Geothermal Technologies Program

Buried Treasure

The Environmental, Economic, and 

Employment Benefits of Geothermal Energy
As charged by Secretary Abraham, the Offi ce of Energy Effi ciency 

and Renewable Energy provides national leadership to revolutionize 

energy effi ciency and renewable energy technologies, to leapfrog the 

status quo, and to pursue dramatic environmental benefi ts. 

The Geothermal Technologies Program, a critical part of our overall 

effort, is making great strides toward increasing the viability and 

deployment of geothermal heat and power. The peer reviewed, 

focused R&D and supporting outreach activities conducted by this 

program will enable broad expansion of the use of geothermal 

resources throughout the western United States. Through federal 

leadership and partnership with states, communities, industry, and 

universities, we will ensure that geothermal energy is established as 

an economically competitive contributor to the U.S. energy supply. 

Our program’s success will mean a stronger economy, a cleaner 

environment, and a more secure energy future for our nation.

David K. Garman

Assistant Secretary

Energy Effi ciency and Renewable Energy

“Pursuing a prosperous future 

where energy is clean, abundant, 

reliable, and affordable....”

Cover image: People enjoy the geothermal, hot spring pools in Yellowstone National Park, Wyoming. 

PIX 03698 Warren Gretz, NREL 
About Geothermal Energy 

The geothermal energy potential beneath our feet is vast. This tremendous resource amounts to 

50,000 times the energy of all oil and gas resources in the world. And geothermal energy is clean; 

it represents a promising solution for the nation and the world as we become ever more concerned 

about global warming, pollution, and rising fossil energy prices. Furthermore, increased development of 

geothermal energy gives people the potential to gain better control of their own local energy resources and 

use a secure, safe, domestic source of energy.

There are three primary ways we can use geothermal energy: for electricity production, for direct-use 

applications, and for heating and cooling buildings with geothermal heat pumps.

Electricity Production

Electricity production using geothermal energy is based on conventional steam turbine and generator 

equipment, in which expanding steam powers the turbine/generator to produce electricity. Geothermal 

energy is tapped by drilling wells into the reservoirs and piping the hot water or steam into a power plant 

for electricity production. The type of power plant depends on a reservoir’s temperature, pressure, and fl uid 

content. There are three types of geothermal power plants: dry-steam, fl ashed-steam, and binary-cycle 

(see Figure 1 on page 2 for more information).

Direct Use

Hot water from geothermal resources can be used to provide heat for industrial processes, greenhouses, 

crop drying, heating buildings, or even melting snow on sidewalks and bridges. This is called “direct use.” 

A well is drilled into a geothermal reservoir to provide a steady stream of hot water. The water is brought up 

through the well, and a mechanical system—piping and pumps, a heat exchanger, and controls—delivers 

the heat directly for its intended use. 

Geothermal Heat Pumps

Geothermal heat pumps (GHPs) use the shallow ground—which maintains a nearly constant temperature 

between 50° and 60°F (10°–16°C)—as an energy storage device. GHPs transfer heat from a building to 

the ground during the cooling season, and transfer heat from the ground into a building during the heating 

season. GHPs marketed today also can provide hot water. 

A Buried Treasure of Environmental, Economic, and Employment Benefi ts

Together, all of these geothermal technologies are a winning combination for cleanly meeting our country’s 

energy needs. Many U.S. communities and individuals benefi t environmentally from using geothermal 

energy. And geothermal energy resources are domestic resources. Keeping the wealth at home translates to 

more jobs and a more robust economy. 

This publication further explores the environmental, economic, and employment benefi ts of geothermal 

electricity production and geothermal direct-use. 

Contents

Environmental Benefi ts and Impacts of Geothermal Energy

Geothermal Power Plants

Meeting Clean Air Standards

Minimizing Solid Waste and Recovering/Recycling Minerals

Meeting Water Quality and Conservation Standards

Minimizing Land Use and Impact 

Geothermal Direct-Use Applications

Economic and Employment Benefi ts and Impacts of Geothermal Energy

Economic Impacts

Economic Impact of Geothermal Greenhousing

Employment Benefi ts

California Job Growth from Geothermal Development

References

2

10

14

1
Dry-steam power plants

draw from underground reservoirs 

of steam. The steam is piped directly 

from wells to the power plant, where 

it enters a turbine. The steam turns 

the turbine, which turns a generator. 

The steam is then condensed and 

injected back into the reservoir 

via another well. First used in Italy 

in 1904, dry steam is still very 

effective. The Geysers in northern 

California, the world’s largest single 

source of geothermal power, uses 

dry steam.

Flashed-steam power plants

tap into reservoirs of water with 

temperatures greater than 360°F 

(182°C). This very hot water flows 

up through wells under its own 

pressure. As it flows to the surface, 

the fluid pressure decreases and 

some of the hot water boils or 

“flashes” into steam. The steam is 

then separated from the water and 

used to power a turbine/generator 

unit. The remaining water and 

condensed steam are injected 

through a well back into the reservoir.

Binary-cycle power plants 

operate with water at lower 

temperatures of about 225° to 360°F 

(107° to 182°C). These plants use 

heat from the geothermal water 

to boil a working fluid, usually an 

organic compound with a lower 

boiling point. The working fluid 

is vaporized in a heat exchanger 

and the vapor turns a turbine. The 

water is then injected back into the 

ground to be reheated. The water 

and the working fluid are confined 

in separate closed loops during the 

process, so there are little or no air 

emissions.

Environmental Benefits 

and Impacts of 

Geothermal Energy

All energy development and production impacts the environment to some 

degree. But the use of geothermal energy 

can greatly minimize these impacts, 

resulting in environmental benefits for 

many states and local communities with 

growing energy needs. 

Geothermal energy is clean, sustainable 

energy. Also, most geothermal energy 

development postdates the passage of 

the National Environmental Policy Act 

in 1970. Therefore, the geothermal 

industry has grown up in an age of higher 

environmental awareness. As a result, the 

use of geothermal energy helps keep our 

air and water clean. Its use also greatly 

minimizes the amount of resulting solid 

waste and land required for energy 

production. The U.S. Department of 

Energy (DOE) works closely with its 

geothermal industry partners to further 

reduce any environmental impacts from 

geothermal operations—from power 

plants and direct-use applications. 

