Geothermal Energy Intro to Geothermal Energy Geothermal comes

Geothermal Energy

Intro to Geothermal Energy “Geothermal” comes from Greek words geo, meaning “earth, ” and therme, meaning “heat. ” Geothermal Energy is the heat produced from the Earth’s core. The core’s heat radiates to the upper mantle. The core can reach up to 9, 000°F. The mantle’s temperature can vary between 900 and 1600°F.

Different Forms of Geothermal Direct Energy Geothermal Heat Pump Geothermal Power Plant

Direct Energy Near-surface hot springs or geothermal reservoirs pump hot water to the surface. Pipes pull a hot resource up to the surface, a heat exchanger takes heat from the resource, and the unused water is injected back into the ground. For example, direct energy is used in hot spring pools like Warner Springs.

Geothermal Heat Pump Dirt underground is a constant 50°F to 60°F. Water enters the building through pipes called “loops” and is converted to heat or cool the building. Used in the Midwest and back east to heat and cool buildings.

Power Plants use underground steam to drive turbines which generate electricity.

Three types of Geothermal Power Plants: 1. Steam Plants Steam directly from a reservoir spins turbines in generators, creating electricity. 2. Flash Steam Plants 300°F to 700°F water is pumped from an underground well. The water turns into steam powers a generator. 3. Binary Cycle Plants Geothermal resource goes into a heat exchanger. The heats a second liquid, which boils and creates steam to turn turbines.

How Does Geothermal Energy Get to the Earth’s Surface? The core’s heat radiates outward into the mantle. The heat melts the mantle’s rock into magma. This magma does either of two things: 1. Reaches all the way to the surface, turning into lava flows. 2. Stays below the surface, heating rock and water around it. The mass of heated minerals and water below the surface is known as a geothermal reservoir. To create electricity, the geothermal resource must be brought to the surface so the heat can be extracted. Lava CORE HEAT MANTLE GMA MA MA GM A SURFACE Geothermal Reservoir Water and Rock

Where the energy comes from:

The superheated fluid is an important natural resource. It’s “the resource” for power. It’s “scrubbed” to get clean steam. The steam drives turbines and generates electricity.

Why use geothermal? It is a renewable energy- Clean and Green! It can be used instead of fossil fuels. Burning fossil fuels is detrimental to the earth’s ecosystem, causing global warming. Using Geothermal Energy protects the Earth’s atmosphere! Geothermal is more reliable than sun or wind.

Global Warming

How is Electricity Generated? Most commercial electrical power is based on spinning a wire coil in a magnetic field. Mechanical energy (motion) is converted into electrical energy. Most power plants use fossil fuels such as coal or gas to drive turbines to generate electricity.

From Steam to Usable Electricity

Renewable Energy Generation Geothermal plants use steam from fluid that is super-heated by magma deep under the earth’s surface. Instead of steam, windmills use wind and dams use water to drive the turbines.

Reinjection is the process of returning the geothermal fluid that was taken from the mantle back into the underground. Excess steam is condensed back into fluid and is also returned to the mantel. This is what makes the geothermal resource renewable. The geothermal fluid will be reheated in the mantle and can be used again. If a power plant decides not to use the process of reinjection, it runs the risk of diminishing the underground resource.

Reinjection Process Explained

Geothermal Energy in History 10, 000 years ago- Paleo-Indians used hot springs for cooking and bathing. 1830 - Hot Springs, Arkansas- Asa Thompson charges money for hot springs bath. First commercial usage. 1900 - Hot spring water is pumped to homes in Klamath Falls, Oregon. 1904 - First Geothermal power plant in Larderlello, Italy

History (cont. ) 1921 -Drilling at The Geysers with intention of producing electricity Unsuccessful at first A year later, successful as the first US geothermal power plant 1960 - USA’s first large scale geothermal electricity generating plant By Pacific Gas & Electric 1970 - Geothermal Resources Council is formed 1977 - US Department of Energy (DOE) is formed

Geothermal Energy and Mineral Corporation Nevada corporation founded in 1968

How Energy Gets to You! GEMCOR Gemcor owns the land containing the steam wells Cal Energy operates the power plant, converting the geothermal resource into electricity. Southern California Edison transports and sells the electricity. CAL ENERGY SOCAL EDISON

Gemcor Today and in the Future With help from Cal Energy, Gemcor’s resource produces 166 Megawatts (MW) of electricity. Two new sites at Black Rock are planned to open, which will add 200 MW of electricity to Gemcor’s production. The next slide will show a video tour of Gemcor’s first production plant.

Gemcor Plant - Outside

Gemcor Plant - Control Room

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