Geothermal Power Generation

Geothermal Energy
The Power Generation Method
Utilizing the Abundant Resources of Japan

What is Geothermal Power Generation?

It is a power generation method using hot water and steam produced by underground magma.

Flash Steam Power Generation

※Mouseover the images to show a explanation

Steam and hot
water separated.
Steam turbine-driven generator
produces electricity.
Steam condensation at low
condenser pressure improves the
power generation output.
Cooling tower cools the warm
water from condenser to
obtain cold water. The cold
water is pumped back to
condenser for cooling.

The geothermal fluid is taken out of the ground, separated into steam and hot water, and the steam is used to generate electricity.

Binary Power Generation

Binary power generation

※Mouseover the images to show a explanation

Steam and hot
water separated.
Separated steam
transfers its heat to
generate hot water.
Pressurized Hot water
transfers its heat to the
working fluid and
vaporizes it.
Vaporized working fluid rotates the
turbine. Turbine drives the generator
to produce electricity.
Condensation of working fluid at low
condenser pressure improves power
generation output.
The subcooled condensate is pumped
back to the evaporator.
Cooling tower cools the
warm water from the
condenser to obtain cold
water. The cold water is
pumped back to the
condenser for cooling.

The steam or hot water from the geothermal reservoir is used to vaporize a working fluid with lower boiling point. The vaporized working fluid then rotates a turbine to generate electricity. As the power is generated by a secondary working fluid, this method is called as Binary power generation.

Features of Binary Power Generation

Power Generation with Low Temperature Steam / Hot Water

Unlike flash power generation, with the use of lower boiling point working fluid, it is possible to utilize low temperature steam / hot water (<150°C) for power generation.
Existing Hot Spring Wells Can Be Used

It is possible to utilize an existing hot spring well as it can generate power even with a low-temperature heat source. This reduces the cost of drilling wells and shortens the construction period.

IWATEC’s Geothermal Power Generation Scheme
Utilizing Existing Hot Spring Wells
Working in collaboration with local community

IWATEC’s Geothermal Power Generation Scheme Utilizing Existing Hot Spring Wells Working in collaboration with local community

Uses of Hot Spring Well

01—Direct utilization of the heat from hot spring wells
02—Cascade utilization of the heat from hot spring wells

Benefits of Geothermal Power Generation

Constant Power Generation

Electricity can be generated throughout the year, and is attracting attention as a base load power source.
Reuse of Steam /
Hot Water

Steam / Hot water after generating power can be reused for bathing or greenhouse cultivation.
Low CO2 Emissions

Derived from natural energy sources, and no fuel combustion to generate electricity, so it emits less carbon dioxide than thermal power plants.