of difference in number of lights as shown in the attached image.
This really depends on the type of CFL you plan to use. The manufacturer considers power and capacitance: You shall not exceed 700 Watts on CFLs without sieve/smoothing CFL-capacitors, in your case 26 lamps max.
In case the lamps include sieve/smooting CFL-caps, you shall not exceed 290 W, resulting in 10 to 11 CFLs consuming 26 W each.