BESS section configurations
How BESSLayout arranges DC blocks and PCS skids into sections.
A BESS sectionis a group of one, two, or four DC blocks and the PCS & MV skid that serves them.
How many DC blocks share a skid depends on duration. At shorter durations the power demand is higher, so each skid serves fewer blocks. The default pairing for each configuration is shown below. Either skid size (20 ft or 40 ft) works with any configuration — see Supported equipment for ratings, or set a specific size with the PCS config card.
Solo
Standalone DC blocks, never joined to a neighbor. Both orientations put one block on a 20 ft skid at either duration — the fallback tier for thin strips and leftover corners. Solo Centered is the exception: one centered skid feeds a block on each long side, so it sizes like a twin (40 ft @2h / 20 ft @4h).
The skid sits off the block's cable end, in line with the block.
The skid sits alongside the block's blind long side instead — a narrower footprint that fits strips the standard solo cannot.
One PCS & MV skid centered between two DC blocks, each block's cable end at the PCS section for a short cable run.
Twin
Two DC blocks per skid: a 40 ft skid at 2h, a 20 ft at 4h. The mirror and compact arrangements pair two twins around a shared aisle — each pair keeps its own skid. The centered arrangements put both twins on one 40 ft skid instead, and a 40 ft skid carries four blocks only at 4h, so those two are 4h only.
Two blocks joined on their blind long sides, doors facing outward both ways, skid beside the cable ends.
The same long pair with the skid alongside the doors instead of off the cable ends — a narrower footprint for tight sections.
Two blocks joined end-to-end on their blind short sides; cable ends face outward, skid along the long side.
Two long pairs mirrored around a central skid spine, sharing one aisle.
Two short pairs mirrored around central skids. Only the aisle is shared, never the skid.
Two end-to-end DC block pairs with a PCS skid row on each side. The narrowest twin layout — fits shallow sites.
Two long pairs on either side of one skid, cable ends facing it. One skid feeds all four blocks.
Two end-to-end DC block pairs sharing a single central PCS skid. More compact than Twin Short Compact.
Quad
Four DC blocks on one 40 ft skid — but only at 4h. At 2h those four blocks draw more power than a single skid can convert, so a Quad builds as Quad Split, with a skid on each DC row. The footprint stays available at both durations; only the skid count changes.
Four blocks on a single skid — one service perimeter, the densest single section.
A skid on each DC row, two blocks per skid — the 2h-capable Quad.
Two quads paired with their skids between them, sharing the central aisle.
Repeating quads whose skids sit in the mandatory gaps between DC bands, so the fire separation does double duty. Usually what Auto builds on open rectangular ground.
Two quads mirrored around a central skid spine, sharing the aisle.
Auto vs. forcing a configuration
On Auto the solver keeps the densest valid section per zone, which is why an irregular site shows a mix: quads in the open field, twins in a narrower arm, a solo in a corner. Forcing a configuration pins every zone to one arrangement — the right call when your project standardizes on a section design, and a quick way to see what that standard costs in capacity.
Your DC block configuration filters the list — forcing Twin hides the quad family, forcing Solo leaves only single blocks — and duration gates the one-skid sections (the quads and the centered twins), as noted above. Diagrams are drawn at 4h.
Reading a layout
The pale grey end on each DC block is its cooling and cable end; it always faces the skid or the outside of the cluster, never another blind side. Doors sit on the long sides facing an aisle. If every block traces to a skid and every door to open space, you are reading the layout the way the solver built it.