BESS sizing software converts a target usable energy and power rating into a buildable battery design: the container count, the inverter and PCS pairings, and the augmentation plan that holds capacity flat as cells age. FluxPilot sizes AC-coupled and DC-coupled (DC-block) projects to your target MWh and MW at the point of delivery, not at the cell, so round-trip losses, auxiliary draw, temperature derate, and degradation are all in the number before you commit to a container count.
The point is to size to usable energy, not nameplate. Usable energy sits well below installed capacity once you account for the SOC window, round-trip efficiency, parasitic load, and fade, so a design sized on nameplate underdelivers on day one and falls further behind every year. FluxPilot keeps sizing, augmentation, weather, and site layout in one project file, so changing an architecture or an OEM battery updates every downstream number instead of breaking a web of spreadsheet formulas.
At utility scale, sizing is not a single multiplication of power by duration. The gap between the nameplate energy you install and the usable energy you can contract comes from a stack of derates that compound:
Get any one of these wrong and the container count is wrong. FluxPilot applies the full stack, so the installed energy it reports is the energy that survives the losses.
You give FluxPilot a target: usable energy in MWh, power in MW, and duration. It works backward to the installed energy and container count that deliver that target in operation, then pairs the containers with inverters or PCS at the right ratio. Because it sizes to power and duration together, the C-rate implied by, say, a 100 MW / 400 MWh four-hour system is carried through to the container and conversion sizing rather than assumed. The result is a defensible container count, not a round number you hope covers the losses. For the reasoning step by step, see the guide on how to size a utility-scale BESS.
FluxPilot sizes both from the same project. In AC-coupled designs it pairs battery containers with standalone PCS units and reports the count and ratio. In DC-coupled (DC-block) designs, where storage shares a DC bus with the inverter (common in solar-plus-storage), it sizes the block and the shared conversion accordingly. Keeping both in one file lets you compare container and inverter counts side by side instead of reconciling two spreadsheets that never quite agree. See what FluxPilot covers for the full capability set.
Lithium cells fade, so a system sized only for day one drops below its usable-energy target within a few years. FluxPilot models a 20-year augmentation schedule that holds usable energy flat as capacity degrades, reporting the container and inverter counts to add in each year. That schedule is part of the sizing, not a separate estimate bolted on afterward, so when you change cells or duration the augmentation plan moves with it. See augmentation explained for how the schedule is built.
Temperature drives two things sizing cannot ignore: auxiliary draw, because thermal management works harder when it is hot, and available capacity, because cells derate at temperature extremes. FluxPilot draws on roughly 20 years of climate data and evaluates the design against a typical year (TMY P50) and a hot year (P90). Sizing to the typical year alone underdelivers on the hot afternoons when the grid leans on the asset hardest, so the hot-year case sets the margin.
FluxPilot is built for the engineers who own the container count: developers and IPPs scoping utility-scale and solar-plus-storage projects, and EPC and engineering firms turning a contracted target into a buildable design. If you are the one who has to defend a container count through procurement and technical review, then live with it for 20 years of operation, this is the tool that produces it.
Sizing produces a design draft to iterate on, not a final drawing. Once the container and inverter counts are set, FluxPilot places them on your actual parcel: it imports the site DXF, arranges battery and inverter blocks in rows and clusters, generates access roads with realistic turning radii, routes MV feeders, and respects setbacks and exclusion zones, then exports the layout back to DXF. See BESS site layout software for that stage, or the FluxPilot overview to see how sizing, augmentation, weather, and layout fit together. To run it on your own project, book a demo.
It converts a target usable energy (MWh) and power (MW) rating into a buildable battery design, accounting for depth of discharge, round-trip efficiency, auxiliary load, temperature derate, and degradation. FluxPilot outputs container counts and inverter or PCS pairings.
Yes. FluxPilot sizes AC-coupled designs with standalone PCS units and DC-coupled (DC-block) designs that share a DC bus, and lets you compare container and inverter counts across both in one project.
Yes. FluxPilot models a 20-year augmentation schedule that holds usable energy flat as cells fade, reporting the container and inverter counts to add each year as part of the sizing.
Yes. It uses roughly 20 years of climate data and evaluates the design against a typical year (TMY P50) and a hot year (P90), because temperature drives auxiliary draw and capacity derate.
One project file that holds architecture, OEM equipment, augmentation, and weather, and carries the sized container count straight into DXF-based site layout. Change an input and every downstream number updates, so the count you sized is the one you place on the parcel.