How Does Geothermal Energy Become Electricity

The main forms of renewable energy that most people see and hear about are solar energy and wind power, but there is another major power source that will soon be demanding attention. It has already been used to provide power to 1.2 million homes in the United States. It has far greater potential and to both heat and provide electricity to homes and is yet to be properly utilized. That's about to change.

Geothermal energy comes from a variety of sources of heat within the earth: the planet core, decay of naturally occurring substances within the crust and movement of continental plates as they slide against and underneath each other. Volcanoes, hot springs and steam vents represent the easily accessible points to this energy but most geothermal energy is trapped under the earth’s crust and must be accessed by drilling into the resource and harnessing the energy. The thermal energy in the uppermost 6 miles of the earth’s crust contains 50,000 times the energy of all the world’s gas and oil resources.

What Is Geothermal Energy?

Geothermal energy is the heat stored below the earth’s surface. In some parts of the world where the earth’s surface is cracked or thin, steam and molten rock can escape. These are usually locations of high seismic activity such as earthquakes and volcanoes. If water finds its way into these cracks, it becomes heated and may come to the surface as geysers, fumaroles, hot springs and mud pots.

Parts of USA, New Zealand, Japan and Europe have high geothermal activity. Electricity is generated using high grade geothermal energy such as geysers, mud pots, hot dry rocks and fumaroles. Geothermal energy can also be used as a heating source, for example in Iceland hot water is brought to the surface through a bore , then sent through insulated pipes into homes and radiator panels which provide heat. Over 80% of homes in Iceland are heated this way.

Although geothermal energy doesn’t pollute the air with greenhouse gases, there are other environmental concerns about its use. Scientists are not sure how the long-term use of this resource could affect our underground water supplies. Some geothermal tourist attractions at Rotorua in New Zealand have already suffered a decline in surface activity due to the draw-off of geothermal fluid from the underground reservoir by domestic and commercial uses.

Geothermal energy can be broken down into 4 main types – Geothermal energy can be broken down into 4 main types – hot dry rock, geopressured, hydrothermal and magma.

Hydrothermal

Hydrothermal is the only source used to generate commercially viable energy and is derived from hot water and steam formed in porous or fractured rock at relatively moderate depths from 100 metres to 5 kilometres.

The hot water and steam come from the intrusion of molten magma into the earth’s crust or the deep circulation and heating of groundwater through faults and fractures.

To generate electricity, hot water at temperatures ranging from 180 – 250 degrees Celsius is brought from the underground reservoir to the surface through production wells and is flashed to steam in special vessels by release of pressure. The steam is separated from the liquid and fed into a turbine engine which turns a generator. Ensuring the water levels are not depleted, the used geothermal water is returned to the reservoir.

Geopressured

Geopressured energy is derived from hot, pressurised waters containing dissolved methane, trapped at depths of three to six kilometres in sedimentary formations. The water temperature ranges from 90°C to 200°C.

Energy in 3 forms can be derived from geopressured sources – thermal energy from the hot water, hydraulic energy from the high pressure, and chemical energy from burning the dissolved methane.

Magma

The prospect of using magma directly has still not been exploited. Found at depths from between 3 and 10 kilometers below the earth's surface, magma is molten rock reaching temperatures up to 1200°C. Magma is only accessible where volcanic activity or tectonic plate movement occurs.

Hot Dry Rock

In certain cases granite at a depth of 3 to 5 kilometers under the earth's surface can get to 250°C. Unlike hydrothermal resources, the fractures and faults required to conduct water to the surface are not present, therefore water must be pumped into the rock at high pressure to create an artificial underground reservoir of steam or hot water.

A number of development projects continue into attempting to make use of hot dry rock to create electricity but factors such as cost and questions about resistance of the reservoir to flow, water loss and thermal drawdown remain. As the cost of producing geothermal using hot dry rock technology keeps coming down it will soon be an economically viable option.

The Future Prospect of Geothermal Energy in the US

An exciting new development in the future of geothermal energy in the United States has just been announced by the Department of the Interior who have promised to make 190 million acres of federal land available for geothermal power development. This is good news because the proposed land includes no environmentally sensitive areas such as national parks or designated wilderness areas.

An estimation of something like 5,500 MW of electricity from geothermal power will be generated by 2015. It’s a positive move that will promote a form of renewable energy that has been used for years, but perhaps not to its full potential.

