The “X per kWp” figures in circulation are a starting point, not a quotation. Two plants of the same capacity diverge sharply in cost depending on roof type, the amount of mounting steel, cable distance and inverter choice. SolarSimPro derives cost from the design itself: the layout defines the bill of materials, and the bill defines the cost.
Total DC capacity comes from the layout; module count and the chosen model are direct line items. On the inverter side, the DC/AC ratio and the number of inverters drive the cost.
On ground-mount sites the number of tables follows the row × module configuration; on roofs the length of mounting rail follows the module arrangement. In most budgets this is the second largest item after the modules.
DC cable follows the number of strings and the distance; AC cable cross-section follows each inverter's output current. A long route inflates the cost quietly.
Installation, excavation, earthing, monitoring and transport. Covering these with a flat percentage widens the error; they need to be tracked line by line.
The same 500 kWp produces different budgets on two projects. Sloping terrain increases mounting and excavation; a scattered roof lengthens cable runs; a high DC/AC ratio lowers inverter cost but introduces clipping losses. A single multiplier sees none of this.
A rule-of-thumb figure is fine for a rough feasibility check. In a quotation handed to a client, the error comes straight out of your margin.
Once the layout exists, the module count, DC capacity, table quantity and cable route are already determined. The bill of materials is extracted from that geometry automatically, multiplied by the unit price database, and a line-by-line cost summary appears.
When you change the design — row spacing, module model, inverter count — the cost updates in the same pass. There is no separate spreadsheet to feed by hand.
Cost is not a separate exercise; it is an output of the design workflow.
The ranges quoted in the market are a rough starting point and deviate sharply with site conditions. A sound figure comes from applying your own unit prices to your own design's bill of materials.
Yes. The database prices are defaults; when you replace them with your supplier prices, the summary and the feasibility update together.
It does. The investment figure is used directly in payback, net present value and internal rate of return; you do not need to transfer it.
On ground-mount sites, tables, excavation and long DC routes dominate; on roofs, mounting rail and installation labour come to the fore. Both flows are calculated in the same program with their own line items.
Generate the layout and let the bill of materials and cost summary build themselves. Runs in the browser, no installation.