I realize this is an old post, but...
This is a matter of quantum electrodynamics. If one studies the propensity for refraction of photons (light) as the photons intersect a junction, it will be shown that more protons are refracted as the angle of intersection is increased. In this case there are at least two major junctions that need be included in any calculations. The first is the junction of outer space and the earth???s atmosphere. Second is the junction of the air at the solar panel location and the glass surface of the solar panel.
If you consider the outer space and atmosphere junction it is easy to understand the refraction effects if you look at the difference in normal temperatures between the earths???s Polar Regions and the equator. Obviously, the sun illuminates the equator more directly than it does either the north or South Pole and the difference in refraction between the equator and the poles results in a substantial difference in absorbed energy (heat.) This same effect occurs in the morning and in the evening when the sun is rising or setting on a given area. So, the greatest amount of energy is available at the time of day that the sun is most directly impacting a given area at any geographic location.
There is a similar effect for the air and glass junction of the solar panel itself. Suffice it to say that the most energy will be absorbed by the panel if the directions of the photons are exactly perpendicular to the collecting surface of the solar panel.
Due to the cost of each panel it is preferred to have each panel generate the most amount of power possible each day so as to reduce the amount of time required to pay back the cost of purchase with energy savings due to power generated. Unless a movable and aimed solar panel is adjusted throughout the day to keep the sun oriented perpendicular to the collecting surface of the solar panel then the most efficient position is to have a fixed panel aimed so that it is perpendicular to the point of apogee for the sun at that geographic location.
This is one of the reasons that solar power is not the only power solution we will ever need. Until such time that we have a power storage system that can store power during the sinusoidal peaks so that it can be release to the grid during the troughs we will need other energy sources to make up the difference.
The phenomenon that Aidan identified is a way to ease the sinusoidal shape of the power generation cycle and make the power generated more consistent throughout the day. The only problem I see is that it would make the output of each panel not oriented perpendicularly to the daily solar apogee produce less energy than an optimally aligned solar panel. This alone will be cost prohibitive until the costs of solar panels are far below current prices.