CSP - Solar Thermal Electricity

There are predominantly two types of solar power generation methods used to produce electricity on a commercial scale. Photovoltaic panels uses the sunlight to directly produce electricity by using solar cells set in photovoltaic modules. Concentrating solar power (CSP) uses thermal solar power, the heat of the sun, to produce environmentally friendly energy.

It’s the way in which concentrating solar power plants produce electricity that we will concentrate on here. CSP plants are capable of producing electricity at a higher maximum capacity than a photovoltaic facility of the same size. As renewable energy becomes more prevalent, we will see more concentrating solar power plants get developed.

The four main comercially productive concentrating solar power systems are: parabolic troughs, dish / engine systems, fresnel reflectors and central receiver systems. Each of these technologies have been proven and are currently in operation around the world with more developments in solar power in progress to increase global capacity.

Parabolic troughs use mirrors to direct sunlight onto a fluid-filled receiver positioned in directly in front of each trough. The heat generated from this process heats the fluid to high levels so that super-charged steam is created. This steam is then directed into a conventional steam generator to produce electricity.

A trough-based CSP plant typically consists of rows of mirrored troughs placed parallel to each other along a north-south axis in what is known as a collector field. The troughs pivot as they follow the sun to ensure that it is continuously focused on the receiver tubes. Thermal storage is also used to allow electricity generation to continue even when the sun is not available. Technological advancements are continuing to prolong this production period in a bid to move to continuous solar electricity production.

Power plants known as Andasol 1, Andasol 2 and Andasol 3 in Spain all use the parabolic trough design, forming a combined 150MW solar power plant. The surface area of the mirrors used to form the energy collection field of Andasol 3 alone is around 500,000m2.

Fresnel reflectors provide a more concentrated focus of solar energy onto centrally placed receivers. This is a simpler system to the parabolic trough system with fewer moving parts and the rows can be positioned closer together. The receiver is stationary and it is shared by several mirrors.

An example of a recently commissioned CSP plant using reflector technology is the Kimberlina CSP plant in California developed by Ausra. This power plant is relatively small at only 5MW capacity, but it paves the way for future large-scale developments.

Dish / engine systems are stand-alone units that contain dish-shaped parabolic mirrors that concentrate the sun’s energy onto a receiver mounted above the dish. From there the energy is converted into mechanical power and electricity is generated similar to the way a mechanical engine runs. Each dish / engine unit has a capacity of around 25kW of solar power and it tracks the sun to ensure optimum power.

An example of the dish / engine technology is the Stirling Energy Systems dish called the Suncatcher. It will be used in fields of thousands to form a power facility capable of generating over 500MW of electricity.

Central receiver systems are also known as power towers. Looking as though they're honoring a higher deity, thousands of mirrors called heliostats cluster around a receiver that sits on top of a tall tower. The heat that is collected by the receiver then heats molten salt as it flows through which is then used to make steam that operates a conventional steam generator. The molten salt can be stored for great lengths of time which means that this type of solar energy generates electricity continuously around the clock.

Solar One, Solar Two and the latest power tower, Solar Tres are all examples of central receiver systems. The Solar Tres power plant will be a 15MW facility and it follows on from the successful demonstration power plant known as Solar Two which was located in the Mojave Desert.

Opponents of solar energy cite cost as a limiting factor, but this is being overcome thanks to technological advancements. Already, concentrating solar power plants hold a huge advantage over the traditional fossil fuelled counterparts in the lower impact to the environment. In fact, one of the only impacts that concentrating solar power plants have on the environment is land use.

There continues to be solid progress made in ways in which renewable energy is used to replace traditional energy sources. Concentrating solar power has proven to be a renewable energy source with still more untapped potential

Reduce, Reuse, Recycle: We need to each do more... our planet depends on it

http://www.rustic-lodge-lifestyle.com/index.html

We live in a throw-away society

We're wasteful. Not just on an individual level, but on a much broader scale as well. Our lifestyle is just not sustainable in terms of the world's resources we consume.

The subject of unnecessary waste in our society came sharply into focus for my wife and me over the last couple of years due to numerous trips to take garbage to the county dump.

When we were renovating our cabin we took construction scrap to the dump on a regular basis (along with our wet garbage). We began to notice a considerable number of perfectly good items that had been thrown out. After observing this for a while (and rescuing numerous perfectly good items along the way), we started to ask, "What can we do about it?"

We changed our lifestyle to reduce, reuse, and recycle. Although we may think we can't make a difference individually, small steps taken on an individual level can and do make a difference. We must each do our own small part to minimize the waste and excess consumption in our society. Change is possible... indeed, it's absolutely necessary.

