**David R. Wunsch**

**State Geologist and Director**

**New Hampshire Geological Survey**

**Vice-President, Association of American State Geologists**

**Testimony Before the**

**Energy and Natural Resources Committee**

**U.S. Senate**

**September 26, 2007**

**Introduction**

Mr. Chairman and members of the Committee, thank you for the opportunity
to present testimony in full support of S.1543. I am the vice-president
of the Association of American State Geologists (AASG), which represents
the chief executives of the geologic agencies of the fifty states and
the commonwealth of Puerto Rico. The state geologists, and the
geological surveys they direct, collect geologic information, conduct
research, and disseminate this information by way of scientific reports,
maps, and other means. Collectively the state surveys represent one of
the largest centers of geological information in the United States, and
whose participation will be critical in assessing and exploring
geothermal resources for the nation.

S.1543 fills an important gap in the research and development of
geothermal resources in the United States, and would serve to remedy the
lack of programmatic support for the DOE geothermal program as defined
in the Energy Policy Act of 2005. Geothermal Energy is an untapped and
underutilized resource that could contribute immensely to our nation's
energy independence, economic growth, and quest for low-emission,
sustainable energy resources. Recently an interdisciplinary panel
affiliated with the Massachusetts Institute of Technology (MIT)
concluded that both conventional and engineered geothermal systems could
produce 100 gigawatts of electric energy for the United States in the
next 50 years. Their report (*The Future or Geothermal Energy, MIT*)
recommends that the time to enlist a comprehensive plan to develop the
nation's geothermal resources is now. S.1543 is a big step toward
integrating the resources of federal government agencies, national labs,
academia, and state agencies in performing a national assessment to
evaluate our nation's geothermal resources.

**The Range of Geothermal Energy Opportunities**

In the eyes of the public, geothermal energy is generally equated with
areas of concentrated hydrothermal activity in the western United
States, such as Yellowstone National Park. Large-scale geothermal
systems exploit high-temperature water sources, capitalizing on the
supercritical water and stream generated at relatively shallow depths,
and use its heat energy to turn turbines and generators that produce
electricity. In the past decade a more ubiquitous, low-temperature form
of geothermal energy has been commercially successful that utilizes the
constant temperature of the earth at very shallow depths. These
low-temperature geothermal heat pump systems, sometimes referred to as
geoexchange systems, are very efficient at heating and cooling, and are
regularly being used in large commercial buildings, military
installations, public buildings such as schools, and private homes.
Geoexchange systems can be installed literally anywhere, and offer
widespread access to geothermal resources.

Direct hydrothermal power generation, and geoexchange systems described
above represent the high and low-temperature end members of the
geothermal energy spectrum, respectively. However, there are several
applications of geothermal energy that exist between these temperature
regimes, and offer a tremendous opportunity for the development of cost
effective, low-impact energy sources that are viable in geologic
settings that are more geographically diverse. For example, in
tectonically stable regions of the nation, most geothermal resources are
non-hydrothermal and are more difficult to exploit using existing
technologies. Yet the potential for this type of "dry" geothermal energy
is enormous because its use is not restricted to hydrothermal activity
normally associated with tectonically active regions. Technology is
being developed to exploit non-hydrothermal geothermal energy reserves,
known as hot dry rock (HDR) reservoirs. These energy extraction
technologies work by tapping heat with deep boreholes drilled into a HRD
reservoir. Once boreholes are installed, water is injected into the HDR
reservoir to induce fracturing and increase the heat exchange capacity
of the reservoir. This artificial generation of fractures creates more
pore space and surface area for water cycled into the HDR reservoir to
absorb geothermal heat. Water heated by contact with the rock is then
extracted from the fracture system through a neighboring extraction well
and used to generate power in steam turbines. In typical HDR designs the
water is circulated on a closed loop and injected back into the fracture
reservoir once it has passed through the power plant. Hence, HDR
geothermal systems are nearly 100% emission free, introducing no wastes
into the environment. Some designs, such as binary systems, incorporate
a secondary organic fluid that is circulated in a closed loop system to
create the mechanical energy necessary to generate electric power at
temperatures below the boiling point of water (212^o^F).

