Technology

800V DC

AC distribution was designed for one-way power from central generation. Distributed energy needs a different backbone.

The problem

Passive AC was never designed for distributed energy

Solar, storage, fleet charging, heat, and edge compute all want bidirectional, multi-source power. Layering AC/DC converters at every device multiplies loss, cost, and complexity.

Electrification: Fleets, heat, industrial processes moving from fuel to electricity. Every new load needs infrastructure.
AI load growth: GPU racks at 400 kW–1 MW make 54V distribution physically non-viable. 800V DC is the only path.
Grid congestion: Connection queues stretching years. The bottleneck is distribution, not generation.

The physics

Voltage is freedom

Higher voltage means lower current for the same power. Lower current means smaller conductors, less voltage drop, and fewer conversion stages between sources and loads. A shared DC bus is designed so generation, storage, and loads meet on one voltage plane instead of translating through AC at every endpoint.

Power electronics — not copper and iron alone — make medium-voltage-class DC distribution practical at commercial scale. The DC BUS is the physical backbone of that approach:The physical DC backbone. SST, BusWay, PCS, protection, and grid interface in one architecture — current flagship 800 V DC.

Architecture

What sits on the DC BUS

Components designed as one system — not a loose catalogue of AC gear.

Solid State Transformer (SST)
DC BusWay
Power Conversion System (PCS)
Protection, controls
DC arc protection — native DC arc detection, digital protection relays

Grid interface capabilities designed into the stack include:

Grid-forming PCS
Grid-following PCS
Export limiting
Dynamic connection management
Volt/VAR optimisation
Frequency response
Black start capability
Utility interoperability

Comparison

Why sites re-think the backbone

Illustrative architecture differences — not a product performance guarantee.

Factor	Shared DC bus	Legacy AC distribution
Conversion stages	Primarily at grid edge	Often 3–5 per DER path
Bidirectional flow	Native to architecture	Requires added inverters
Conductor sizing	Favoured by higher V / lower I	Larger for same power at lower V
Expansion	Tap onto common bus	New cable runs per load

Designing for 800V DC?

Talk with Joule Junction about architecture, scale, and site constraints.

Talk to Us DC BUS