This work proposes and analyses severalintegration schemes specially conceivedfor direct steam generation inMW-range central receiver solar thermal power plants. It is focused on the opticalperformance related to the heliostat field and the arrangement of receiver absorbers, and the management of steam within a Rankine cyclein the range between 40-160 bar and 400-550 ºC at design point. The solar receiver is composed of one single element for saturated steam systems or two vertically-aligned separated units, which correspond to the boiler and the superheater (dual-receiver concept), for superheated steam solar thermal power plants. In the second case, the heliostat field is divided in two concentric circular trapezoids where each of them independently supplies the solar energy required by the boiler and the superheater for the different steam conditions.From afixed heliostat fieldobtained after layout optimisation for the saturated steam solar plant and a live steam condition, two-zone solar fields are established according the necessary thermal power onto boiler and superheater. It has been observed that the arrangement locating the boiler above the superheater provides a slightly higher optical efficiency of the collector system, formed by the solar field and the receiver, compared to the reverse option with superheater above boiler. Besides two-zone solar fields providelower performances than the entire heliostat layout aiming at one absorber (saturation systems). Optical efficiency of two-zone solar fields decreases almost linearly with the increment of superheater heat demand. Concerning the whole solar collector, heliostat field plus receiver, theperformance decreases with temperature and almost linearly with the steam pressure. For the intervals of steam pressure and temperature under analysis, solar collector of saturated steam plant achievesan optical efficiency 3.2% higher than thesuperheated steam systemat 40 bar and 400 ºC, and the difference increases up to 9.3% when compared to superheated system at 160 bar and 550 ºC. On the other hand, superheated steam systems at 550ºC and pressure between 60 and 80 barprovide the highest overall efficiency, and it is 2.3% higher than performance of a saturated steam solar plant at 69 bar. However if saturated steam cycle integrates an intermediate reheat process, both would provide similar performances. Finally, it has been observed that central receiver systems producing saturated steamand superheated steam at 500 ºC operating at 40 bar provide similar performances.
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