Several countries, including Japan, Switzerland, Sweden, Germany, are
actively advancing HDR technology by research and development, or
operating demonstration power-generating systems using HDR technology.
The European Union currently has sponsored a demonstration site near
Soultz, France that has shown promising results. In Australia, private
enterprise is leading the way in actively developing the technologies
for constructing engineered HDR systems. And the U.S., through a HDR
project at Los Alamos National Lab, has also worked with this
technology. There are many areas of the country that may be viable for
exploiting these enhanced or engineered geothermal systems at depths
that are within the drilling range of current technology, including much
of the western United States.

Geopressurized geothermal resources consist of gas-saturated brines
contained in oil and gas reservoirs under anomalously higher
temperatures and pressures than would ordinarily be expected. There are
many producing regions in the U.S. that have geological formations that
exhibit these conditions. The U.S. Department of Energy conducted a
geopressurized-geothermal research program from 1975 to 1992. The
resulting work showed that wells with high brine flow rates could
produce natural gas as well geothermal heat energy as a byproduct that
could be used to produce electricity using a Hybrid Power System (HPS),
similar to the binary system described above. The brine could safely be
reinjected into the formation to enhance recovery efforts. To date,
geothermal resources related to oil and gas production remain largely
underutilized. The further development of the resource would benefit
from enhanced reservoir characterization, improved high-temperature and
high-pressure drilling, construction, and completion technologies, and
the development of high efficiency binary-cycle power systems. S.1543,
in Section 5, addresses these and other constraints that preclude the
active development of these geopressurized-geothermal resources, and
would promote research, development, demonstration, outreach and
education, and commercial application.

The use of direct heat applications of geothermal waters is a vastly
underutilized resource. Water need not be heated to boiling or
supercritical temperatures to produce economic benefit. Water
temperatures in the 100^o^F range can be used for aquaculture and
enhancing biogas production. Geothermal fluids in the 150^o^F range can
be used for direct heating green houses, buildings and homes, food
processing, curing fabricated cement, and other purposes. Direct heating
applications can also be co-generated from power plants that utilize
hydrothermal fluids. The New Mexico Bureau of Geology and Mineral
Resources has compiled an excellent description and examples of the wide
uses and range of applications based on ambient temperature of the
fluids. The publication (*Geothermal Energy in New Mexico, 2006*) is
attached to this testimony. Data compiled by the Southern Methodist
University estimates that much of the West, and select areas of the
eastern half of the country may have temperatures in the range to
accommodate the direct uses described above within 10 kilometers of the
surface, which is a depth currently attainable utilizing present
drilling and engineering technologies adapted form large-scale oil and
gas production.

**Comments Specific to Senate Bill**

The Association of American State Geologists strongly supports the
initiatives that would be authorized in S.1543 if it became law. The
Bill would charge the USGS, in cooperation with DOE, to conduct a
nationwide assessment of geothermal resources within the United States.
This assessment is overdue. The last comprehensive characterization of
geothermal resources was conducted by the USGS in 1978 (*USGS Circular
790*). Since then there have been clear advances in geophysical
exploration, including three-dimensional (3-D) imaging, and other
methods for enhanced subsurface characterization. Moreover, maps created
by different sources that show favorable areas for geothermal resources
are often not consistent, or they are presented at broad, national
scales. Thus, there is a need for a uniform, comprehensive national
dataset presented at a detailed scale.

Many state geologic surveys maintain the well record libraries for the
states, and conduct the majority of basic geologic mapping activities
that are being performed in their states with funding through the USGS
Cooperative Mapping Program. In addition, several state surveys are
either independently or through consortia investigating a variety of
geologic repositories for carbon sequestration. The geologic data being
compiled from these efforts could concomitantly provide valuable
information for characterizing geothermal resources. These basic data
are critical to identifying and characterizing the nature and extent of
low permeability formations in basins or basement, or low-grade
hydrothermal resources that could be candidates for engineered
geothermal systems.