One of the most challenging aspects of taking steps in this direction is the constant bombardment from the media... the non-stop stream of powerful advertising attempting to convince us that we need the latest and greatest gadgets, toys, electronics, cars, and on and on. It's a powerful and extremely effective influence.

And it seems that, unfortunately, a lot of people are too lazy and/or simply don't think about the fact that something that they are throwing away could be used and appreciated by someone else. Nor do they think about the landfill being taken up by perfectly good and useful items.

Our dump experience spawned the idea of a series of short video vignettes that would highlight this sad situation. Yes, it's a serious topic, but we wanted to have a little fun with it in order to highlight the number of perfectly good items that we saw at the dump every week. Thus was born "Adventures with Fitzgerald the Dump Truck". The episodes can be seen on the Rustic Lodge Lifestyle home page.

What can you do?

Are you concerned about rampant consumerism and the corresponding waste? If so consider taking some of the following steps:

Turn off

Break free of the insidious power of commercials by limiting your exposure to them... and if you have children, this is even more important. Setting a good example is paramount in teaching the next generation that it is not necessary to have the newest, most recent model of everything!

Teach them that happiness does not come from a store! We don't expose ourselves to the onslaught of commercial messages. We rarely watch TV, we listen to public radio, and have very few subscriptions to magazines that come to the house.

Consequently we are blissfully unaware of so much of the product marketing and thus are not even tempted to rush out to buy this or that "must have" gizmo. We've never had a TV at our country lodge, so when the grandchildren visit, there is no temptation to watch it... it just isn't part of the "lodge experience".

Critically assess your habits

What are you throwing away? Get in the habit of looking critically at all of your household waste. Is it really garbage? Can it be put to good use by someone else? Can you compost your wet garbage? Are you recycling everything that is possible to recycle? We have two or three charities that call us regularly to ask if we have any donations they can pick up. Some of them let us know we can call them any time for an additional pickup of clothing and household items. Check for charities that offer this service in your area.

Taking this simple step would see items such as toys (we've seen full boxes of perfectly good stuffed toys at the dump - some brand new with the tags still on), other toys, bikes, chairs, lamps, tables and other furniture, and much more, put to good use.

Episode one of the "Fitzgerald" series highlights many of the items that we rescued from the dump. Other episodes show many perfectly good items that had been thrown away, but which we personally didn't take.

Challenge each other

Families can get together and set up challenges to minimize waste. At the office, organize a waste awareness day. Get your boss involved... or if you are the boss, you set the tone. Even neighborhoods can activate to increase awareness.

These are just a few suggestions to start the creative juices flowing. Each one of us must start taking individual responsibility to reduce the resource footprint on our fragile planet. Reducing our personal waste by limiting unnecessary consumerism, and through reuse and recycling are important actions we must all take.

Simple Steps to an Eco-Friendly Home

by Beverly Clarke

Everyone’s worried about the environment.The news shows it every day.  The planet is in trouble and we're running out of time.

You may be thinking that there's just no hope, with all of the bad news.One person doing something can't make a difference.  Don't despair.  There's still a lot that can be done starting with your eco-friendly home.

The first thing to do is to look around and see where you can cut waste.Requiring a huge amount of energy, which is very hard on the environment, is heating and cooling a home.  In the summer time, try closing curtains and using fans instead of the air conditioner.  Don't just mindlessly turn on the system on the first hot day of the year and leave it running for the rest of the season.It's important to be aware of the weather outside your door.Is turning on your AC really necessary, or can you manage without it.Often feeling better, is a warm breeze running through a room in place of a closed up cool one.

Layer on the sweaters and lower the thermostat is what you should be doing in winter.It feels good to wrap yourself in a warm and cozy blanket when you are reading or watching television.Better for the environment it certainly is and it's feeling good too.

The area of water usage is another where your home can be made to be more eco-friendly.Ultr low-flush toilets should be in place in your home.  Install low-flow shower heads and aerators on your sinks.Still doing the job well, these units use much less water.

Only when you have a full load of laundry or dirty dishes, is the time to be running your washing machine or dishwasher.  Anything less is wasteful.Why not hang your laundry out to line dry when it comes out of the washer?No matter what fabric softener you use, it can never be as clean-smelling as laundry that has been dired outdoors.

Speaking of fabric softener and other cleaning products, you might want to look through your collection and take the ones containing dangerous chemicals to the next hazardous waste drop off day.Using harsh cleaning chemicals is one of the biggest contributors to indoor air pollution.

