Direct-Energy-Conversion Efficiency Gate

MetroVolt replaces the steam turbine with direct energy conversion; whether it reaches useful efficiency at scale is a design-stage gate.

Turning particles straight into current

Direct energy conversion (DEC) captures the kinetic energy of charged fusion products and decelerates them against an electric field, delivering current without a thermal cycle. In a D-³He burner, most fusion energy appears in charged particles, which makes DEC attractive — and makes its efficiency central to the machine’s value.

The gate is whether DEC reaches a useful conversion efficiency in an integrated machine, handling the real particle spectrum, space-charge limits, and thermal loads on the collector. The approach is specified and simulated; it is at design stage, not demonstrated at generator scale.

Why DEC matters for MetroVolt specifically

DEC is the reason MetroVolt needs almost no water: with no steam cycle there is little to cool by evaporation. It is also central to net electric output, since conversion efficiency directly sets how much of the fusion power reaches the grid. A DEC shortfall would weaken both the water story and the power story.

• Captures charged-particle energy without a turbine.
• Removes the steam cycle — hence the small water footprint.
• Efficiency at scale is a design-stage gate, measured on the test unit.