In this essay we will be discussing the components of what Geothermal Energy is and its functions. We'll discuss part by part everything that may be Geothermal Energy. First thing you might ask... What is Geothermal Energy Exactly? Is it really that renewable? Will it have negative effects as much as of how many positive effects it has? Don't worry we'll get there right now...
Well, Geothermal Energy is energy that comes from the heat that is found beneath the earth's surface. This Energy ranges from 2000 to 5000 degrees, from almost the beginning of the earth's surface to the close center of the earth's inner crust. Let me tell you, that is hot yes! There is a layer of hot and molten rock, called magma. Heat is continually produced in this layer, mostly from the decay of naturally radioactive materials such as uranium and potassium. The amount of heat within 10,000 meters (about 33,000 feet) of Earth's surface contains 50,000 times more energy than all the oil and natural gas resources in the world. Heat from the earth can be used as an energy source in many ways, from large and complex power stations to small and relatively simple pumping systems.
The energy that is received from this reliable source is very clean by the way. So yeah it's best to say that this one is a renewable resource that is providing energy in the U.S. and also around the world in a variety of applications and resources. Although areas with telltale signs like hot springs are more obvious and are often the first places geothermal resources are used, because its obvious...heat, but no, the heat of the earth is available everywhere. It can be found as far away as remote deep wells in Indonesia and as close as the dirt in our backyards. By all this exaggerated information I mean that its actually everywhere from where we could use of its resource. Many regions of the world are already actually tapping geothermal energy as an affordable and sustainable solution to reducing the dependence on fossil fuels, and the global warming and public health risks that result from their use. Which is really good right?
A geothermal system requires heat, permeability, and water. The heat from the Earth's core continuously flows outward. Sometimes the heat, as magma, reaches the surface as lava, but it usually remains below the Earth's crust, heating nearby rock and water — sometimes to levels as hot as 700°F. Currently, the most common way of how we are capturing energy from geothermal sources is to tap into naturally occurring "hydrothermal convection" systems, where cooler water seeps into Earth's crust, is heated up, and then rises to the surface. Then once this heated water is forced to the surface, it is just a relatively simple matter to capture that steam rising and use it to drive electric generators. Just as simple as that, power will arrive to numbers of houses. Geothermal power plants drill their own holes into the rock to more effectively capture the steam.
The areas with the highest underground temperatures are in regions with active young volcanoes. These "hot spots" occur at tectonic plate boundaries or at places where the crust is thin enough to let the heat through. The Ring of Fire for its many volcanoes, has many hot spots, including some in Alaska, California, and Oregon. One state that has hundreds of hot spots, covering much of the northern part of itself is Nevada.
We are at the moment learning to use it in a much broader diversity of circumstances. The following reason for why Geothermal Energy is considered a renewable energy is because this energy resource (the heat) emanates from underneath us. This heat emanating from the interior of the Earth is essentially limitless. Now you see, and think "wow, this energy resource is unlimited” Now, you might want to hear out something amazing that I'm about to tell you and it's a fact... the heat that continuously flows from the Earth's interior, which travels primarily by conduction, is estimated to be equivalent to 42 million megawatts of power!
And as of 2013 more than 11,700 megawatts of large, utility-scale geothermal capacity was in operation globally, with another 11,700 MW in planned capacity additions on the way. What's really interesting is that these geothermal facilities produced approximately 68 billion kilowatt-hours of electricity, and man, that's enough to meet the annual needs of more than 6 million typical U.S. households.
Geothermal Energy is one energy resource that is being utilized efficiently in the U.S. with more than 3,300 megawatts in eight states, the United States is a global leader in installed geothermal capacity. An eighty percent of this capacity is located in California, where more than 40 geothermal plants provide nearly 7 percent of the state's electricity. In thousands of homes and buildings across the United States, geothermal heat pumps also use the steady temperatures just underground to heat and cool buildings, cleanly and inexpensively. Enough to say that this Geothermal energy could be the future energy resource for the use of everyone's convenience and along with Solar Panel.
Not only do geothermal resources in the United States offer great potential, they can also provide continuous baseload electricity. According to NREL (National Renewable Energy Laboratory), the capacity factors of geothermal plants which is a measure of the ratio of the actual electricity generated over time compared to what would be produced if the plant was running nonstop for that period are comparable with those of coal and nuclear power. Still, don't get that cocky, well that's if our species lives up to a billion years because actually this energy resource is expected to remain so for billions of years to come, ensuring an inexhaustible supply of energy. One thing you need to know is that there are four commercial types of geothermal power plants: flash power plants, dry steam power plants, binary power plants, and flash/binary combined power plants. Flash Power Plant: Geothermally heated water under pressure is separated in a surface vessel that is called a vessel separator, this one goes into steam and hot water called "brine. The steam is then delivered to the turbine, and the turbine powers a generator. The liquid is from there injected back into the reservoir.
