Soltrace linear fresnel plus#

The angle of the mirrors is determined by the vector towards the sun projected onto the vertical axis running north-south. The East-West orientation offers possibly the most complex tracking.

Thus there will be a maximum half angle loss of cosine 22.5 and a total daily loss of the integral of cos (1/2 theta) from theta =-22.3 to 22.5

Soltrace linear fresnel plus#

(calculations at Solar_Collector_Calculations#Losses_due_to_edge_effects_onlyР”Р„lso, the reflectors move between plus and minus 22.5 degrees of tilt from 9am till 3pm. Since we do not wish to tilt the array towards the south for construction cost reasons (same as polar), and wish to collect energy during the winter, The factor E Farm team has shied away from this orientation as well.

Due to the latitude of the Factor E farm, the end losses associated with the shallowness of the suns angle parallel to the axis of the collector would be severe in winter if this orientation were laid flat on the ground. Tracking may be as simple as in polar or it may have hidden complications (We don't know). The North-South orientation is similar to the polar orientation, but may be flat on the ground. Thus, the Factor E Farm team has decided against this. However, due to the need to incline the absorber and reflectors, this orientation requires more structural considerations (and expenditures) than a flat (of the ground) approach. Tracking here is the simplest, as the mirrors need only rotate at half the angular speed of the earths rotation.

The Polar orientation focuses on a line parallel to the pole of the earths rotation, that is, inclined and running north-south. The effect varies with the half angle between the sun and the collector and the efficiency of light reflected is given as the cosine of the half angle (e= Cos(1/2 theta)Р”В®ach of these three possible orientations has associated tracking issues and also efficiency losses specific to that orientation (end losses and half angle losses). Lastly, the effect of the mirrors not being perpendicular to the sun is a loss in flux reflected by the mirror. o is given by h*Tan(theta) where h is the average distance between the collector and the reflectors and theta is the angle of the incident light in the plane parallel to the axis of the reflectors. The efficency of a linear collector experiencing edge effects is given by e=(L-o)/L where L is the length of the collector and o is the average offset caused by the angled light. The complexity of this tracking varies however with different orientations.Р”Р„lso, since a linear focusing system tracks in only one dimension, it suffers losses due to rays parallel to the axis of the trough coming in at a shallow angle and (though hitting the mirrors) missing the collector. In any orientation, the sun must be tracked minute by minute. Implementation dependent losses and issues Given an estimate of available energy for a particular day of the year, actual performance estimates can be made, and (once operable) efficiencies measured. 2 Implementation dependent losses and issues.