20 ft DC block — Configuration and site layout options
The 20 ft liquid-cooled DC block — dimensions, energy capacity, mirror variants, service clearance, and stacking options.
Overview
The most common 20-foot liquid-cooled DC block topology. One long side has service doors for battery module access and replacement. The opposite long side and one short side are blind sides — no clearance required. The remaining short side is the cooling and cable end, where the liquid cooling unit and DC cable entry are located. This is the default configuration in the BESSlayout solver.
| Parameter | Default |
|---|---|
| Container length | 6.058 m |
| Container width | 2.438 m |
Each side has a role: one long side carries the service doors, the opposite long side is blind, one short side houses the cooling and cable end, and the opposite short side is also blind. These roles determine which sides can face inward when blocks stack.
Energy capacity & duration options
The 20-foot DC block is available in several energy capacity configurations. The duration rating defines how long the block can sustain a full charge or full discharge at rated power — a 2-hour system fully charges or discharges in 2 hours, a 4-hour system in 4 hours.
Both energy capacity and duration are preset in the solver by default. Users can select their preferred combination in the DC block configurator.
| DC block | Energy | Duration |
|---|---|---|
| 6.25 MWh | 6.25 MWh per DC block | 2h or 4h |
| 5 MWh | 5.016 MWh per DC block | 2h |
Mirror variants (A and B)
Each DC block comes in two mirror variants. The cooling and cable end stays on the same short side in both — the mirror swaps which long side carries the service doors. This makes it possible to pair A and B variants in different stacking configurations.
This lets two blocks pair with their doors facing outward and their blind long sides touching, which is how every Twin Long and Quad cluster is built. The solver places A/B pairs automatically — there is no manual selection.
DC block stacking options
Since each DC block has two blind sides — one long and one short — blocks can be stacked against each other on either side with a clearance gap in between. The gap distance varies by manufacturer and may be driven by fire safety requirements.
Four stacking options are available:
- Solo — a single DC block.
- Twin Long — two blocks stacked on the long blind side.
- Twin Short — two blocks stacked on the short blind side.
- Quad — four blocks stacked on both the long and short blind sides.
The DC block configurator defaults to Auto, which selects the highest-density option. Users can override this to use a specific stacking option — for example, to meet fire safety separation requirements or to control energy density on the site.
Service clearance requirements
Each DC block requires service clearance on two sides: the long side with service doors and the short side with the cooling and cable end. The two blind sides require no clearance.
The service door side requires clearance to open doors and remove or replace battery modules. The cooling and cable end requires clearance for accessing and replacing the cooling unit, as well as sufficient distance for ambient air intake.
Default clearance values are preset in the solver but can be adjusted in the DC block configurator, as different manufacturers may specify different requirements.