For example, state geologic surveys often have a significant amount of
information on local geothermal resources that should be captured in the
national assessment. The Alaska State Geological Survey performed an
assessment in the early 1980's that is the primary source for analysis
and current prospecting. Therefore, the AASG believes it is imperative
that any nationwide assessment of geothermal resources should be
performed in cooperation with the state geological surveys, regional
volcano observatories, and other local agencies that have knowledge and
data within and among the states. The development of cooperative efforts
and programs should be clearly reflected in Bill 1543. In my own state
of New Hampshire, there is currently a bill being evaluated by our state
legislature (HB 415-FN) which would charge the New Hampshire Geological
Survey with conducting a geothermal assessment of the state. This would
include compiling available geophysical data that have become available
since a cooperative Department of Energy pilot well project was
completed in the 1970's. For our new assessment, we would also collect
new data and expand the database of bottomhole temperature measurements.
This statewide assessment could benefit from cooperative efforts,
technical support, and additional funding from federal agencies, and
would ultimately provide new and more comprehensive data, including
geochemical and radiometric analysis of granite, which is one assumed
source of higher heat-flow areas within the state. The statewide
assessment for potentially expanding geothermal energy use is consistent
with New Hampshire's goal of having 25% or its energy needs supplied
from renewable sources by 2025. Many states have their own agendas for
developing renewable or green energy supplies, so the time is
appropriate for establishing a cooperative federal program would assist
state efforts to compile scientific data that collectively will be a
critical component of any national assessment.

S.1543 assigns the USGS a deadline of 2010 for completing the geothermal
assessment, which may not afford enough time to coordinate the resources
available between federal and state agencies, or synthesize the
assessments that states may be conducting independently. This is
especially true if engineered geothermal systems are considered. Perhaps
2012 would be a more appropriate date, which would allow adequate time
to complete the assessment. It is important that the national assessment
be comprehensive and robust, because the nation would depend upon the
findings of this report to develop the full extent of its geothermal
resources. Just as important, a realistic and accurate assessment will
be critical in meeting the stated goal of having 20 percent of the total
US electrical energy production from geothermal resources by 2030.

Currently less than 1 percent of the energy the nation consumes is
created from geothermal sources, so the proposed goal of achieving 20
percent of total electrical production by 2030 from geothermal resources
is ambitious, especially if this number refers strictly to electrical
energy production, and does not consider improvements to efficiency. The
EIA reports that total energy demand is increasing in the United States,
and is expected to grow by 41 percent by 2030 (*EIA website,*
<http://www.eia.doe.gov/oiaf/aeo/pdf/trend_3.pdf> ). By comparison,
Australia has a smaller population than the US, and is farther along in
the development of HDR power. Private companies have applied for permits
for 116 areas, and can be expected to invest \$A 524 M (\$US 435 M) in
their projects in the next six years. But Australia has limited their
geothermal power expectations to 6.8% of its base load power needs by
2030.

In the case of the US power portfolio, the 20 percent goal may be a more
achievable if energy efficiency is included. For example, geothermal
heat pumps are the most energy efficient and environmentally friendly
method of heating and cooling homes. They are 48% more efficient than
gas furnaces and 75% more efficient than oil furnaces, and the increased
efficiency means reduction in greenhouse gas emissions. Installing a
heat pump system in a typical home is equal to planting an acre of trees
in terms of greenhouse gas reduction. For every 100,000 homes with
geothermal heat pump systems, foreign oil consumption is reduced by 2.15
million barrels annually, and electricity consumption is reduced by 799
million kilowatt hours annually. The more than 900,000 geothermal heat
pumps installed in the U.S. currently yield an energy savings equivalent
to taking 1,165,000 cars off the road, planting more than 346 million
trees, or reducing crude oil imports by 19.3 million barrels. If
geothermal heat pumps were installed in commercial, industrial, and
private residences nationwide, we could save several billion dollars in
annual energy costs, and significantly reduce demand for electricity.

**Summation**

The Association of American State Geologists fully supports the
initiatives and programmatic efforts being proposed in S.1543.
Geothermal Energy is an untapped and underutilized resource that could
contribute immensely to our nation's energy independence. The nation's
energy needs are expected to grow in the coming decades, and the
Congress should act now to support research, development, and
demonstration of geothermal energy resources and projects to meet the
nations energy needs, reduce our dependence on foreign energy sources,
and to ensure national security. New technologies, and advances in the
scientific understanding of the earth's subsurface make a variety of
geothermal applications viable for meeting part of the nation's energy
needs. The members of the Association direct the activities of the state
geologic surveys, who are willing and able partners that can assist the
US Geological Survey and the Department of Energy with assessing and
developing the nation's geothermal resources as defined in S. 1543.
Thank you.