Geothermal Power Plants

Power plants operating in the United 

States have to meet many federal, state, 

and local environmental standards and 

regulations, such as the Clean Air Act. 

Local communities have shown that use 

of their geothermal resources to generate 

electricity can easily meet or surpass these 

standards and regulations (see The AwardWinning Environmental Performance of 

Geothermal Power in California on page 6). 

Figure 1. Types of Geothermal Power Plants

2 

Meeting Clean Air Standards 

Geothermal power plants can meet the 

most stringent clean air standards. They 

emit little carbon dioxide, very low 

amounts of sulfur dioxide, and no nitrogen 

oxides (see Charts 2 and 3 on page 4). 

To put this in perspective, electricity 

produced from U.S. geothermal resources 

million metric tons of carbon dioxide, 

200,000 tons of sulfur dioxide, 80,000 

tons of nitrogen oxides, and 110,000 

tons of particulate matter compared to 

conventional coal-fired plants.

annually offsets the emission of 4.1 
The small quantities of gases emitted 

from geothermal power plants aren’t 

created during power production (there’s 

no combustion) but are natural, minor 

constituents of all geothermal reservoirs. 

These gases eventually would vent to the 

atmosphere without geothermal power 

development, although at much slower 

rates. Dry-steam and flashed-steam plants 

emit mostly water vapor. Binary-cycle 

power plants emit virtually no gases 

because they operate using a closed-loop 

system. See Figure 1 on page 2 for more 

information on how these types of plants 

operate. 

When geothermal power plants do emit 

gases, it’s mostly carbon dioxide, which 

isn’t a pollutant but a greenhouse gas. But 

geothermal power plants emit much less 

carbon dioxide than fossil fuel power 

plants. See Chart 1.

Also, the common practice by geothermal 

power plants to inject geothermal fluids 

back into reservoirs to sustain resources 

has diminished their carbon dioxide 

emissions. Carbon dioxide emissions 

from the Dixie Valley geothermal “flashedsteam” power plant in Nevada decreased 

from 0.152 pounds per kilowatt-hour 

(kWh) in 1988 when it didn’t use this 

practice to 0.093 pounds per kWh in 1992 

when it did. That’s a 39 percent reduction. 

The Coso Operating Company in 

California has experimented with injecting 

carbon dioxide back into geothermal 

injection wells—another practice that may 

hold some promise for preventing carbon 

dioxide emissions altogether from drysteam and flash-steam plants. 

There currently aren’t any federal carbon 

dioxide emission limits. However, 

geothermal power plants help support 

the Bush Administration’s 2001 National 

Climate Change Technology Initiative, 

which was established to strengthen 

technology research and development 

(R&D) related to climate change. The 

initiative included tax incentives for the 

use of renewable energy in buildings and 

for electricity generation.

Gases released from geothermal fluids 

may also include hydrogen sulfide, which 

causes the characteristic sulfurous odor 

often evident near natural hot springs. But 

typical emissions of hydrogen sulfide from 

geothermal plants are less than 1 part per 

billion—well below what people can smell. 

PIX 07658, Joel Renner, INEEL

This geothermal steam power plant in Steamboat Springs, Nevada, emits mostly water vapor.

3
In fact, most geothermal power plants 

produce such low concentrations of 

hydrogen sulfide that they require no 

special controls to comply with most state 

and federal emission standards. At The 

Geysers in California, the steam contains 

up to 0.15 percent hydrogen sulfide by 

weight, but treatment processes remove 

more than 99.9 percent of emissions.

As a result of the efficiency of the 

hydrogen sulfide treatment processes 

at The Geysers, Lake County became 

the first and only county in compliance 

with California’s stringent air quality 

regulations in 1990. The State of 

California has also honored Pacific Gas 

& Electric Company (initial owner) and 

Calpine Corporation (present owner) 

for pollution prevention at The Geysers 

(see The Award-Winning Environmental 

Performance of Geothermal Power in 

California on page 6).

DOE laboratories continue to investigate 

even more efficient processes for detecting 

and treating gases and particulate 

matter produced by geothermal plants. 

The Idaho National Engineering and 

Environmental Laboratory has developed 

a new monitoring system that uses laser 

technology for the real-time detection of 

gases and particulates in process streams. 

The system can measure hydrogen sulfide 

levels at the part per million (ppm) 

level, and it may also help warn about 

equipment corrosion. 

Minimizing Solid Waste and 

Recovering/Recycling Minerals 

Although many geothermal plants 

generate no appreciable solid waste, the 

unique characteristics of some geothermal 

fluids require special attention to handle 

entrained solid byproducts. Interestingly, 

these solid byproducts often contain 

valuable minerals that can be recovered 

and recycled for other industrial uses.

At the Salton Sea plants in southern 

California, the mineralized geothermal 

brine contains enough corrosive salts and 

heavy metals to require special disposal. 

To remove the heavy metals, the plants 

dewater the waste stream. The salts are 

crystallized and removed. The remaining 

solids contain mostly silica, which 

is removed for use as a valuable raw 

material in several industrial processes. 

4 
Valuable minerals and metals can even 

be recovered via the hydrogen sulfide 

treatment systems at The Geysers in 

northern California. One system converts 

the hydrogen sulfide into elemental sulfur, 

which is recycled for use as a feedstock for 

sulfuric acid production. 

Meeting Water Quality and 

Conservation Standards

U.S. geothermal power plants use cooling 

towers or air-cooled condensers to reject 

waste heat into the atmosphere. Therefore, 

they, unlike most fossil fuel and nuclear 

power plants, dump no waste heat into 

rivers or surface water. Waste heat disposal 

can disrupt biota—such as algae and fish—

in local water bodies.

Technology for the safe, nonpolluting 

use of geothermal fluids has been 

carefully developed and rigorously tested. 

Geothermal production and injection 

wells are lined with steel or titanium 

casing and cement to isolate fluids from 

the environment, including groundwater. 