Dry Steam Power Plant: Steam is produced directly from the geothermal reservoir to run the turbines that power the generator, and no separation is necessary because wells only produce steam. The steam goes up into the turbine and travels to the generator to generate electricity. Binary Power Plant: Recent advances in geothermal technology have made possible the economic production of electricity from geothermal resources lower than 302°F. This is known as binary geothermal plants. The facilities that make this posssible reduce geothermal energy's already low emission rate to zero. Binary plants typically use an Organic Rankine Cycle system. The geothermal water/fluid heats another liquid, such as isobutane or other organic fluids such as pentafluoropropane, which boils at a lower temperature than water. The two liquids are kept completely separate through the use of a heat exchanger, which transfers the heat energy from the geothermal water to the working fluid. The secondary fluid expands into a gaseous vapor. The force of the expanding vapor, like steam, turns the turbines that power the generators, and then all of the produced geothermal water is injected back into the reservoir. Flash/Binary Combined Cycle: This type of plant uses a combination of flash and binary technology that is used effectively to take advantage of the benefits of both technologies. In this type of plant, the portion of the geothermal water which "flashes" to steam under reduced pressure is first converted to electricity with a backpressure steam turbine and the low-pressure steam exiting the backpressure turbine is condensed in a binary system.
The choice of which design to use is determined by the resource. If the water comes out of the well as steam, it can be used directly, where a dry steam power plant can be used. If it is hot water of a high enough temperature, a flash system can be used. Otherwise it must go through a heat exchanger. Since there are more hot water resources than pure steam or high-temperature water sources, there is more growth potential in the binary cycle, heat exchanger design.
The largest geothermal system now in operation is a steam-driven plant in an area called the Geysers, north of San Francisco, California. Despite the name, there are actually no geysers there, and the heat that is used for energy is all steam. This area was known for its hot springs and the first well for power production was not drilled until 1924. Deeper wells were drilled in the 1950s, but real development didn't occur until the 1970s and 1980s. The Geysers facilities today still meet nearly 60 percent of the average electrical demand for California's North Coast region.
The good but bad thing is that the plants at the Geysers use an evaporative water-cooling process that creates a vacuum that is pulling the steam through the turbine, producing power more efficiently. But this process loses 60 to 80 percent of the steam to the air, without re-injecting it back underground. Still, while the steam pressure may be declining, the rocks underground are still hot. One way they tried to remedy the situation, was to have various stakeholders partnered to create the Santa Rosa Geysers Recharge Project, which involved transporting 11 million gallons per day of treated wastewater from neighboring communities through a 40-mile pipeline and injecting it into the ground to provide more steam.
The bad news is that with open systems like the Geysers is that they emit some air pollutants. Hydrogen sulfide—a toxic gas with a highly recognizable "rotten egg" odor and along with trace amounts of arsenic and minerals, is released in the steam. As an effect salt can also pose an environmental problem.
But then there's a power plant located at the Salton Sea reservoir in Southern California, where a significant amount of salt builds up in the pipes, which then must be removed. While the plant initially put the salts into a landfill, they now re-inject the salt back into a different well. With closed-loop systems, such as the binary cycle system, there are no emissions and everything brought to the surface is returned underground.
Geothermal springs are a direct use of geothermal heat. It can also be used directly for heating purposes. Geothermal hot water is used to heat buildings, raise plants in greenhouses, dry out fish and crops, de-ice roads, improve oil recovery, aid in industrial processes like pasteurizing milk, and heat spas and water at fish farms. In Iceland, virtually every building in the country there, is heated with hot spring water. Iceland gets more than 50 percent of its primary energy from geothermal sources. Geothermal energy has the potential to play a significant role in moving the United States and other regions of the world toward a cleaner, more sustainable energy system. It is one of the few renewable energy technologies that can supply continuous, baseload power. Not unlike coal and nuclear plants, binary geothermal plants can be used a flexible source of energy to balance the variable supply of renewable resources such as wind and solar.
In order for us to tap into the full potential of geothermal energy, there's two emerging technologies that require further development which are: Enhanced Geothermal Systems (EGS) and co production of geothermal electricity in oil and gas wells.
An approach to capturing the heat in dry areas is known as enhanced geothermal systems (EGS) or "hot dry rock". One cause for careful consideration with EGS is the possibility of induced seismic activity that might occur from hot dry rock drilling and development. This risk is similar to that associated with hydraulic fracturing.
Low-temperature geothermal energy is derived from geothermal fluid found in the ground at temperatures of 300°F or less. These resources are typically utilized in direct-use applications, such as heating buildings, but can also be used to produce electricity through binary cycle geothermal processes. In the meantime during the better development of EGS and co-production of geothermal electricity in oil and gas wells, I believe Geothermal Energy could be the best renewable energy resource so far.