Description of a new designed Solar Trough System
Drive Unit
-	two single-acting hydraulic cylinders are moving through a strong chaine a wheel that is connected with the trough structure.
-	the unit is completely closed, delivered fully assembled and tested by one manufacturer, including power unit.
-	the rotation movement is free of tolerance.
-	the max. torque moment, calculated and designed = 140 kNm
-	weight of the drive unit, filled with oil = approx. 630 kg
Foundation of Drive-Unit
-	on site prefabricated concrete device with steel plate and bolts on top.
Intermediate Carrier
-	on site prefabricated concrete device with steel plate and bolts on top.
Trough-System
-	the absorber tube (o.dia.=approx. 80 mm, black steel with evacuated glass cover) is fixed in the focus of the trough.
-	the trough is turning around the absorber tube from east to west, about 180 degrees.
-	to the right and left side of the drive unit there are six trough sections, aligned in south-north axis, each section with 12 m length and 6 m aperture.
-	each section consists of 10 dishes (each of 2.4 m length) with parabolic curvature, made of compressed carbon fibre material.
-	on these dishes small rows of thin low iron glass back-silvered planar mirrors are fixed.
-	to hold the dishes there are at the ends and between 6 metal frames, their edges are bended by stainless steel ropes providing firm hold.
-	on the trough bottom the frames are connected with 5 triangular steel tube structures.
-	one entire trough section is hold and moved by 2 metal cantilever arms at the section's ends.
-	all of these trough parts are industrially produced in big quantities as well as tested and delivered in high-precision quality. They can be easily assembled in a simple jig and connected only with screws by semi-skilled people on site.
-	this around-the-focus rotating trough system requires a counterbalance weight as well as a torsion stabilization along the entire trough length.
-	this is achieved by a rectangular steel tube, welded together of 12 parts, each approx. 12 m long.
-	instead of a shadow on the trough bottom there is an open area by the width of the counterbalance tube, allowing wind load reduction and the assembly of water spray nozzles to clean the mirrors.
-	to increase ray tracking efficiency, a parabolic shaped counter mirror is fixed on the counterbalance tube diverting sun rays from there to the backside of the absorber tube, it also works as its carrier.
-	the weight of one completely assembled trough section is approx. 700 kg, without the counterbalance tube.
One trough section:
Both, design and calculation are showing a significant reduction of weight, production-, assembly- and transportation costs. In addition, a reduction of maintenance costs is highly probable. The costs concerning all mechanical and concrete parts as well as their assembly are detailed calculated with approx. 60 millions EUR (x) for a 50 MW plant, consisting of 630 trough lines. (x)=European price level
LEHLE GmbH Technik & Design robert.lehle@lehle-gmbh.de fax: +49 (0) 7034 26661 Teckstrasse 37 D-71116 Gärtringen Germany Registered: HRB 3902 Amtsgericht Böblingen VAT-Nr.: DE811926159