Repeated examination—using sonic 

logging instruments and videography—

of the casing and cement ensures that no 

leakage occurs. Spent geothermal fluids 

are then injected back into the reservoirs 

from which they were drawn. This solves 

the fluid disposal problem, and it prolongs 

the use of the geothermal reservoirs 

because it replenishes fluids.

The Lake County Sanitation District in 

northern California found that injecting 

effluent from its wastewater treatment 

facility into several wells connected to 

The Geysers geothermal reservoir was 

environmentally superior to conventional 

surface disposal methods, such as surface 

water discharge or land irrigation. Rising 

production shows that this effluent 

injection also helps replenish the steam 

resource at The Geysers, which was 

diminishing prior to this process. In 

addition, it has reduced the amounts of 

noncondensable gases, including hydrogen 

sulfide, in the steam. The recycling of 

wastewater for extending the life of the 

geothermal reservoir helps conserve water 

resources in this arid region too.

To conserve water, especially in arid 

regions, geothermal power plants can use 

air instead of water to condense spent 

steam/turbine exhaust fluid for injection 

back into the reservoir. DOE researchers 

continue to work on ways to improve the 

efficiency of air-cooled condensers. The 

low profiles of air-cooled plants also blend 

in well with scenic areas (see the Hawaii 

Puna photo on page 6). 

Minimizing Land Use and Impact 

The western United States not only features 

some of the most beautiful scenery—from 

snow-capped mountain ranges to desert 

sunsets and ocean views—but also the 

country’s greatest potential for geothermal 

power. And geothermal power plants are 

compatible with these scenic, fragile areas. 

Geothermal power plants have small 

footprints; that is, they require little land 

compared to coal and nuclear power plants. 

An entire geothermal field uses 1-8 acres 

per megawatt (MW) versus 5-10 acres per 

MW for nuclear operations and 19 acres 

per MW for coal. Coal power plants also 

require huge acreages for mining their 

fuel. These mining operations can involve 

the large-scale movement of earth for 

construction of underground mine shafts 

and tunnels, waste heaps, and/or open 

pits. In areas disturbed by open pit mining, 

plants have a difficult time participating in 

the carbon cycle and evapotranspiration, 

which replenishes water in the atmosphere. 

Adequate remediation of strip-mined areas 

can be expensive too. 

A typical geothermal power plant requires 

wells, and drilling them impacts the land. 

However, advanced directional or slant 

drilling technology has evolved, which 

minimizes the impact. This drilling 

technology allows several wells to be 

drilled from one location, reducing the 

amount of land needed for drilling pads, 

access roads, and geothermal fluid piping. 

For geothermal exploration, slimhole 

drilling—developed by DOE’s Sandia 

National Laboratories—can be used to 

minimize environmental impact. Slimhole 

wells are only 4” to 6” in diameter while 

traditional geothermal exploration wells 

are 8” to 12” in diameter. Slimhole drilling 

also reduces the amount of land needed for 

site preparation and road construction.

Land subsidence can occur following 

the withdrawal of large amounts of 

fluid—water, oil, and even geothermal 

fluid—from beneath the earth’s surface. 

The common practice by geothermal power 

plants to inject spent geothermal fluids 

back into reservoirs to sustain resources 

helps prevent subsidence from occurring. 

Induced seismicity or earthquake activity 

becomes a concern when large amounts 

of geothermal fluids are withdrawn and 

injected below the earth’s surface,

The Salton Sea’s geothermal resource not only 

produces electricity in southern California but 

also silica—a raw material used in several 

industrial processes—which is recycled from 

its solid waste. 

Geothermal power plants use cooling towers, 

like these at The Geysers, to safely reject 

waste heat into the atmosphere.

PIX 08996, Geothermal Resources Council PIX 01044, David Parsons, NREL

5
especially in areas with a high frequency 

of naturally occurring seismic events. If 

induced seismicity occurs, it’s typically 

less than magnitude 2.5 on the Richter 

scale (earthquakes usually aren’t felt 

below 3.5). Recently, some areas 

near The Geysers geothermal field 

in California have been experiencing 

increased seismic activity. There’s concern 

that it could be due to the wastewater 

injection—which has helped replenish 

the geothermal resource—from the Lake 

County Sanitation District. DOE, the U.S. 

Geologic Survey, and the geothermal 

power companies at The Geysers are 

monitoring this activity.

Because of their minimal land use and 

impact, geothermal power plants blend in 

harmoniously with a variety of other land 

uses. For example, once the power plant 

and associated wells are completed, the 

land can be used for livestock grazing or 

other agricultural purposes. The Imperial 

Valley of southern California hosts 15 

geothermal power plants producing more 

than 400 MW of electricity within one 

of the most productive agricultural areas 

in the world. One of these plants—at 

the southern end of the Salton Sea—is 

neighbor to a national wildlife refuge 

that shelters hundreds of animal species. 

Visitors to Mammoth Lakes, California, 

enjoy many outdoor activities without 

This 30-MW, air-cooled geothermal power plant on the Big Island of Hawaii (Puna) blends in 

well with the natural landscape. 

Mammoth Pacific L.P.

For more than a decade now, 

three power companies and 

one community in California 

have received awards for their 

outstanding environmental 

performance from the use of 

geothermal power. Here’s a 

timeline of their award-winning 

performance, which can be 

expected to continue for many 

decades to come. 

1990

Pacific Gas & Electric Company 

received California’s first Air 

Pollution Reduction Award for 

minimizing hydrogen sulfide 

emissions at The Geysers. 

1990 – 2004

Lake County—home to five of 

The Geysers power plants—has 

been the only California air 

district to attain all state ambient 

air quality standards for more 

than a decade. 

1991

The California State Assembly passed a 

resolution commending Mammoth Pacific on 

the start-up of two of its geothermal power 

facilities in Mono County, recognizing its use 

of clean energy without “environmentally 

damaging emissions.” 

even noticing the geothermal power plant 

in the area, which was designed to blend 

into the landscape. In areas with natural 

hot springs and steam vents, proper siting 

of injection and production wells can 

minimize any impact to these scenic and 

recreational attractions. 

