A concentrator tube comprises a reflector portion having two walls; and an aperture closing an opening to the reflector portion. The aperture and the reflector portion extend longitudinally. The aperture is substantially flat relative to curvature of the reflector portion.

Solar energy is collected and used for various industrial processes, such as oilfield applications, e.g. generating steam that is injected downhole, enabling enhanced oil recovery. Solar energy is indirectly collected using a heal transfer fluid in a solar collector, delivering heat to a heat exchanger that in turn delivers heal into oilfield feedwater, producing hotter water or steam. Solar energy is directly collected by directly generating steam with solar collectors, and then injecting the steam downhole. Solar energy is collected to preheat water that is then fed into fuel-fired steam generators that in turn produce steam for downhole injection. Solar energy is collected to produce electricity via a Rankine cycle turbine generator, and rejected heat warms feedwater for fuel-fired steam generators. Solar energy is collected (directly or indirectly) to deliver heat to a heater-treater, with optional fuel-fired additional heat generation.

A solar heat boiler is provided which is capable of avoiding damage to heat transfer tubes without increasing facility cost and construction cost. The solar heat boiler includes: a low-temperature heating device by which water supplied from a water supply pump is heated by heat of sunlight; a steam-water separation device by which two-phase fluid of water and steam generated in the low-temperature heating device is separated into water and steam; a high-temperature heating device by which the steam separated by the steam-water separation device is heated by the heat of sunlight; and a circulation pump by which the water separated by the steam-water separation device is supplied to the low-temperature heating device.

A receiver system for a Fresnel solar plant is provided. The system includes an absorber tube defining a longitudinal direction and a mirror array that runs parallel to the longitudinal direction. The mirror array has a mirror-symmetrical curve profile having at least one top apex for concentrating light beams onto the absorber tube. The mirror array has ventilation holes in the region of the apex.

The invention includes a parabolic solar concentrator typified by a highly integrated structure whereby, mirror, aerodynamic elements, a shell structure, cooling elements and other elements have been integrated to form a unibody structure, which is both stiffer and lighter than traditional trough structures. The invention includes; aerodynamic features that greatly limit lift forces induced by high speed winds, a receiver with liquid cooling for better control of PV cell temperatures and which allows for the collection of the heat for beneficial use, accommodations for a solar tracker, and improvements in the focusing and distribution of light using secondary mirrors. The receiver incorporates specific details to improve heat transfer and reduce parasitic pumping loads and incorporates secondary mirrors to increase light acceptance angles. Automated mirror washing is addressed. In applications where the heat is un-utilized the integrated radiator is employed to dissipate the heat using both convection and radiation heat transfer.

A dual-plate heat exchanger, in combination with a parabolic trough, ensures efficient absorption of solar rays by redirecting any lost or scattered rays, enhancing overall system performance and energy yield. Another heat exchanger comprises a cylindrical quartz tube.