Geothermal Heat Pump-Why are Geothermal Heat Pumps Efficient

Geothermal heat pumps are used for space heating and cooling, and if so equipped, also to heat water. Their high efficiencies are gaining more and more popularity for both residential and commercial buildings. It's not hard to see why. Rather than obtain heat through the combustion of fossil fuels, geothermal heat pump use the natural existing heat from the earth's ground source.

Think of the temperature of the ground as that of a cave. Beneath the earth's surface, the temperature remains relatively constant. Simply put, a geothermal heat pump takes the heat stored in the earth and transfers it into your home or office. During the summer, it does the opposite by transferring the heat from your home or office back into the ground. In other words, the ground acts as a natural heat source in the winter and a heat sink during the summer months.

But how does this highly energy efficient geothermal heat pump do this? First, a series of pipes, called a 'loop,' are buried either vertically or horizontally deep in the group. A water or anti-freeze solution circulates through the surrounding soil absorbing the earth's heat, or in the summer, relinquishing heat.

During the winter, heat is removed from the fluid in the earth's connection, concentrated, and transferred into your home. The processed is reversed in the summer; heat is removed from your home, concentrated, and placed back into the ground. Voila! An energy efficient system that reduces greenhouse gas emissions, cuts your electric bill nearly in half, requires lower maintenance, and may even lower your hot water bill.

By Geothermalcredit

Geothermal Heat Pump-Residential Heating And Cooling With Geothermal Heat Pumps

The term geothermal literally means Earth/Ground (Geo) Heat (thermal). Geothermal, or ground source heat pumps, take advantage of the constant ground or groundwater temperatures. These heat pumps use geothermal energy to heat and/or cool your home.

A refrigerant loop with a compressor extracts heat from one side (the ground) and pumps it to the heating loop in your home. It is essentially the same process that happens in your refrigerator: heat is extracted via a compressor and refrigerant loop from the inside of your refrigerator/freezer and rejected into your house.

In the summer the geothermal heat pump reverses its cycle, if you have an air-conditioning system, and heat from the home is rejected into the ground or ground water.

What makes geothermal heat pumps such a good choice for residential heating and cooling is that they do not depend on outside air temperatures. These heat pumps will heat your home as efficiently on a windy, zero-degree winter day as on a 40-degree day. Provided of course, that your house is well insulated and tight.

Geothermal heat pumps are also a very efficient way for heating and cooling your home. They use 25-50% less energy than conventional heating and cooling systems (Source: US DOE).

Residential applications of geothermal energy systems use water-to-water or water-to-air heat pumps.

Water-to-Water Geothermal Heat Pumps

Water-to-water geothermal heat pumps are generally used for heating only. They replace the gas or oil furnace that you might currently have to heat your home and water with.

It is important to know that heat pumps work most effectively when the temperature difference between the heat source (ground) and heat sink (floor heat or radiators) is small.

Ground temperatures range anywhere from 50 to 75 degF, depending on where you live. This means that geothermal heat pumps are generally not suitable for standard hot water baseboard applications, which are designed for heating water temperatures of 180 degF. Floor heat and low-temperature radiators require water temperatures in the range of 95 to 140 degF.

Some newer heat pump models are now equipped with so-called desuperheaters that can transfer excess heat from the geothermal heat pump compressor to the domestic water heater. Your geothermal heat pump can also effectively and quickly heat water for your bathtub, shower and sinks.

Water-To-Air Geothermal Heat Pumps

These types of ground source heat pumps are generally used when you need air conditioning. The Water is the heat sink, where you reject the heat from the house. The Air is the air that is distributed through your home via duct work.

Otherwise, these heat pumps function the same way as water-to-water heat pumps. And again, the efficiency of a geothermal heating and cooling system is far better than that of a traditional system.

Important To Know

The first step towards making a geothermal heat pump system be a reliable and efficient heating (and cooling) system for your home is to minimize the heating and cooling requirements with a well-insulated building envelope and strategically placed windows for passive solar gain.

Not only is your first cost reduced, because your system will be smaller. You will also tremendously increase the comfort of your home.

Geothermal heat pump systems are best designed and installed by professionals. It is not recommended to DIY. These systems must meet specific requirements. Especially the piping laid out in the ground, or down to the ground water table, must be designed and installed correctly to ensure that your geothermal heat pump system works as intended.