Mammoth Pacific was honored as a recipient of the 2003 Governor’s 

Environmental and Economic Leadership Award in California. Shown here 

from left to right: actor Beau Bridges, Secretary for Resources Agency Mike 

Chrisman, Larry Nickerson and Bob Sullivan of Mammoth Pacific, Governor 

Arnold Scharzenegger, Cal/EPA Secretary Terry Tamminen, and Department of 

Food & Agriculture Secretary A.G. Kawamura.

2000 – 2004

For four consecutive years, Mammoth Pacific 

has received from the California Department 

of Conservation an award for its outstanding 

environmental record at its Mono County 

geothermal facilities.

2002 – 2003 

Calpine Corporation—for 

its geothermal operations 

at The Geysers—received 

environmental and safety 

performance awards from 

the California Department of 

Conservation, which praised 

the company for air quality 

improvement and pollution 

prevention.

2003

Mammoth Pacific, for its 

Mono County geothermal 

facilities, received the 

Governor’s Environmental and 

Economic Leadership Award, 

which recognizes the use of 

innovative technologies to 

improve environmental quality 

and protect public health and 

safety.

2004

For its geothermal operations at The Geysers, 

Calpine Corporation received the Clean Air 

Award for Technology Development from the 

American Lung Associations of the Bay Area.

The Award-Winning Environmental Performance of Geothermal Power in California

Geothermal Education Office

6 
Geothermal Direct-Use 

Applications

Most geothermal direct-use applications 

impact the environment to a lesser degree 

than large-scale, geothermal power plants. 

This can benefit states, local communities, 

agribusinesses, and other industries that 

need these resources. 

Geothermal fluids vary from resource to 

resource, but the low- to mid-temperature 

geothermal fluids used for direct-use 

typically contain lower levels of gases 

than the higher temperature fluids used 

for power production. Today, most 

geothermal direct-use applications 

circulate these fluids through closed-loop, 

emissions-free systems. See Figure 2 for 

an example of how such a system works. 

The carbon dioxide found in geothermal 

fluids could prove beneficial to direct-use 

greenhouse applications. Carbon dioxide 

is a very effective growth stimulant 

for plants. Studies have shown that an 

increase in carbon dioxide from a normal 

level of 300 ppm to approximately 1,000 

ppm can raise crop yields up to 15 percent. 

Therefore, some researchers suggest that 

geothermal greenhouse heating systems 

could utilize the carbon dioxide present 

in the fluids if they find a way to remove 

any hydrogen sulfide, which can damage 

plants. Most geothermal fluids usually 

contain low, non-hazardous levels of 

hydrogen sulfide. 

Table 1. Primary Federal Environmental Regulations Governing Geothermal Energy Development

Laws & Regulations Air Surface

Water

Geothermal

Fluids

Solid

Waste

Liquid

Waste

Noise Subsidence/

Seismicity

Cultural

Resources

Biological

Resources

Federal Water Pollution 

Control Act (NPDES)

X X

Safe Drinking Water Act 

(Underground Injection 

Control Regulations)

X X

Clean Air Act X

Resource Conservation and 

Recovery Act (RCRA)

X X

Toxic Substance Control Act X X

National Environmental Policy 

Act (NEPA)

X X X X X X X X X

Noise Control Act X

Geothermal Resource 

Operational Order #4

X X X X X X X X X

Occupational Safety & Health 

Act (OSHA)

X X X X X

Endangered Species Act X

Source: Lunis, B.; Breckenridge, R; and McClenahan Hietter, L. “Environmental Considerations,” Chapter 19. Lund, J. ed. et al. Geothermal Direct-Use Engineering and 

Design Guidebook. 3rd edition. Geo-Heat Center, Oregon Institute of Technology, 1998. p. 444.

7
To further isolate geothermal fluids 

from the environment, production and 

injection wells in direct-use systems are 

lined with cement and steel, fiberglass, 

or thermoplastics. The method chosen 

for disposing of the spent geothermal 

fluids depends on the quality of the 

fluids, local hydrological conditions, 

and environmental regulations. In some 

instances, these fluids, once cooled, can 

be safely discharged to surface water. 

However, if they contain levels of certain 

chemical constituents—such as boron, 

fluoride, and total dissolved solids— 

above required environmental standards, 

the direct-use systems treat them, inject 

them, or both. 

In general, the total dissolved-solids 

content increases with the temperature 

of the geothermal fluids. Therefore, the 

geothermal fluids used for direct-use 

applications typically contain less than 

those used for geothermal power, but more 

than most cold-water sources. Geothermal 

fluids used for direct-use applications 

contain between 400 to 3,000 ppm of 

total dissolved solids. Most drinkingwater standards limit the amount of total 

dissolved solids at 1,000 ppm primarily 

for taste, not health considerations.

Aquaculture and horticulture businesses, 

and other industries that use geothermal 

direct-use systems typically don’t generate 

any more solid waste than those that use 

other energy resources. Actually, a few 

geothermal aquaculture operations have 

discovered an environmentally friendly 

way to dispose of the byproducts from 

fish processing activities—alligators. 

Alligators thrive in geothermally heated 

waters in unexpected climates and areas, 

such as Idaho and Colorado. And in colder 

climates, where alligators are rarely seen, 

they can generate additional income 

as local tourist attractions.

Geothermally heated livestock 

facilities make waste management 

and collection easier for farmers and 

ranchers. The geothermal water can 

be used directly for cleaning and 

sanitizing these facilities, as well as 

drying the waste. 

Table 2. Probability and Severity of Potential Environmental Impacts from Geothermal Direct-Use Projects

Impact Probability of Occurring Severity of Consequence Duration of Impact

Air quality emissions low medium short-term

Surface water discharge medium low to medium short-term to long-term

Underground contamination low medium long-term

Land subsidence low low to medium long-term

High noise levels high medium to high short-term

Well blowouts low low to medium short-term

Conflicts with cultural and 

archeological features

low to medium medium to high short-term to long-term

Social economic problems low low short-term

Chemical or thermal 

contamination

medium medium to high short-term to long-term

Solid waste disposal medium medium to high short-term

Source: Lunis, B.; Breckenridge, R; and McClenahan Hietter, L. “Environmental Considerations,” Chapter 19. Lund, J. ed. et al. Geothermal Direct-Use Engineering and Design 

Guidebook. 3rd edition. Geo-Heat Center, Oregon Institute of Technology, 1998. p. 443.

