HIGHLAND UTILITIES TRUSTNORTHERN GRID AUTHORITYSEABOARD POWER BOARDINTERIOR TRANSMISSION CO-OPCOASTAL MUNICIPAL POWERESTUARY ENERGY BOARDHIGHLAND UTILITIES TRUSTNORTHERN GRID AUTHORITYSEABOARD POWER BOARDINTERIOR TRANSMISSION CO-OPCOASTAL MUNICIPAL POWERESTUARY ENERGY BOARD
One machine, three hard problems.
Confinement, fuel and heat. Every programme in this field dies on one of the three, so we built for all three at once.
The field
Twenty tesla of rare-earth tape, wound cold, holding the plasma off the wall.
The fuel
Deuterium and tritium, bred in a lithium blanket, accounted for gram by gram.
The heat
Neutron heat into a salt loop, out through a turbine, onto somebody's grid.
150 MK
core ion temperature at the last shot
20.4 T
peak field at the magnet face
30.4 s
longest burn on the record
The plasma has a shape.
Each ring is a surface of constant pressure. Get the shape wrong and the plasma finds the wall inside a second, taking a first-wall tile with it.
Shape control
Two hundred coil currents, re-solved every four milliseconds.
Wall margin
Ninety millimetres between the last closed surface and the tile.
Flux surfaces, shot 12,880
Five gates, in order.
Net heatSteady stateFuel loopFirst powerSecond plant
01
Net heat
More energy out of the plasma than we put into it. Every programme in the field is measured against this one number, including ours.
02
Steady state
A shot that ends because we ended it, and not because a coil warmed through or a first wall ran out of margin.
03
Fuel loop
The blanket has to breed tritium faster than the plasma burns it. Nothing about a plant closes until that ratio passes one.
04
First power
The turbine house comes up and the first megawatt-hour leaves the site through a meter somebody else reads.
05
Second plant
The same machine again, built from drawings rather than from physics, at half the cost and twice the pace.
What sits in the hall.
Magnet set
Sixteen D-shaped coils, wound from rare-earth tape and held at twenty kelvin.
20.4 tesla peak
20 K bore
Vacuum vessel
A double-walled torus pumped to a ten-billionth of an atmosphere.
9.4 m across
316LN steel
Breeding blanket
Flowing lithium salt that catches the neutrons and makes the tritium back.
1.08 breeding ratio
Molten salt
Heating drive
Gyrotrons and neutral beams that take the plasma from cold to burning.
32 MW installed
170 GHz
Control room
Forty thousand diagnostic channels, and one solver reading all of them.
4 ms control loop
Triple redundant
Power island
Steam plant, switchyard, and the meter the offtake contract is read from.
412 MW thermal
148 MW firm
HIGHLAND UTILITIES TRUST
148 MWfirm power already contracted from the first plant
We have signed for power that does not exist yet. What made it signable was the shot log, not the renderings.
Helen Vance · Director of generation, Highland Utilities Trust
What power costs.
Three ways to buy it: a share of the pilot, firm baseload out of the first plant, or the plant itself on your own site.