By Christiane Perrin

Clean Geothermal Heat From Geothermal Heat Pump-Geothermal Power Plants - Geothermal Power 101

Geothermal power involves the use of geothermal heat from below the earth's surface to generate electricity or heat. It was Giovanni Contifirst who discovered the process of generating electricity with geothermal heat in 1904 in Larderello, Italy, but geothermal energy has been used for heating and cooling as far back as early Roman times.

Heat from the earth can be used in many ways, from utility-grade power stations to simple heat pumps for residential applications. This heat energy, known as geothermal energy, is a renewable source that can be found almost anywhere worldwide.

The heat continuously flowing from the earth's interior is estimated to be the equivalent of 42 million megawatts of power (which is equivalent to the electricity that would be used by more than 30 billion homes).

Tapping geothermal energy is a clean and affordable way to generate electricity and heat and avoid the use of fossil fuels.

Under the earth's crust is a layer of hot and molten rock called magma. Heat is continuously produced there, mostly from stored heat, friction, and the decay of naturally radioactive elements such as uranium and potassium.

The amount of heat within 33,000 feet of the earth's surface contains 50,000 times more energy than all of the oil and natural gas resources in the world!

The most common way of extracting energy from geothermal sources is to tap into naturally occurring hydrothermal convection systems where cooler water seeps into the earth's crust and is heated up before rising to the surface.

Geothermal power plants drill holes into this heated rock to capture this naturally created steam and then use the steam to drive a traditional turbine/generator system to create electricity. Geothermal fluid temperatures should be at least 300 degrees Fahrenheit, although geothermal plants are operating on fluid temperatures as low as 210 degrees Fahrenheit.

There are three main designs for geothermal power plants: dry steam, flash, and binary cycle. The ideal type of system for any particular site depends on temperature, depth, and the quality of the water and steam in the area. All three systems take hot water and steam from the ground, use the steam to generate electricity, and then return the warm water into the ground to prolong the life of the heat source.

Geothermal power plants are currently generating electricity in over 24 countries worldwide with a total output of about 8.9 gigawatts (which is enough electricity to power more than 6 million homes). The United States is the world's largest geothermal energy producer with output of about 2.8 gigawatts
By Nitram Tulp

Geothermal Heat Pump-Will the Geo Thermal Energy Generation at the Salton Sea Cause the Surrounding Areas to Sink?

Many people don't realize this, but the harvesting of geothermal energy to run steam turbines to make electricity has some drawbacks. You see, the heat from the earth helps push up tectonic plates, as it expands the ground. If you remove the heat, then it causes the area to sink down a little bit. This can be a tremendous problem for underground water mains and pipes. It can also cause seismic events to occur. When we say seismic we mean earthquakes. Oh, so now I've got your attention.

That's good because this is a very serious issue. Currently, there is a geothermal energy generation plant near the Salton Sea in California, and they are taking lots of energy, heat from the earth and converting it into electricity. Then the electricity goes through a high tension power lines all the way along the I-10 corridor to Los Angeles. Yes, even those folks in California use lots of energy; don't let all their talk of green alternative energy fool you.

Still, it could be said that geothermal energy is alternative energy. But a lot of people don't know that when you take heat out of the ground it takes a while to replenish that heat. If you take too much, too quickly, the Earth doesn't have time to replace it. And this is when the pressure is released and the ground sinks down. This can also cause an earthquake, or in some instances relieve pressure and prevent an earthquake.

Therefore, if you take the heat energy from the earth in just the right place you can prevent earthquakes and get free energy. That is, if you take just the right amount of energy and not too much. All this is pretty interesting isn't it? Still, the issue of the ground sinking can also be a problem, especially if you own a home that is on the settling ground. I sure hope you will please consider all this.





By Lance Winslow

Geothermal Heat Pump-Looking To The Past Of Geothermal Energy

Geothermal energy is often viewed as a relatively new form of alternative energy. In truth, the use of geothermal energy stretches far back into the past.

Looking To The Past Of Geothermal Energy

Geothermal energy is literally, “earth heat”. This type of energy's name comes from two Greek words: “geo” meaning earth, and “therme”, which means heat. While it may seem that the use of geothermal energy is a relatively new idea, it is actually an ancient practice. Many different cultures have used geothermal power to their advantage, dating back to some of the Earth's earliest civilizations.