Someday, geothermally heated greenhouses, like this one in Idaho, may be able to use the 

carbon dioxide found in geothermal fluids as a growth stimulant.

PIX 13098 Bruce Green, NREL

8 
Geothermal power production in Steamboat Springs, Nevada, doesn’t impact the natural beauty of these hot springs in the nearby area.

With direct-use applications, land 

use issues usually only arise during 

exploration and development when 

geothermal reservoirs are located in or 

near heavily urbanized areas, critical 

habitat areas, or intensive agricultural 

areas. Typically, these issues can be 

resolved through proper land use and 

environmental planning. Most directuse geothermal wells are drilled using 

conventional water-well technology and 

equipment, which have even less impact 

than even the drilling technologies 

used for geothermal power plants. And 

buildings designed for direct-use space 

heating systems may actually require less 

land because there’s no need to construct 

space for conventional heating equipment 

(e.g., boilers and gas vents).

Like geothermal power plants, injection 

can be used for direct-use applications not 

only to maintain the reservoir, but also to 

prevent land subsidence. However, few, 

if any, direct-use applications require the 

removal of enough fluid that could result 

in subsidence. Also, because direct-use 

applications withdraw and inject small 

amounts of fluid compared to geothermal 

power plants, induced seismicity really 

isn’t much of an issue either.

Conclusion 

Where geothermal resources are available, 

everyone—from power companies, 

agribusinesses, and industry, to states, 

local communities, and individuals—can 

benefit environmentally from using 

geothermal energy. Because geothermal 

energy is an inherently clean form of 

energy (with no combustion), it’s easier 

to meet environmental standards and 

regulations when used. This makes using 

geothermal energy—whether for electricity 

or heat—an attractive alternative to some 

other forms of energy. And many may find 

that the environmental benefits of using 

geothermal energy also extend to reaping 

economic and employment benefits for 

their communities and the nation as a 

whole.

These alligators at a high-altitude, 8,200' 

fish farm in Colorado thrive in geothermally 

heated waters and on byproducts from fish 

processing activities, reducing solid waste 

disposal. 

PIX 07215 Sierra Pacific

PIX 05871 Warren Gretz, NREL

9
Economic Impacts and 

Employment Benefits

Economic development and employment benefits are interrelated. 

When geothermal power plants are 

planned and built, expenditures are made 

for services and equipment, as well as for 

taxes and royalties. These expenditures 

stimulate the creation of additional 

indirect jobs, more economic activity, and 

increased tax revenues. Ultimately, this 

reduces the burden on individual taxpayers 

in the community. 

The geothermal power industry provides a 

wide range of employment opportunities 

(see Job Types and Industry Profiles on 

page 13)—from exploration and drilling 

jobs; to high-tech manufacturing of 

generator, turbine, and power conditioning 

components; to maintenance jobs at 

geothermal power plants. Through the 

economic multiplier effect (see The 

Multiplier Effect on page 11), wages and 

salaries earned by industry employees 

generate additional income and jobs in 

the local and regional economy.

Geothermal energy production in the 

United States is a $1.5-billion-dollarper-year industry. In 1996, the U.S. 

geothermal energy industry as a whole 

provided approximately 12,300 direct and 

an additional 27,700 indirect jobs. The 

domestic electric generation part of the 

industry employed about 10,000 people 

to install and operate geothermal power 

plants in the United States and abroad, 

including power plant construction and 

related activities such as exploration and 

drilling. This same industry indirectly 

employed about 20,000.

Economic Impacts

One of the most important economic 

aspects of geothermal energy is that it is 

generated using indigenous resources, 

which reduces our nation’s dependence on 

imported energy, thereby reducing trade 

deficits. Reducing trade deficits keeps 

wealth at home and promotes healthier 

economies. Nearly half of the U.S. annual 

trade deficit would be erased if imported 

oil were displaced with domestic energy 

resources. In addition, there is a huge 

international market for geothermal 

energy-related equipment manufactured 

domestically, with the potential to 

Workers install new piping at one of the geothermal power plants at The Geysers in northern 

California.

decrease the trade deficit further and 

contribute to domestic economic health. 

During the next 20 years, foreign countries 

are expected to spend $25 to $40 billion 

constructing geothermal power plants.

Numerous states throughout the United 

States are now seeking to expand their 

use of geothermal energy and to realize 

the various benefits, such as energy 

supply diversity, expansion, reliability, 

environmental attractiveness, and 

economic development. Some states have 

been quick to recognize that, in many 

instances, money spent on energy leaves 

the community, going to outside utilities 

or energy suppliers. That same money 

is no longer available to foster local 

economic activity. 

Nevada’s geothermal plants produce about 

240 MW of electricity, which saves energy 

imports equivalent to about 800,000 

tons of coal or 3 million barrels of oil 

each year. In addition, state governments 

receive tax revenue. In 1993, Nevada’s 

geothermal power plants paid $800,000 

in county taxes and $1.7 million in 

property taxes. The U.S. Bureau of Land 

Management collects nearly $20 million 

each year in rent and royalties from 

geothermal plants producing power on 

federal lands in Nevada—half of these 

revenues are returned to the state. 

Economic Impact of 

Geothermal Greenhousing

Noteworthy economic growth in New 

Mexico has occurred during the last 10 

years as a result of the geothermal energy 

program at the Southwest Technology 

Development Institute at New Mexico 

State University (NMSU). New Mexico 

has taken the nation’s lead in geothermally 

heated acreage of greenhouses with more 

than half of the state’s acreage now heated 

with geothermal energy. 

New Mexico appeals to the greenhouse 

industry for several reasons, including 

a good climate, inexpensive land, a 

trained agricultural labor force, and the 

availability of relatively inexpensive 

geothermal heat. Clients of the NMSU 

incubator greenhouse have built about 28 

acres of greenhouses, which have created 

about 250 jobs with an estimated payroll 

of $3.7 million per year and estimated 

sales of $13.4 million. The largest 

geothermal greenhouse in the nation is 

the Burgett Geothermal Greenhouse near 

Animas in southwestern New Mexico. 

