Green, Renewable Power-Geothermal Energy

April 12, 2009 by  
Filed under Geothermal Energy

Green power is any source of energy that is clean, environmentally friendly, and renewable. There are a few sources of green power in nature, and one with many uses that not many people know a lot about is geothermal energy. However, it has been used for a long time. Thousands of years ago, Native Americans harnessed geothermal energy from hot springs for medicinal use and cooking.

Geothermal energy comes from within the earth. There is ample heat energy inherent in our planet. At the Earth’s core, 4,000 miles down, temperatures can reach higher than 9,000 degrees F. One of the most plentiful resources on our planet is water. Geothermal energy is the energy used to heat water, which requires high temperatures. Wells can be drilled in geothermal reservoirs to tap hot water from the earth and bring it to the surface. Research is done by geologists to locate pockets of underground geothermal energy. When steam or hot water reaches the earth’s surface through injection wells, the energy can be used to produce electricity or heat power that won’t pollute the environment.

Even though geothermal energy is far from new, it is becoming more popular because of the trend to go green and use renewable power to reduce pollution, save money, and reduce dependence on traditional fossil fuels. Hot water used to transfer geothermal energy can be reused over and over, making it renewable and clean. There are absolutely no greenhouse gas emissions, making the energy 100% eco-friendly.

As an effective generator of electricity, geothermal power is channeled in a few different ways. At flashed-steam plants, steam from flash boiled water is used for turning turbines. Dry steam plants rely on natural steam from underground reserves to create electricity. At binary geothermal power plants, hot water is utilized to heat another liquid, which is vaporized. The process causes turbines to turn and creates electricity. Hybrid power plants use a combination of the binary and flash techniques together.

There are many other uses for geothermal energy, such as warming fishing farms, drying fruits or vegetables, drying wood or wool, heating roads and sidewalks, or getting gold and silver out of ore. However, the most popular use of the renewable source is for residential home heating through direct use district heating systems or by using a geothermal heat pump.

District heating systems have been used for decades to heat buildings. It works by piping hot water just under the earth’s surface directly into buildings for heat. Geothermal heat pumps use constant temperatures in the upper 10 feet of the Earth’s surface (50 to 60 degrees F. year round) to heat and cool buildings. Heat or coolness is simply transferred from the ground or groundwater into buildings to offset cold or hot temperatures outside. Geothermal heat pumps are quickly replacing traditional heating and cooling systems because of their efficiency, cost effectiveness, and benefits to the environment.

Geothermal energy has been used for such a long time for good reason. It continues to hold great promise for a wide variety of uses that have little or no impact on the environment. As a green power source to create electricity and heat and cool buildings, it would seem our amazing planet was created to be self sustaining.

Geothermal Energy–Earth’s Sustainable Heat Source

March 8, 2009 by  
Filed under Geothermal Energy

Did you know that below the earth’s crust is a powerful, renewable source of heat energy? Way down in the earth’s core, 4,000 miles below the crust, temperatures rise higher than the surface of the sun. Geothermal comes from two greek words: geo (earth), and therme (heat). It makes sense that geothermal energy is simply heat generated within the earth. You can see evidence of geothermal energy rising to the surface if you visit an active volcano, geyser, hot spring, or fumarole.

Harnessing this source of heat energy is as easy as drilling a well to reach hot water and steam for use in producing energy. Like any energy source, there may be advantages and disadvantages, but the use of geothermal energy dates back to antiquity. Many ancient cultures have used hot springs for bathing, cooking, or heating, such as the ancient Romans, Native Americans, and the Chinese.

Today, there are two general applications to make use of geothermal heat. The first, geothermal heat pumps, need only reach to the first 10 feet under the Earth’s crust. What’s advantageous of the temperature here is that it is consistent, rarely wavering from a range of 50 to 60 degrees Fahrenheit. During winter months, heat from underground, which is warmer, can be pumped to a building. In summer months, the same technology can be utilized to pump in cooler air. All that is required for this geothermal application is a heat pump, pipes, and duct work.

The second application involves wells to hot water or steam below the Earth’s surface. By drilling into hard rock, steam or heat is generated that can provide power. This is also a way to reach hot water near the surface that pools beneath the crust, which can be pumped to nearby buildings for heat.

The greatest benefit of geothermal energy is its environmental impact, or lack thereof. There is little or no impact, because the Earth never stops heating. This makes the energy renewable and sustainable. After water and steam from geothermal reservoirs has been used, it can be injected back into the earth for reuse.

Geothermal power plants give off relatively low emissions because no fuel is burned to generate electricity. In fact, compared to a fossil fuel plant, geothermal plants release less than 1 percent less carbon dioxide emissions and 97 percent less acid rain. Although hydrogen sulfide is found naturally in the hot water and steam, scrubber systems are utilized in geothermal plants to clean the air of this compound.

There are also a few disadvantages. One is the corrosiveness of the fluid itself. In comparison to steam boilers, the temperature reached by geothermal power is lower. This means that the power needs to be used quickly and efficiently. Also, toxic metals or chemicals such as mercury or arsenic can be found in trace quantities in geothermal water. For this reason, it can never be disposed of in natural waterways.

Despite the few disadvantages, geothermal power plants are becoming more widespread. There are 33 areas in California and 14 in Nevada utilizing geothermal energy. Direct use heating applications and power plants run by geothermal power are efficient and eco-friendly, and usage in the future may grow exponentially with no adverse impact to our planet.