World Bank Energy DaysRE Technology Session

Geothermal Power

Karl Gawell, GEA

February 23, 2012

How does a geothermal power plant work: Main features, characteristics of a binary power plant

While flash steam plants continue to be built, there is a growing trend toward binary power systems as shown below. Nearly all new geothermal power plants in the US have been binary systems using the heat of the earth through a working fluid to produce zero emission power on a continuous basis (as shown in the diagram). Most also utilize air cooling. Picture is Ormat’s Burdette Power Plant in Reno, NV.

Power Characteristics• Utility-scale geothermal power

production adds reliability to the power system. Geothermal power can be produced as a baseload renewable energy resource, meaning it operates 24 hours a day, 7 days a week regardless of changing weather, providing a uniquely reliable and continuous source of clean energy. As a baseload power source, geothermal is well suited as a substitute for coal in our utility system.

• Or, geothermal power can be flexible to support the needs of intermittent renewable energy resources such as wind and solar. Because geothermal energy can also be ramped up or down depending on need it can be used to supplement the integrity of the power grid, enhancing the efficiency of the entire system while providing clean, reliable power.

• Geothermal is also capable of achieving high capacity factors – a measure of actual output over a period of time – usually at or above 90%, which is on par with, or higher than, other baseload power sources such as coal-fired or nuclear power plants, and much greater than intermittent sources.

• Geothermal power production is also scalable. Power plants as small as a few tens of kW can be economically built for applications in communities, while utility-scale facilities on the multi-MW scale are common.

Technology Maturity

• Maturity: the quality or state of being mature; esp. full development.

• Mature: having completed natural growth and development

• (Merriam-websters.com)

• While geothermal resources have been in use for thousands of years, the technology for power production is still emerging.

• Only a small fraction of the known hydrothermal resource base is being utilized, and most of the resources is estimated to be “undiscovered.”

• Key area for new technology: exploration and drilling technology to reduce risk and up-front cost. US DOE significant work in this area with $200 million in 24 cost-shared underway.

• Power systems improvements continue with projects showing higher efficiencies and ability to use lower temperature resources

Key Technology Challenge

• Exploration technology and techniques still maturing– Most geothermal resources still “undiscovered” according to USGS– Pre-drilling exploration techniques rarely provide an unambiguous

drilling target (≤50% drilling success rate)• Drilling makes up nearly half of project costs• Successful drilling results are needed to secure financing

– Exploration technologies adapted from oil and gas sectors do not yield the same rates of success in geothermal exploration

• Increased research needed in geothermal exploration technologies – Geothermal exploration and drilling have high risk profiles

• THEN: Exploration and drilling by large resource companies who understand natural resources , have suitable risk thresholds and deep pockets

• NOW: Geothermal industry is dominated by smaller companies with limited access to capital and lower risk thresholds

Other challenges

• Geothermal project lead-times can take 4-8 years, or more, before a plant is brought online and projects face obstacles at key points throughout development

• In US, competition with other renewables in markets being “glutted” with power project proposals, and often having short-term procurement horizons

• California utility solicitations in 2011 received “Over 1,000 unique bids and 3,000 proposals from over 260 sellers were submitted, representing approximately 91,000 MW of proposed renewable capacity.”

• “IOUs shortlisted over 30 proposals consisting of biomass, geothermal, small hydro, wind, and solar PV, representing approximately 3% of renewable generation that was bid into the 2011 RPS Solicitation” (CPUC 4Q RPS 2011 Status Report)

Costs• Costs will vary depending upon choice of

technology, project lead time, resource temperature and flow rate, transmission requirements, whether the project is an addition to a know resource of “greenfield” development, and other factors. Costs should improve as more is known about a particular geologic area and resource, and as technology improves. Cost estimates vary widely, here are two:

California Energy Commission Comparison of Levelized Costs 2009

US DOE 2011 Cost Estimate – New Undiscovered Hydrothermal Site

World Market

• IGA reports 2011 Geothermal CAPACITY on-line at 10,716 MW

• Bloomberg New Energy Finance Forecast 4GW of capacity additions on-line worldwide by 2020, with roughly 10 additional GW in the pipeline (GEA Finance Forum, Jan 2012)

• Pike Research notes that in addition to 26 countries now utilizing geothermal resources for energy, additionally over 50 countries in six continents have exploration underway (GEA Finance Forum, Jan 2012)

Total Global Installed Geothermal Capacity: ~ 11 GW

Capacity Addition by Technology, 2008-Present

Capacity Addition by Country, 2008-Present

2005 2006 2007 2008 2009 20100

50

100

150

200

250

300

350

400

450

500

280

241

316

464

401

242

Binary Flash

Dry Steam Back Pressure

391

373

338

334

140

73

73

5350

4924 46

United States

Iceland

Indonesia

New Zealand

Italy

Turkey

Kenya

El Salvador

Papua New Guinea

Philippines

Guatemala

Other

~1944 MW of Geothermal Capacity Installed from 2005 through 2010

Year

El Salvador Iceland Indonesia Italy Japan Kenya MexicoNew

ZealandPhilippines

United

States

199095 45 145 545 215 45 700 283 891 2,775

1995105 50 310 632 414 45 753 286 1,227 2,817

2000161 170 590 785 547 45 755 437 1,909 2,228

2005151 202 797 791 535 129 953 435 1,930 2,564

2007204 421 992 811 535 129 953 472 1,970 2,924

2010204 575 1,197 863 536 167 958 628 1,904 3,087

2015290 800 3,500 920 535 530 1,140 1,240 2,500 5,400

Geothermal power: Top 10 countries: Units: MWSource: Íslandsbanki Published: 24. 2. 2011

Scope for Improvements• Exploration technology – better technology could

reduce major risk factor and speed development lead time

• Power efficiency – better efficiency improves economics and modular systems speed development lead time

• Power systems utilizing lower temperature resources – greatly expands areas with power potential

• Small modular systems utilizing lower temperatures are spurring new distributed generation mode for geothermal in the US

Opportunities

• Geothermal power can be utility scale baseload power, flexible firming power, or distributed generation.

• Geothermal/solar hybrid offers favorable power output profile and optimizes lands use.

• Large untapped resource base offers opportunity for rapid expansion on every continent with improved technology.

Geothermal Energy is Good for the Environment

1,041

622

46 39 18 17 15 14

Coal Natural Gas Biomass Solar PV Hydro Nuclear Geothermal Wind

Geothermal has very low life-cycle carbon dioxide emissions compared to other technologies: (15 tons of Carbon Dioxide Equivalent per Gigawatt-Hour)

Geothermal has a very small footprint compared to other technologies:(Land Use 404 square meters /GWH)

Source: "Life-Cycle Assessment of Electricity Generation Systems and Applications for Climate Change Policy Analysis," Paul J. Meier, University of Wisconsin-Madison, August 2002.

For more information:www.geo-energy.org

202-454-5261