This 32-acre facility produces high-quality 

cut roses that are widely marketed. 

PIX 01125 David Parsons, NREL

10 
The Multiplier Effect: 

A Little Goes a Long Way

The multiplier effect is sometimes 

called the ripple effect, because a 

single expenditure in an economy 

can have repercussions throughout 

the entire economy, much like ripples 

spreading across a pond. The multiplier 

is a measure of how much additional 

economic activity is generated from an 

initial expenditure.

For example, a dollar spent on 

consumer goods in a local store might 

generate $2.00 of economic activity in 

the local economy. This occurs as the 

dollar is re-spent; the store pays its 

employees, who purchase more goods, 

all with the same original dollar.

In cases such as the purchase of 

foreign petroleum products, the 

multiplier effect shifts away from our 

domestic economy, and the benefits 

are realized elsewhere. Use of 

domestic energy resources such as 

geothermal will retain the economic 

benefit of the multiplier effect here at 

home.

The multiplier effect causes different 

types of economic benefits as a result 

of investments in geothermal energy 

technologies:

Direct effects – These are onsite jobs and income created as the 

result of the initial investment; the 

people who perform site drilling, or 

assemble generators and turbines at a 

manufacturing plant, for example.

Indirect effects – These are 

additional jobs and economic activity 

involved in supplying goods and 

services related to the primary activity; 

for example, workers who manufacture 

drilling bits and related supplies.

Induced effects – This is 

employment and other economic 

activity generated by the re-spending 

of wages earned by those directly 

and indirectly employed in the 

industry; jobs created by drilling bit 

manufacturing-plant workers spending 

their wages at the local grocery store, 

for example.

New Mexico has a total of 50 acres 

of greenhouses that are heated with 

geothermal energy. This represents a 

payroll of more than $5.6 million and 

sales of $20.6 million. Nearly all of the 

greenhouse sales are made to out-of-state 

buyers. In addition, the greenhouses pay 

royalties for geothermal production.

Altogether, the projected near-term new 

greenhouse acreage and business start-ups 

represent a capital investment of more 

than $21.5 million with sales of nearly 

$26.1 million. Nearly 500 new jobs are 

the result. Annual energy savings to the 

greenhouse operators using geothermal 

energy approaches $1 million. With 

continued growth, other suppliers and 

market brokers may move their operations 

and warehouses to New Mexico, adding to 

the revenue stream of the state economy. 

Almost all growth will occur in rural areas 

where economic development initiatives 

are frequently overlooked.

Case Study – Fourmile Hill and 

Telephone Flat Economic Impacts

Calpine Corporation has proposed 

building two new geothermal power plants 

in Siskiyou County located in northern 

California. In June 2002, Professor David 

E. Gallo of the Center for Economic 

The Masson Radium Springs Farm geothermal greenhouses are located on private land in 

southern New Mexico.

Development, California State University 

(Chico), prepared an economic impact 

analysis of these geothermal development 

projects. The study concludes that the 

total impact on real (inflation adjusted) 

business revenue in Siskiyou, Modoc, 

and Shasta counties in California and 

Klamath County in Oregon is an increase 

of almost $114 million over the projected 

30-year life span of the project. On an 

annual basis, local income will increase 

by $3.8 million annually as a result of 

construction and operation of the new 

energy infrastructure.

Dr. Gallo assessed revenue impacts in two 

stages. The local revenues (first stage) 

directly generated by geothermal energy 

development were allocated to Siskiyou 

County. This part of the analysis includes 

the county share of federal royalties and 

property taxes paid to the county general 

fund on the value of the plant.

In addition, indirect business taxes (second 

stage) accrue as a result of the increased 

regional spending. Those taxes include 

property taxes, sales tax revenues, motor 

vehicle in-lieu fees, and other state and 

federal taxes (including income, social 

security, and profit taxes) that, in part, 

are returned to the counties. 

PIX 113011 Robb Williamson

11
These tax revenues accrue to the county 

in which the initial spending occurs, and 

are allocated to the broader four-county 

regional economy. All of these economic 

facets of geothermal development 

continue to ripple through the local and 

regional economy.

As outlined in the report, “Under the two 

power plant scenario, Siskiyou County 

alone will gain more than $1 million 

annually in property tax and royalty 

revenues,” said Gallo. “These projects 

could serve as a considerable 

economic stimulus, particularly 

for a region with nearly 

double the national average 

unemployment.”

Impacts – When both power 

plants are considered, the 

total impact on real income 

in the four-county region is 

a $113,925,512 gain, and 

the yearly average gain is 

$3,797,517. Local government 

revenues for the four-county 

region increase to a total of 

$3,030,276 for a 30-year period 

(assumed plant lifetime). 

Employment Benefits

A 1994 analysis estimates 

a multiplier effect (see The 

Multiplier Effect on page 11) 

of 2.5 for U.S. geothermal 

investment; that is, one dollar 

of investment in a geothermal 

venture produces $2.50 in 

economic activity through 

spending in supplier industries 

and other effects. Assuming 

7,000 MW of U.S. geothermal 

electric capacity in 2020, this 

same analysis calculates $14 

billion in economic activity due to direct 

investment in geothermal development, 

plus another $20 billion in indirect 

activity. The total $34 billion in economic 

activity translates to 680,000 personyears of employment from 1994 to 2020 

(based on an annual salary plus overhead 

of $50,000 in 1994 dollars) for these jobs. 

In addition, operating and maintaining 

(O&M) the 7,000 MW of capacity over 

each plant’s 30-year lifetime will generate 

$525 million in economic activity. This 

equals 10,500 jobs associated with the 

plants themselves —plus 15,500 jobs 

associated with O&M equipment and 

services—for a total 765,000 person-years 

of O&M employment over the 30-year 

period.