General cleaning requires only vinegar, baking soda and hot water.Simply using a bit of dish soap to cut through grease, is all you need for a clean, safe home!

The eco-friendly home is not hard to achieve.The problem seems overwhelming, but remember that it took millions of bad choices to get us here.To get us out, will take millions of good ones.

Beverly Clarke is a writer and Interior Designer living in South Florida.Making a contribution to a cleaner world is in what she is most interested. She offers many facts and ideas on  how to help save our environment through the use of alternative fuels and by recycling just about everything.

Going Green? Read the Solar Energy Facts

We hear about solar energy on an nearly daily basis.  But are we hearing real solar energy facts or is there are lot of talk filled with opinions which cannot be backed up with hard evidence.  Since this is becoming a hot political topic there are many solar energy facts out there which are not quite as substantiated as we are lead to believe.

One of the reasons why solar power is so topical is because it is a renewable energy source.  This means that, unlike energy which is dug or drilled out of the ground, it is not going to run out. 

Another important solar energy fact is that it is a clean energy source.This means that it does not increase levels of hazardous greenhouse gases and it does not produce any other emissions which are currently believed to be dangerous to our ecosystem.

Solar energy facts concerning its versatility are a bit vaguer.  This is due to the current problems with efficiency and storage.  If you are considering converting to solar power completely you may want a solar powered car.  This is possible, but you will probably find that you are going to have a difference in performance levels between your traditionally fuelled car and your solar powered.  So it is true that you can have a solar powered car, but there will be sacrifices.

So if you wanted to go green and have everything solar powered, would it be possible?  Well, one important solar energy fact is that manufacturers are cashing in on the idea and they are pricing solar energy powered products much higher than traditionally powered similar products.

So is solar energy cheaper to run?  This is a maze of information and extracting the solar energy facts of this one is not easy.  Once solar energy systems are installed they are cheaper to run.The sun will shine for free and every time she shows her face you will be acquiring power to either use, store or sell.  In some areas you can sell your excess solar power back to your local energy supplier.  This all sounds very good, but there are a lot of upfront costs which you will have to recoup before you are making a profit, so don’t get too excited too quickly.  The only way to truly establish if you could run solar powered without breaking the bank is to get one of the solar powered companies to come and do a home assessment.  During this they will advise you of the work which would be required to convert your home to solar power.  This should include the cost parts and the amount of energy you are likely to be able to produce.  Most companies will be able to review your current energy use and be able to tell you if you will be short and need to top up with traditional sources of energy or if you will be selling back to the local supplier.

One solar energy fact you can be sure of is that solar energy is here to stay.  We just don’t know what percentage of our energy usage will be solar and how quickly this change over will happen.

Carbon Footprint Awareness Is Important

Many of us cruise through our daily lives completely oblivious to such things as a carbon footprint. The products we use have an impact on the crisis of global warming and add to the greenhouse gases emitted into the atmosphere. Our day to day lives are led in such a way that we simply don't have the time or inclination to stop and wonder how our actions affect the larger picture.

Here's just a personal example of how our energy use is taken for granted. Our multiple digital clocks run in our houses 24 hours a day – we’ve got one on the microwave, one on the conventional oven, one on the CD player, one on the stereo and one in each of our three bedrooms, all of them drawing passive energy and we don’t even give it a thought. It’s just one of the assumed “rights” of living in a modern affluent society, we may not use it but we don’t mind paying for it regardless. It may be a little shocking for some people to learn exactly what the level of carbon emissions they produce each year is, as well as the added costs they are incurring simply by being blase about the little things.

You Can’t Change What You Don’t Know

I like that sentence, it neatly sums up a whole range of human instincts and precisely describes one of the roadblocks in front of those trying to educate people on the importance of reducing our carbon footprint. It only takes a gentle reminder that there are consequences for the actions taken on a daily basis that people begin to realise that there is a need to change.

It's only when you find out that the yearly average carbon dioxide production for running a car stands at two and a half tonnes that it hits home that there may be a problem. It also allows you to then set a goal to lower your number for the next year. Now you have given yourself a goal that can be quantified with the possibility of aiming to achieve. Without the calculation of your carbon footprint you would be resigned to stating that you produce some (or a lot of) carbon dioxide. Trying to produce less in the future would be next to impossible to gauge.

The fact that there is also a corresponding cost benefit to reducing your carbon footprint size should have people flocking to the cause.The cost benefit in question is an actual dollar saving! Fortunately, the word is slowly getting out there while, with any luck, the levels of carbon dioxide aren't.