Staying Positive – Producing Net Power

• Jack Acres
• Ioannis Antoniou
• Finley Christie
• Daniel Blackburn
• Samuel Knight

The STEP Prototype Powerplant (SPP) will be a first of a kind powerplant – its prime objective is to export electrical power, to the grid, above 100MWe. As part of a wider issue, addressing the STEP concept design, this paper seeks to explore how electrical power will be generated from a Spherical Tokamak heat source. Accordingly, the following key functions of the SPP Power Infrastructure, are reviewed:

• Cool the tokamak: Cooling of the tokamak while extracting useful thermal energy.
• Generate power: Conversion of thermal energy to electrical energy (power generation)
• Manage energy: Management of the site-wide distribution, storage, and energy export.

In each of these areas the design scope, challenges, and solution spaces have been discussed. This has shaped the design of the SPP Power Infrastructure, which in turn has ensured a powerplant design focused on operability and performance. Furthermore, it has been demonstrated that the SPP will achieve its prime objective in generating net power, which is enabled by a unique Power Infrastructure. Confidence in the ability to generate net power will be refined as the design matures. Finally, this paper recommends key opportunities that STEP could utilise to improve power generation and reduce the parasitic load of the SPP.