SolarPILOT Queries

Dear Paul & Michael:

Would you kindly have a look to these queries on SolarPILOT functioning principles? I've read about the software in Michael's paper "SolarPILOT A Power Tower Solar Field Layout and Characterization Tool". I tried to order them by relevance.

1. Does SolarPILOT (analytical & MCRT methods) calculate tower shadowing over the heliostats?
2. Does SolarPILOT (analytical & MCRT methods) support non-rectangular heliostats?
3. Does SolarPILOT (analytical & MCRT methods) support heliostats with double tilt drives opposed to elevation-azimuth drives?
4. On the analytical method, cosine and attenuation losses are calculated at heliostat level and spillage loss (intercept factor) is calculated at optical zone level. Are shadowing and blocking losses calculated at heliostat or optical zone level? Is the list of neighbour heliostats used to calculate shadowing and blocking losses coincident with the optical zones? If the answer to both queries is affirmative, shadowing and blocking losses calculation inaccuracies could occur for heliostats placed at the boundaries of the optical zones.
5. On the analytical method, aiming strategy and Sun positions used when generating the dynamic heliostat grouping also called optical zones (used for evaluating the intercept factor derivatives)?

Thanks!

Javier Pastoriza.

Hi Javier,

1. No, SolarPILOT does not calculate tower shadows on the heliostat. You could could account for shadows by disabling heliostats that fall within the tower’s shadow either in the user interface or via scripting.

2. No, SolarPILOT only supports rectangular heliostats. Some initial work on round heliostats was started, but that work is not complete.

3. SolarPILOT does not support heliostats with double tilt drives.

4. As for the shadowing and blocking loss calculations, the optical zones are used only for intercept efficiency calculations done as part of the field layout calculations, and blocking, shading, and all other losses consider all possible neighboring heliostats. This method is used to assign a value of intercept efficiency to heliostats in a local region. Any potential inaccuracy by approximating the intercept factor of a local group of heliostats with a single value would only show up in the selection of heliostats included in the final layout; it would not affect the performance characterization of that field once layout is complete. In other words, intercept efficiency is evaluated for every heliostat separately when conducting performance calculations for a given layout.

5. For aiming strategy, layout calculations are done assuming all heliostats aim at the center of the receiver (“simple aim points”). The optical groups are determined once and are not updated based on sun position during layout calculations. Note that the use of the optical zone method can be disabled with the “Enable optical zone layout method” checkbox on the Layout Setup page of the SolarPILOT software interface. If you’d like to compare the layout with and without this method, it can easily be done by toggling this checkbox and regenerating the layout.

Best regards,
Paul.

I am working on SAM 2021 version but the problem I am facing is that when I selected a day like 22 Dec after simulation it is not matched for 2021 or 2022. My question is that how can I select the exact date of 2021/2022 to run the simulation for concern day? Thanks

Hi Thomas,

The specific date represented by the time stamp depend on the time stamps in the weather file. If you want to know what year the time stamp represents, you can look at the year column in the weather file.

Best regards,
Paul.

Thanks Paul for the comprehensive answer, great support.

Javier Pastoriza.