Technology Status - NET Nowak Energie & Technologie AG

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Despite the relatively low efficiency in power generation, geothermal has several
positive features. Geothermal electric plants can operate 24 hours per day and
thus provide base-load capacity. The power generation is not intermittent like
solar or wind - except for some seasonal differences in cycle efficiencies because,
in winter, heat is rejected to a lower sink temperature and thus the plant output
is higher. This is especially true for air-cooled binary plants.
A relatively new concept in geothermal power is Hot Dry Rock (HDR), also
known as Hot Wet Rock (HWR), Hot Fractured Rock (HFR) and Enhanced
Geothermal Systems (EGS). The basic concept is to increase the permeability
of the natural fractures of the basement rocks, install a multi-well system,
force the water to migrate through the fracture system (“reservoir”) by using
enhanced pumping and lifting devices and, finally, use the heat for power
production. HDR is expected to contribute to further geothermal
development in the decades to come.
● Costs
As for other renewable energy systems, the costs of a geothermal plant are
heavily weighted towards up front investments. The resource type (steam or
hot water) and temperature, as well as reservoir productivity, influence the
number of wells that must be drilled for a given plant capacity. Power plant
size (rated capacity) and type (single-flash, binary, etc.), as well as
environmental regulations, determine the capital cost of the energy
conversion system.
Investment Costs
According to US DOE the initial cost for the field and power plant varies from
USD 1,500 to 5,000 per installed kW in the U.S., USD 3,000 to USD 5,000 per kW
for a small power plant ( 5 MW), depending on the resource temperature and chemistry. In
Europe, costs vary from below € 1,000 to over € 10,000, depending on plant size
and location. The costs of HDR, which is still in the development phase, vary from
€ 16,000 to 18,000 per kW and are expected to fall to € 2,000 to 3,000 per kW
by 2010 according to European Commission estimates.
Costs vary greatly according to type of technology, size and resource. The
impact of resource temperature and plant size on the capital cost of binary
power plants as shown in Figure 46, range from USD 1,500 to USD 2,500.
This does not include exploration and drilling costs.
GEOTHERMAL POWER X6