Step 1: Within the Project Design Environment, Click Design Goals on the left Navigation Bar.
Step 2: Enter Design Search preferences including Search Metric and Search Parameters.
Selection of the Search Metric
Users may use the drop-down on this page to select the Search Metric. The ultimate goal of the search engine is to find the system design that generates the maximum Yield, the maximum IRR or the minimum LCOE, depending on the user’s preference.
Parameters that are “checked” will be optimized over. This means the software will find the optimal value for this parameter within the constraints entered on the previous pages. When parameters are “unchecked”, additional user input fields open to allow fixed values to be entered. This means the software will design the system using the user-entered value or the closest possible value to the user-entered value. Note that processing time increases with increased number of parameters “checked”. To minimize processing time, it is advised to only optimize over the parameters desired. Users may also enter the minimum and maximum ranges over which the optimization engine will seek for solutions to save on computational time or to look for specific ranges.
The following search parameters may be fixed or optimized over:
Skew Angle – Skew is the angle offset (in degrees) in which one rack is offset from another. Sites with boundaries that are not perfectly aligned N-S or E-W can benefit from having some amount of offset from one rack to another so that the racks can follow the boundaries. For Fixed-Tilt systems, the skew angle is measured with respect to the Azimuth angle (positive angle represents clockwise rotation). For Tracking systems, the skew angle is measured with respect to the normal of the Azimuth angle (positive angle represents clockwise rotation).
Azimuth Angle – Azimuth is the E-W orientation of the entire array. For fixed-tilt systems, a 180 degree azimuth corresponds to South-facing modules and a 0 degree azimuth corresponds to North-facing modules. For tracking systems, a 180 degree azimuth aligns the tracker row in a North-South orientation. Optimizing over azimuth balances production, time-of-day PPA pricing, and construction feasibility on sites with irregularly shaped boundaries.
Row Spacing – Row Spacing is the distance (in feet or meters, depending on project units of measure) between each rack, center-line to center-line. Row spacing is related to Ground Coverage Ratio (GCR). Increasing row spacing decreases GCR and vice versa. Row spacing affects inter-row shading, cable and conduit quantities, circuit losses and also impacts the amount of PV that can fit within a given boundary.
DC/AC Ratio – The DC/AC ratio is the ratio of the total system module DC nameplate rating at STC to the total system inverter max AC nameplate rating.
System Size – System size is the total nameplate capacity of the plant may be specified as either DC System Size (in MW) or AC System Size (in MVA). DC System Size is the total of all module nameplate ratings at STC. AC System Size is the total of all inverter AC nameplate ratings at the max inverter AC output rating.
Step 3: Check the desired optional Add-Ons to be included in project results.
Sensitivity Plots (Package A) – This package includes six plots showing the sensitivity of the search metric (IRR or LCOE) to one of the following financial parameters: Land Cost, Loan Rate, PPA Rate, Nominal Discount Rate, Module Cost and Total Project Cost. Note that the generation of these plots takes considerable time because new models are run with alternate financial data to generate the sensitivity curves.
Sensitivity Plots (Package B) – This package includes up to five plots showing the sensitivity of the search metric (IRR or LCOE) to one of the following design parameters: Tilt, Azimuth, Skew, Row Spacing, DC/AC Ratio and AC System Capacity. Note that the generation of these plots takes considerable time because new models are run with alternate design data to generate the sensitivity curves.
Cost Estimate – This option generates an itemized Capital Cost Estimate in Excel format.
CAD Drawings – This option generates a layout drawing in .DWG format.
Shading File – This option generates a shading scene file in .DAE format which may be imported in PVsyst.
Step 4: Click Save. Data entered may be lost if not manually saved.