In order to use geothermal energy, the energy source itself must be tapped into. Geothermal energy comes from reserves of water located in the Earth's layer of magma. Magma, otherwise known as molten rock, is a super hot substance that springs directly from the Earth's core, which is a scalding 9,000 degrees Fahrenheit. Magma heats the reserves of water located in its midst to very high temperatures, around 700 degrees Fahrenheit. These geothermal reservoirs, as they are known, can be drilled into or can escape naturally through cracks in the Earth's crust. These natural formations create such places on Earth as hot springs and geysers.

Geothermal energy can be traced back to 10,000 years ago when Native Americans used geothermal water found in hot springs to cook and for use as medicine. The geothermal energy found in hot springs was also used by the Romans. The ancient city of Pompeii used geothermal energy to heat homes. Romans also were known to use geothermal water for its medicinal properties; such as in the treatment of skin and eye diseases. Romans and other ancient civilizations also used the soothing geothermal waters found in hot springs for relaxation and natural bathing places. In more recent times, France started using this type of energy in the 1960's to heat their homes. More than 200,000 homes in France are now heated by geothermal water.

Scientists and other researchers are constantly coming up with new ways to use the Earth's latent powers. While geothermal energy has not yet shown us all it can do, it is evident that many cultures have enjoyed its power already. From the comfort of a hot springs bath to the warmth of a geothermal water heated home, the Earth has just begun to use the energy contained within its crust.

By Richard Chapo

Geothermal Heat Pump-You Decide - Weighing the Pros and Cons of Geothermal Energy

There has been an ongoing debate pertaining to the pros and cons of geothermal energy. Before we can begin to discuss the advantages and disadvantages, we need to have a clear understanding of what exactly geothermal energy is.

4,000 miles below the Earth's surface is incredibly hot. It is thought to be over 7,000 degrees Fahrenheit. While this temperature is extremely dangerous and must be avoided, if you were to drill about 3 or 4 miles below the Earth's surface, you can find a hot rock that is far less dangerous, and it is at only 300 to 400 Fahrenheit. This rock and heat can be used as a constant source of heat but would prove to be very expensive.

Now while drilling and using this hot rock can be extremely expensive, there are other alternatives. In some places, only a few hundred feet below the surface there are areas that have combined this hot rock and underground water to produce hot water streams. This is the most economic source of heat below the earth and can be used in a number of ways. The heat can be used to heat homes, businesses and even run large farms or provide energy for greenhouses.

The constant source of geothermal energy comes with a number of benefits and a number of concerns. These pros and cons mostly relate to environmental issues, overall cost and reliability.

In terms of environmental effects, the impact of geothermal energy has more benefits than disadvantages. Geothermal facilities do not emit any emissions and on the whole, these factories take up far less space than any gas plants that are used for the same process. This is because the facilities do not require any underground pipelines to distribute fuel. Essentially geothermal energy is a universal contributor to a cleaner, safer and healthier environment.

On top of the environmental benefits, geothermal plants are not only more efficient but are also very reliable. The system is much simpler all around and there are a lot less problems that can occur in maintaining the facility. There is also no waste disposal and transport of fuel required to run the factory and produce energy.

The main con when discussing geothermal energy is the overall cost. The start up cost for geothermal power plants is quite substantial and this is the main argument against the energy source. However the truth is that this initial cost is often compensated for rather quickly as operation costs are extremely low in comparison to other sources of energy. The costs of drilling and maintaining these plants are also decreasing steadily.

The technology used for geothermal energy is constantly improving and geothermal plants are becoming more readily available. There is no denying the technology involved and once we continue to lower the overall cost, there will be no limit to the benefits that we can take advantage of through the use of geothermal energy.



By Darren W.Chow

Geothermal Heat Pump-Energy Within - Using Geothermal Energy

This means of energy production uses the heat of the earth to generate power. Currently around 8,000 MW of electricity, with 2,800 MW in the United States alone. As with many other alternative sources,geothermal shows great potential. In a report released last year, the U.S. Geological Survey estimates that the geothermal potential in the U.S. alone is between 95,000 and 150,000 MWe (megawatts of electric power). A report issued just last year by MIT estimates the world's geothermal potential using Enhanced Geothermal Systems (EGS) at more than to be over 13,000 ZJ (a zettajoule is 1021) of which over 200 ZJ would be ex tractable with current technology.