Table 3 provides estimates of job creation 

from geothermal power development 

based on existing and planned projects 

in California, and the market outlook 

of project developers and equipment 

manufacturers. Natural gas is included 

in Table 3 because the bulk of new 

nonrenewable generation is expected to 

rely upon natural gas. Table 3 indicates 

that geothermal power generation yields 

significantly more jobs per MW of 

installed capacity than do natural gas 

plants.

Another economic impact analysis of 

geothermal power plant construction 

showed job creation of 26 jobs per 

MW of power plant capacity. A 50-

MW geothermal power plant would 

create about 1,300 jobs, based on this 

analysis. In other words, for every MW 

of geothermal power plant construction, 

26 direct, indirect, and induced jobs are 

created. This compares with between 6 

to 8 jobs created in the construction of a 

natural gas power plant (i.e., combustion 

turbine and combined cycle). O&M jobs 

—more desirable because they represent 

full-time jobs for the duration of plant 

service—were about 1.88 jobs per MW 

of geothermal plant capacity. Natural gas 

power plants showed figures of 0.21 to 

0.45 per MW for O&M jobs.

California Job Growth from 

Geothermal Development

California’s new Renewables Portfolio 

Standard (RPS) is expected to create very 

substantial growth in economic activity 

and job creation within the geothermal 

industry. The RPS is presently set at 20 

percent renewables by 2017. If California 

energy companies satisfy 50 percent of 

RPS-required renewable energy growth 

with geothermal energy, they will develop 

1,680 MW of geothermal power capacity 

over the next 14 years. 

According to the Geothermal Energy 

Association, California has the potential 

to boost output from existing plants in 

the near term by 300 to 600 MW, and 

Table 3. Comparative Job Creation

Power Source Construction 

Employment 

(jobs/MW)

O&M Employment 

(jobs/MW)

Total Employment for 500 

MW Capacity 

(person-years)

Geothermal 4.0 1.7 27,050

Natural Gas 1.0 0.1 2,460

Source: Renewable Energy and Jobs – Employment Impacts of Developing Markets for Renewables in California, 

and based on California Renewable Technology Market and Benefits Assessment, Electric Power Research Institute, 

November 2001.

Workers process commercially raised roses at a 

geothermally heated greenhouse nursery in New Mexico.

Workers assemble new growing beds for a geothermally 

heated greenhouse nursery in Utah.

PIX 13023 Robb Williamson PIX 03703 Geo-Heat Center, OIT

12 
Workers set up a coring rig at The Geysers in 

Northern California.

can develop up to 1,000 MW at known 

but undeveloped reserves at each of 

three locations—the Salton Sea, northern 

California, and The Geysers area north of 

San Francisco—for a total of 3,600 MW 

that can be practically developed with 

today’s technology.

The Geothermal Resources Council lists 

20 California-based geothermal energy 

development and service companies. 

Three of the world’s biggest geothermal 

power companies are located in California. 

These businesses should benefit from this 

growth also. Assuming that just 30 percent 

of manufacturing activity associated with 

California geothermal energy development 

occurs in-state, full realization of the 

targets in the California RPS would result 

in the employment presented in Table 4.

Conclusion

Development and use of a domestic 

energy resource such as geothermal energy 

brings with it a multitude of economic and 

employment benefits. These economic 

benefits, such as the multiplier effect, are 

greatly extended within the local domestic 

economy when development of a domestic 

energy resource is realized. Many of the 

jobs created occur in rural areas where 

economic development initiatives are 

frequently overlooked. Growth in the 

energy production sector of the economy 

will occur, and the character of the energy 

resources developed will have significant 

economic and employment repercussions 

for the United States. In turn, this growth 

will have a positive impact on the 

environment.

Table 4. California RPS-Induced 

Geothermal Employment

Construction 

Employment for 

International Market

800 person/

years

Construction 

Employment for 

In-State Market

1,230 person/

years

Operating 

Employment for InState Market

59,030 person/

years

TOTAL 61,060 person/

years

Source: Renewable Energy and Jobs – Employment 

Impacts of Developing Markets for Renewables in 

California, and based on California Renewable Technology 

Market and Benefits Assessment, Electric Power 

Research Institute, November 2001.

Job Types and 

Industry Profiles 

When the discussion turns to job 

creation, elected officials, political 

leaders, decision-makers and 

policymakers tend to listen. The 

type of jobs created can also be an 

important consideration. Here’s a 

sampling of specific jobs related 

to geothermal development: 

welders; mechanics; pipefitters; 

plumbers; machinists; electricians; 

carpenters; construction and 

drilling equipment operators and 

excavators; surveyors, architects 

and designers; geologists and 

hydrologists; electrical, mechanical, 

and structural engineers; HVAC 

technicians; food processing 

specialists; aquaculture and 

horticulture specialists; resort 

managers; and spa developers.

Economic activity and job creation within the geothermal industry impact the 

following areas:

• Mechanical equipment and primary metal suppliers make casings for geothermal 

well shafts, drilling equipment, power plant equipment and controls, pumps, and 

transport or light-construction equipment (e.g., loaders, tractors, and trucks). 

• General consultants and contractors search for geothermal resources and prepare 

simulations of resource availability and economic analysis so that developers can 

obtain financing. 

• Drilling and well services firms use resource management, geoscience, and 

stabilization technology and expertise similar to that of the petroleum industry. 

• Environmental services firms manage paperwork, permitting, well testing, water 

testing, air sampling and other tasks required for regulatory approvals. 

• Geothermal developers—under contract to a utility, government, or other entity to 

develop a project—often act as general contractors and hire other firms to do the 

work. This can include all facets of development, from construction site security and 

safety, to turnkey requirements.

• Power plant ownership and operations firms may be electric utilities or independent 

power producers, which require trained and certified power plant operators and 

maintenance staff. 

PIX 04133 Jeff Hulen

13
References

Environmental Benefits and Impacts 

of Geothermal Energy

Bloomfield, K.; Moore, J.; Neilson, Jr., R. 

“Geothermal Energy Reduces Greenhouse 

Gases,” Geothermal Resource Council 

Bulletin, March/April 2003, p. 77-79.

Duffield, W.A.; Sass, J.H. Geothermal 

Energy—Clean Power From the Earth’s 

Heat. U.S. Geologic Survey, 2003. 

