The fourth annual GEA International Geothermal Energy Showcase concluded Wednesday, May 23, in Washington DC. The conference featured countries and projects in 6 different regions of the world: Asia and the Pacific, Europe, Turkey, Latin America, the Caribbean, and East Africa. Presentations by corporate and country leaders, for many of the projects, were very similar, but a few had unique challenges. Ultimately, what started out with policy, charts, and graphs ended up with a human face and concerns in Nevis and East Africa. The showcase was well-organized, resulting in a virtually flawless program.
Keynote Speaker: Sen. Jeff Bingman
Sen Jeff Bingaman (D-NM), Chairman of the Senate Energy and Natural Resources Committee, provided the keynote address. Highlights of his speech were echoed throughout the presentations:
- The US has had occasional periods of mass investment in our energy infrastructure. The present time seems to be one of these.
- Energy security will come from diversity.
- While shale gas may present an inexpensive option, concentration only on this potential is not diverse and not secure.
- In addition to jobs and an alternative source of energy, geothermal technology is a multi-billion-dollar market for international trade.
- The US has the greatest installed base of geothermal energy in the world but the present pace of development is slowed primarily due to policy which is unlikely to change until after the November elections. “…our competitors are making a compelling case to investors and entrepreneurs that it is simply good business to develop there, rather than develop here.”
- Continuing the PTC in the fall is likely to be a bargining chip to extend the Bush tax cuts.
- The Clean Energy Standard legislation he introduced in March has been described as “plan C” by the Washington Post.
Geothermal Power Development Dates from the 60’s
The US began development of utility-scale geothermal in the 60’s and has the most installed generating capacity at 3187 MW. When referring to geothermal, a distinction is made between uses for power generation and “direct usage” (as heat energy). China uses more geothermal energy than us, but primarily for heating, and it is only beginning to use geothermal for electrical generation. In association with the conference, an International Geothermal Overview was concurrently released. Worldwide, there are approximately 11 Gigawatts installed.
With limited growth in geothermal power in the US, the focus was on exportable technology. “One of the best aspects geothermal has to offer is that it is very exportable,” remarked Halley Dickey, Director Geothermal Business Development, TAS Energy, headquartered in Houston, Tex. “We build the entire plant here in the U.S. and export it abroad.”
Different Types of “Geothermal”
The GEA website contains a tutorial that outlines the various technologies used to tap the Earth’s heat energy. As we drill deeper into the Earth’s crust anywhere, temperatures will rise. In some places, that heat is closer to the surface. If the heat is also associated with water, drilling will release steam that can be used for direct heating or in a Dry Steam Power Plant. Other locations will need to manipulate the energy to make it useable.
A Flash Power Plant separates steam from hot water. A binary power plant uses an organic Rankin cycle (like a heat pump) to use low heat energy sources. In some places, there is enough heat but no water to produce steam. Deep in the Earth the rock may be fractured and water injected. This is known as Enhanced Geothermal Systems (EGS). All of the above systems use deep wells that can be over 2 miles into the earth. These tap into the Earths natural heat. Useable temperatures may be from 150 deg F to 700 deg F.
Geothermal wells for heat pump systems are more shallow, in the range of 150 to 600 feet. These wells take advantage of the relatively constant “surface” temperatures of around 55 deg F (depending upon location) and the magic of heat pumps to heat and cool homes and businesses. The Earth’s surface temperatures would be more than 20 degrees less without the additional heating effect of the sun. To some extent, then, Geothermal heat pumps are like wind energy, an adaptation of solar radiation, but far more constant due to the thermal mass of the Earth.
Nevis and East Africa
While every project presents a unique situation, two were particularly interesting. As with many islands, Nevis must produce its electricity without the benefit of a substantial grid. Similar to many islands, that power is produced with diesel generators. At $0.37 per kWh (equiv) that power is costly and polluting. This conflicts with tourism, the island’s principal source of income that capitalizes on the island’s natural beauty and greenery.
Land and equipment is limited, but reliability is paramount for the primary electrical production plant. With a capacity factor that can reach 96%, geothermal is an excellent option. With steam venting here at 485 deg F, this is a potent resource. Peak load is about 8.5 MW with a resource potential of up to 150 MW.
East Africa has many natural resources, including geothermal energy potential. There are hydroelectric plants, but these are actually unreliable with the extended dry periods. Economics and land use are significant concerns. Geothermal collects a concentrated energy source when compared to solar or wind. The land use is therefore much less. When enough land is set aside for geothermal, as it was in Kenya 30 years ago, it can support multiple uses. As if to proclaim the cleanliness of geothermal energy, Kenya’s first geothermal power plant is now located in the middle of a nature preserve.
But East Africa also needs employment. Electrification can support higher technology and a better standard of living, but employment is addressed with direct geothermal projects that use the heat and humidity in greenhouses and fish farms.
An Issue of Pollution
Prior to the showcase, I added to the comments section in another CT article that suggested that geothermal in Hawaii was not a workable plan. At a media roundtable, I was able to ask about emissions from some geothermal power plants.
First, we have to keep in mind that geothermal is an improvement over diesel generation. On islands like Nevis and Hawaii, where there is not a large grid, baseload power may be required and geothermal fits that description. An older plant like PVG may not be as adaptable as new construction, but the technology exists to capture emissions and, in some cases, turn chemicals into marketable products for industry. In the US, geothermal plants are required to contain emissions. At the roundtable I was offered and hope to yet receive the GEA’s response to complaints like these. Look for further updates.
Into the Future
Geothermal energy can be adapted to produce electricity in a number of ways. It can also condition our environments and provide jobs. Worldwide, there is enough easily obtainable geothermal energy to satisfy all of our electrical energy demands. In choosing geothermal, we take advantage of a more concentrated type of clean alternative energy with a smaller footprint. Geothermal is an exportable technology that can also be used to generate not only electricity but jobs around the world.
US Geothermal Resource Map via Wiki Commons