Australian Science Illustrated — Issue 54 2017

Power For 50,000 Homes

If everything goes according to plan, supercritical fluid from the new well can

generate electricity in a new turbine planned for the Reykjanes plant in a few years.

Steel and concrete
keep out soil

1

Supercritical fluid rises
through a plug with small
holes. The plug consists of a
combination of steel and concrete,
which make up the bottom of the
some 5-km-deep pipe leading up
to the power plant.

Pressure drop

produces hot vapour

2

The supercritical fluid is

directed into a chamber, in

which the pressure is eased. The

liquid gas turns into extremely

hot ordinary vapour – 4-600 °C as

compared to 300 °C for ordinary

vapour. Surplus water is pumped

back into the ground.

Vapour powers

powerful turbine

3 The hot vapour is directed into a turbine,

where it forces itself past rotor

blades, which are caused to

rotate. In the turbine, the

vapour transfers its energy to

the turbine blades, losing both

temperature and pressure.

Dynamo generates power

4

On the same shaft as the turbine, there is an

electric generator, also known as a dynamo. The

shaft is equipped with magnets, which produce a

rotating magnetic field. Around the field, electromagnets

convert the rotating magnetic field into energy (power).

Icelandic city's power
demand met

5 The power is distributed via the electricity grid.

Scientists estimate that one
geothermal well will generate
enough power for 50,000 homes.

Water is reused

6

When the vapour has

used up its energy in the

turbine, it condensates,

turning into water, which is

pumped back into the

ground. The water ends up

above the magma chamber to

be heated into supercritical

fluid again.

CLAUS LUNAU

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