Dunstall, M.G.; Graeber, G. “Geothermal 

Carbon Dioxide for Use in Greenhouses,” 

Geo-Heat Bulletin, Vol. 18, p. 1-14.

“Environmental and Economic Impacts of 

Geothermal Energy,” U.S. Department of 

Energy Geothermal Energy Program Web 

site, www.eere.energy.gov/geothermal/

geoimpacts.html (10 March 2004). 

“Environmental Impacts of Geothermal 

Energy,” U.S. Department of Energy 

Geothermal Technologies Program Web 

site, www.eere.energy.gov/geothermal/

environ_impacts.html (26 May 2004).

Geothermal: Clean Energy from the Earth. 

U.S. Department of Energy, October 1999. 

Geothermal Direct-Use Engineering and 

Design Guidebook. 3rd edition. Lund, 

J.W., ed. et al. Geo-Heat Center, Oregon 

Institute of Technology, 1998.

Geothermal Energy: Clean Sustainable 

Energy for the Benefit of Humanity and 

the Environment, University of Utah, 

April 2001.

Geothermal Today: 1999 Geothermal 

Energy Program Highlights. U.S. 

Department of Energy, May 2000.

Geothermal Today: 2003 Geothermal 

Technologies Program Highlights. U.S. 

Department of Energy, September 2003. 

“Mammoth Pacific’s Award Winning 

Facilities.” Mammoth Pacific Web 

site, www.mammothpacific.com/

awardfacilities.html (20 April 2004).

Rafferty, K.D. “Environmental 

Considerations for Geothermal Energy as 

a Source for District Heating,” ASHRAE 

Transactions, Vol. 102, Part 2, 1996, pp. 

457-460.

Reed, M.J.; Renner, J.L. “Environmental 

Compatibility of Geothermal Energy,” 

Chapter 2. Sterret, F.S. ed. Alternative 

Fuels and the Environment. Boca Raton: 

CRC Press, 1995. 

“Slimhole Geothermal Drilling.” Sandia 

National Laboratories Web site, 

www.sandia.gov/geothermal/Programs/

slimhole.htm (14 April 2004).

Economic Impacts and Employment 

Benefits

Clean Power for 21st Century, Dollars 

from Sense: The Economic Benefits of 

Renewable Energy. U.S. Department of 

Energy Office of Power Technologies, 

1997 (www.nrel.gov/docs/legosti/fy97/

20505.pdf).

The Economic Impact of Calpine’s 

Geothermal Development Projects in 

Siskiyou County, California. Center for 

Economic Development, California State 

University, June 2002 (www.csuchico.edu/

cedp/pdf/esp.calpine.pdf)

“Economic Impact of Geothermal 

Greenhousing,” New Mexico State 

University, Southwest Technology 

Development Institute Web site, 

www.nmsu.edu/~tdi/Geothermal-Energy/

EconomicImpact/EconomicImpact.html

(August 2001).

Meidav,T.; Pigott, J. “The Impact of 

Geothermal Energy Development on 

Employment,” Geothermal Resource 

Council, Transactions 18, October 1994, 

pp. 55-60.

Roberts, P; et al. DynCorp, Inc. 

“An Assessment of the Economic 

and Employment Impacts of the 

Commercialization of Renewable 

Technologies in Washington/Oregon,” 

Second Biomass Conference of the 

Americas, Proceedings, August 21 – 24, 

1995, pp. 1484-1493.

Renewable Energy and Jobs 

– Employment Impacts of Developing 

Markets for Renewables in California. 

Environment California Research and 

Policy Center, July 2003 (www.environm

entcalifornia.org/reports/renewables_jobs_

7_03.pdf).

14 
KEY CONTACTS

U.S. Department of Energy (DOE)

Roy Mink, Director

Office of Geothermal Technologies

1000 Independence Avenue, SW

Washington, DC 20585

202.586.5348

www.eere.energy.gov/geothermal

DOE Golden Field Office

Jay Nathwani, Senior Geothermal Projects Manager

1617 Cole Blvd.

Golden, CO 80401-3393

303.275.4756

jay.nathwani@go.doe.gov

www.go.doe.gov

National Renewable Energy Laboratory

Gerry Nix, Manager

303.384.7566

gerald_nix@nrel.gov

Bruce Green, Communications Contact

303.275.3621

bruce_green@nrel.gov

Geothermal Program

1617 Cole Boulevard

Golden, CO 80401-3393

www.nrel.gov/geothermal

Idaho National Engineering and

Environmental Laboratory

Joel Renner, Manager

Geothermal Program

2525 Fremont Ave.

Idaho Falls, ID 83415-3830

208.526.9824

rennerjl@inel.gov

geothermal.id.doe.gov

Sandia National Laboratories

Craig Tyner, Manager

Geothermal Research Department

P.O. Box 5800

Albuquerque, NM 87185-0708

505.844.3340

cetyner@sandia.gov

www.sandia.gov/geothermal

Program and Industry Collaboration

The Department of Energy’s Geothermal Technologies Program works in partnership 

with industry to establish geothermal energy as an economically competitive 

contributor to the U.S. energy supply. This well-established partnership helps attain 

R&D relevance and smooth adoption of new geothermal technologies. Without this 

collaboration with our many industry partners and professionals, attaining Program 

goals and objectives would be greatly impeded.

Dr. Roy Mink

DOE Geothermal Technologies 

Program Manager

15
16

Produced for the

1000 Independence Avenue, SW, Washington, DC 20585

By the National Renewable Energy Laboratory,

a DOE National laboratory

DOE/GO-102004-1985

Printed with renewable-source ink on paper containing at least 

50% wastepaper, including 20% postconsumer waste

A Strong Energy Portfolio for a Strong America 

Energy efficiency and clean, renewable energy will mean 

a stronger economy, a cleaner environment, and greater 

energy independence for America. Working with a wide array 

of state, community, industry, and university partners, the 

U.S. Department of Energy’s Office of Energy Efficiency and 

Renewable Energy invests in a diverse portfolio of energy 

technologies. 

Revised November 2004