Geothermal Technology

There are two basic types of geothermal power plants currently in use. Steam plants can use the hot water and very hot steam (over 300F) to power a turbine that feeds a generator directly ("dry steam") or they can depressurize the very high-pressure and temperature water to create steam ("flash steam"). The only emission in enough quantity to be significant is steam, although minute amounts of CO2, NOx and sulfur are released (in amounts almost 50 less than the amounts emitted at fossil fuel plants). Currently steam plants can generate electricity for about 4 cents to 6 cents per kWh.

Binary plants can operate at locations with lower temperatures ((100 F to 300 F), which is more readily available. Hot water passes through aheat exchanger along with a working fluid that has a lower boiling point (e.g., isobutene, isopentane). The working fluid vaporizes, turning the turbines and powering the generators.

Because this system is a closed loop, there are no emissions. Currently steam plants can generate electricity for about 5 cents to 8 cents per kWh. Because the lower-temperaturegeothermal locations are more plentiful, most plants are binary.

Geothermal energy can also be used a direct heat source. Nearly all the houses in Iceland are heated with water from hot springs, and the country generates more than half its energy fromgeothermal sources. If the heat is there but the water is not, energy can still be extracted. Pumping water through hot rock heats the water and can be used directly or to generate power.

Underground heat pumps are also a form of geothermal energy, these work like refrigerators in reverse. Believe it or not, you don't have to dig very deep to find the level of earth that stays at a fairly constant temperature - usually about 8 feet.Heat pumps use pipes (buried well below the frost line) that circulate a refrigerant through a cycle of condensing and evaporating between twoheat exchangers. One heat exchanger evaporates at low pressure and absorbs heat . A compressor pushes the refrigerant vapor, now at high pressure, to other coil where the refrigerant condenses and releases theheat. Unlike refrigerators and air conditioners, heat pumps can work in both directions-heating and cooling. Energy cost savings with a ground-based heat pump are substantial.

Geothermal Power Advantages

1.Geothermal energy produces little or no emissions.
2. In most cases, the "fuel" is free, although with the "hot rock" method water must be used, and may have to be transported there. Once the power stations are built they cost very little to operate.
3.Geothermal power plants usually have a small footprint, and very little environmental impact.
4.Ground-based heat pumps can be used almost anywhere. If you're thinking that they won't work in your snowy neck of the woods, consider that they are used extensively in Canada.

Geothermal Power Disadvantages

1.Geothermal cannot be considered a renewable resource (although it is a sustainable one).
2.Not every area has accessible geothermal sources. The hot rocks and water must be within drilling range (except in the case of natural geysers).
3.Geothermal sites can run out of steam, as their temperatures drop to low. This can happen naturally or if a "hot rock" extraction method is mismanaged, and the water injected cools the rocks.
4.Along with the hot water and/or steam, geothermal sources can also yield up harmful gases and minerals.
5.Drilling deep into the ground, especially when water is then pumped into the holes, can set off "small seismic events" - earthquakes.
6.While research can suggest likely places for geothermal power plants, there is no guarantee a given site will produce enough energy to offset the capital expenditure and operating costs.

What Can You Do?

Ocean and earth power gives you a lot of options. We've collected the ideas from this chapter-hydropower, tidal power, wave power, ocean thermal conversion, andgeothermal power- at the end to remind you of the variety, and to reinforce the idea that while there is no single perfect alternative energy source for the world, or even the country, there are many that in combination could be the perfect solution for you. Much depends on where you live and what resources you have.

1.If you have a river, stream, brook, waterfall or some other running water nearby, look into installing a micro hydro system to generate some or all of your electricity.
2.If you live on a body of water that experiences tides, you may be able to use them to your advantage. Naturally you won't be damming up estuaries to power your house (your own personal tide mill), but it is possible that you could implement something on a much smaller scale that powers, say, your dock lights. Realistically, however, what you'll be doing is keeping up with the technology so you'll know when someone has developed something with a more personal application.
3.While none of the wave power technologies are available as personal-size power stations, if you live somewhere that has strong, consistent waves, you may be able to adapt some of the techniques.
4.While you probably don't have a geyser in your yard, you might be able to install a ground-based heat pump to heat and cool your house.

By Kevin Rockwell