Environmental Science II Geothermal Energy

FOR STUDENTS & TEACHERS

1. Geothermal Energy By: Ms. Bahaw

2. Objectives Definitions Discuss if it's a renewable or non renewable/ finite and infinite resource. Operational systems Advantages and Disadvantages of its use. Emphasis on the Caribbean. Challenges encountered with extraction, transportation, political and ethical, environment, financial (Gov. Incentives) etc Reference case studies or examples where this system is used.

3. What is Geothermal Energy? Geothermal energy is the heat produced deep in the Earth's core . Geothermal energy is a clean, renewable resource that can be harnessed for use as heat and electricity. Geothermal energy is heat that is generated within the Earth. Most of the Earth’s geothermal energy does not bubble out as magma, water, or steam. It remains in the mantle, emanating outward at a slow pace and collecting as pockets of high heat. This dry geothermal heat can be accessed by drilling, and enhanced with injected water to create steam.

4. https://www.youtube.com/watch?v=c7dy0hUZ9xI

5. Is it renewable and infinite? Yes it is renewable because it cannot be used up. Because its source is the almost unlimited amount of heat generated by the Earth's core Yes is it infinite in terms of the abundancy and inexhaustible amounts of heat trapped within the Earth’s mantle. The geothermal resource is more consistent than hydro, solar and wind, as it doesn't depend on the weather , but the geothermal heat in a reservoir is finite.

6. Geothermal Power Plant

7. Harnessing of Geothermal Energy Geothermal energy may be tapped as: Dry steam - water vapour that has no water droplets Wet steam - a mixture of steam and water droplets Hot water trapped in fractured or porous rock at various places in the Earth’s crust There are three nearly non - depletable courses of geothermal energy: Molten rock or magma Hot dry-rock zones Warm-rock reservoir deposits

8. Operating System https://youtu.be/j7q653ffQO4

9. Harnessing of Geothermal Energy

10. Advantages of Geothermal Energy 1. Environmentally Friendly - the carbon footprint of a geothermal power plant is low. While there is some pollution associated with geothermal energy, this is relatively minimal when compared to fossil fuels . 2. Renewable - the hot reservoirs within the Earth are naturally replenished, making it both renewable and sustainable. 3. Huge Potential Worldwide energy consumption is currently around 15 terawatts. It is currently estimated that geothermal power plants could provide between 0.0035 and 2 terawatts of power. 4. Sustainable / Stable Geothermal provides a reliable source of energy as compared to other renewable resources such as wind and solar power. This is because the resource is always available to be tapped into, unlike with wind or solar energy.

11. Advantages Continued 5 . Reliable and high efficiency rate Energy generated from this resource is easy to calculate since it does not fluctuate in the same way as other energy sources, such as solar and wind. For every unit of electricity the system uses, it provides three to four units of heating energy - an efficiency of 300% to 400% . 6. No Fuel Required Since geothermal energy is a naturally occurring resource there is no fuel required, such as with fossil fuels that are a finite resource which needs mining or otherwise extracting from the earth. 7. Rapid Evolution There is a great deal of exploration into geothermal energy at the moment, meaning that new technologies are being created to improve the energy process. There are an increasing number of projects to improve and grow this area of industry. With this rapid evolution many of the current cons of geothermal energy will be mitigated against.

12. Disadvantages of Geothermal Energy 1. Location Restricted - i t is location specific. Geothermal plants need to be built in places where the energy is accessible, which means that some areas are not able to exploit this resource. Of course, this is not a problem if you live in a place where geothermal energy is readily accessible, such as Iceland. 2. Environmental Side Effects Although geothermal energy does not typically release greenhouse gases, there are many of these gases stored under the Earth’s surface which are released into the atmosphere during digging. 3. Earthquakes Geothermal energy also runs the risk of triggering earthquakes. This is due to alterations in the Earth’s structure as a result of digging. This problem is more prevalent with enhanced geothermal power plants, which force water into the Earth’s crust to open up fissures to greater exploitation of the resource.

13. Disadvantages Continued 4. High Costs Geothermal energy is an expensive resource to tap into, with price tags ranging from around $2-$7 million for a plant with a 1 megawatt capacity. However, where the upfront costs are high, the outlay can be recouped as part of a long-term investment. 5. Sustainability In order to maintain the sustainability of geothermal energy fluid needs to be pumped back into the underground reservoirs faster than it is depleted. This means that geothermal energy needs to be properly managed to maintain its sustainability.

14. Geothermal Energy in the C’bean Although geothermal resources are abundant on several of the islands, apart from Guadeloupe, geothermal development is still in the early stages for several reasons: Geothermal development is not a priority in the energy policies of the island governments. Traditionally, the islands have depended on diesel generation, with the exceptions of Dominica and St.Vincent which use hydroelectric power. None of the countries have geothermal laws; many do not have laws for the regulation of the electricity sector in particular. Limited financing and the high cost of geothermal exploration has held back the projects in the feasibility stage. There are no economic incentives for geothermal development. The population, and consequently the markets, of the islands are small

15. Geothermal Energy Potential 1. Guadeloupe - only territory with a geothermal energy plant in the Caribbean, which produces five per cent of the island's electricity 2. St. Lucia 3. Dominica 4. St. Vincent 5. St Kitts & Nevis 6. Grenada 7. Martinique 8. Montserrat

16. Estimated Capacity of Geothermal Energy in the C’bean