1. World Bank Energy Days RE Technology Session Geothermal Power
Karl Gawell, GEA
February 23, 2012

2. 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.

3. 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.

4. 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

5. 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

6. 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)

7. 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:

8. California Energy Commission Comparison of Levelized Costs 2009

9. US DOE 2011 Cost Estimate – New Undiscovered Hydrothermal Site

10. 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)

11. Total Global Installed Geothermal Capacity: ~ 11 GW
~1944 MW of Geothermal Capacity Installed from 2005 through 2010
Capacity Addition by Technology, 2008-Present
Capacity Addition by Country, 2008-Present

12. Source: Íslandsbanki Published: 24. 2. 2011
Geothermal power: Top 10 countries: Units: MW
Source: Íslandsbanki Published:
Year
El Salvador
Iceland
Indonesia
Italy
Japan
Kenya
Mexico
New Zealand
Philippines
United States
1990 95 45
145
545
215
700
283
891
2,775
1995
105 50
310
632
414
753
286
1,227
2,817
2000
161
170
590
785
547
755
437
1,909
2,228
2005
151
202
797
791
535
129
953
435
1,930
2,564
2007
204
421
992
811
472
1,970
2,924
2010
575
1,197
863
536
167
958
628
1,904
3,087
2015
290
800
3,500
920
530
1,140
1,240
2,500
5,400

13. 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

14. 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.

15. Geothermal Energy is Good for the Environment
Geothermal has a very small footprint compared to other technologies:
(Land Use 404 square meters /GWH)
Geothermal has very low life-cycle carbon dioxide emissions compared to other technologies: (15 tons of Carbon Dioxide Equivalent per Gigawatt-Hour)
Source: "Life-Cycle Assessment of Electricity Generation Systems and Applications for Climate Change Policy Analysis," Paul J. Meier, University of Wisconsin-Madison, August 2002.

16. For more information: