What This Tool Calculates
Calculate what we know. Ask for what we don't. Never invent the rest. That principle drives every number this tool produces.
Module count follows directly from target DC capacity and module power — that part is arithmetic. String count, mounting-unit count and (optionally) pile count depend on configuration choices you enter (modules per string, modules per mounting unit, mounting system). Construction duration depends on productivity rates and crew counts you enter for each activity — the tool never assumes a rate on your behalf.
How To Use It
- Enter target DC capacity, module power, modules per string and modules per mounting unit.
- Choose a mounting system (single-axis tracker, fixed-tilt, or custom) if you want a pile estimate.
- For each construction activity, enter your own productivity rate and crew count.
- Review the per-activity duration, the sequential-total reference figure, and which activity is the likely schedule driver.
- Optionally set a target duration per activity to see how many crews would be required to hit it.
Engineering Principle
The calculation chain is deliberately linear and traceable: target capacity and module power give module count (rounded up to whole strings); string count and mounting-unit configuration give mounting-unit count; mounting-unit count and a piles-per-unit figure give an indicative pile count. Every step is a plain multiplication or division of numbers you can see — nothing is hidden inside a black-box coefficient.
For scheduling, each activity uses the same relationship: Daily Production = Productivity per crew × Crews, then Working Days = Quantity / Daily Production, rounded up to a whole day. Activities are evaluated independently — the tool does not model which ones can run in parallel or what must happen before what, since that requires site-specific sequencing logic outside a preliminary sizing tool.
Pile Assumptions Are Indicative, Not Structural
When a mounting system is selected, the tool prefills a piles-per-mounting-unit figure — 8 for single-axis tracker, 24 for fixed-tilt — clearly labelled “INDICATIVE AVERAGE”. The moment you type your own value, the label changes to “USER-DEFINED VALUE” so it's always obvious which kind of number you're looking at.
Real pile counts depend on the tracker/table manufacturer's structural design, row length, terrain slope, wind/snow loading and geotechnical conditions. Use the indicative figure for early go/no-go planning only — replace it with the structural engineer's number before it drives any procurement or cost estimate.
Formulas
Modules = ceil(Target Capacity / Module Power) rounded to whole stringsModule countMounting Units = ceil(Module Count / Modules per Mounting Unit)Mounting unitsPiles = Mounting Units × Piles per Mounting UnitIndicative pile countDaily Production = Productivity per Crew × CrewsDaily productionWorking Days = ceil(Quantity / Daily Production)Activity durationEngineering Notes
This is a fast preliminary planning tool — not Primavera P6, Microsoft Project, a contractual programme, a certified bill of quantities, or a cost estimate. It does not model activity dependencies, resource calendars, weather risk, permitting timelines or logistics constraints.
All rounding is transparent: string, mounting-unit and pile counts round up (a partial unit cannot be built), and the tool always shows the gap between your target DC capacity and the actual configured capacity after rounding, rather than hiding it.
For a sense of the scale of real projects this kind of planning supports, see the delivered project portfolio and construction management experience behind this tool.
FAQ
Can this tool tell me how many piles my project needs?
It can produce an indicative estimate once you select a mounting system (single-axis tracker or fixed-tilt) and it applies a preset piles-per-mounting-unit average — 8 for tracker, 24 for fixed-tilt. These are indicative averages for early planning, not structural design values. Actual pile count depends on the tracker/table manufacturer, structural design, terrain and geotechnical conditions, so the tool clearly labels the figure and lets you override it with your project's real number the moment you have it.
Where do the productivity rates (piles/day, modules/day) come from?
From you. This planner does not assume a universal productivity figure for any activity — pile ramming rate, crew count, structure assembly rate and so on are all inputs you provide, because they depend on equipment, crew experience, terrain and weather on the specific project. There is no hidden default.
Is the total duration shown a real construction programme?
No. Each activity's duration is calculated independently from its own quantity and productivity. The tool also shows a sequential total (summing every activity one after another) purely for reference, and explicitly does not represent an optimised, resourced construction programme with sequencing and dependencies — that requires proper scheduling software and site-specific logic.
Why does the tool ask for so many separate inputs instead of just MWp?
Because only module count follows directly and reliably from target capacity and module power. Everything past that — modules per string, modules per mounting unit, pile count per unit, crew productivity — depends on decisions and conditions specific to the project. The tool calculates what it can derive and asks for the rest rather than guessing.