Total land area - Power Tower

The total reflective area should be of some relationship to the total calculated land area. Could you please explain what this relationship is?

Total Land Area=Solar Field Area x (1+Non Solar Field Land Area Multiplier)
Here the SF Area = Actual Aperture x Row Spacing/Max. SCA width

but, is the Actual Aperture the same as the reflective area????

and, why in this formula they are using the "Non Solar Field Land Area Mult." if if the input the value is "Solar Field Land Area Multiplier", are they the same?

Or does this word "Non" before the "Solar Field Land Area Multiplier" means that I should subtract the typical value of 1.4 from 1 or something like that????

This was confusing for me too. I agree with Paul Gilman's summary (of Wed, 2012-03-21 17:33), but seek to clarify further.

The total reflective area (in m^2) is displayed by SAM, but the field area shown in the graphic (coloured in red) is not stated. This field area comes out (for a default SAM system) at about 3 times the reflective area, includes radial and azimuthal spacing between the heliostats, and is Paul Gilman's "Area of Zones Occupied by Heliostats (m)" in his equation. By the way, he must mean m^2 (metres-squared), not m (metres) in his equation.

To check this all made sense, I exported the table from SAM that shows number of heliostats in the various zones of the solar field, then used this with the "max distance from tower", "min distance from tower", and "radial step size for layout" to calculate the total area. For partially-filled zones at the outer radius (pink, not red in the SAM graphic), then I ratio-ed them. Adjacent zones at that same radius show the maximum heliostats for that radius, allowing me to know what fraction of the zone is full.

The "solar land area multiplier" inflates this "Area of Zones Occupied by Heliostats (m)". I guess this is to account for the fact that typically you don't buy a circular piece of land, so there is spare around the outside that is not suitable to use for "Non-Solar Field Land Area".