Fossil fuels facts

Fossil fuels are formed by the anaerobic decomposition of remains of organisms including phytoplankton and zooplankton that settled to the sea (or lake) bottom in large quantities under anoxic conditions, millions of years ago.

Fossil fuels are oil, coal and natural gas. In 2006 primary sources of energy consisted of petroleum 36.8%, coal 26.6%, and natural gas 22.9%, amounting to an 86% share for fossil fuels in primary energy production in the world.

Crude oil is a smelly, yellow-to-black liquid and is usually found in underground areas called reservoirs. Scientists and engineers explore a chosen area by studying rock samples from the earth. Measurements are taken, and, if the site seems promising, drilling begins.

Coal is a readily combustible black or brownish-black sedimentary rock normally occurring in rock strata in layers or veins called coal beds.

Natural gas is a gas consisting primarily of methane. It is found associated with fossil fuels, in coal beds, as methane clathrates, and is created by methanogenic organisms in marshes, bogs, and landfills.

Fossil fuels - current US energy picture.

Fossil fuels are non-renewable resources because they take millions of years to form, and reserves are being depleted much faster than new ones are being formed.

All fossil fuels are made of hydrocarbons. Hydrocarbons store energy in the form of the atomic bonds. Energy stored in hydrocarbons can be released very easy - we just have to burn them.

When fossil fuels are burned carbon and hydrogen react with oxygen in air to carbon dioxide (CO₂) and water (H₂O). During this reaction heat is released which further amplifies the reaction.

One of the biggest benefits of fossil fuels is their cost. Coal, oil and natural gas are abundant right now and relatively inexpensive to drill or mine for.

At current usage, the coal supply will last 1500 years. However at a 5% growth rate the coal supply will last only 86 years. We can expect even greater usage as other fossil fuels become scarce.

Coal energy yield depends on how much carbon is contained in it. Two types dominate US reserves. Anthracite is 95% carbon and is approximately 300 million years old. Lignite is 25% carbon is nearly 150 million years old.

An oil refinery is an industrial process plant where crude oil is processed and refined into more useful petroleum products, such as gasoline, diesel fuel, asphalt base, heating oil, kerosene and liquefied petroleum gas.

To run a 100-watt light bulb 24 hours a day for a year we need to use about 714 pounds (325 kg) of coal in coal powered power plant (thermal efficiency of such power plant is typically abut 40%).

Fossil fuels are also overwhelmingly responsible for fueling our transportation system. Petroleum-based fuels are the standard.

One liter of regular gasoline is the time-rendered result of about 23.5 tonnes of ancient organic material deposited on the ocean floor.

The total fossil fuel used in the year 1997 is the result of 422 years of all plant matter that grew on the entire surface and in all the oceans of the ancient earth.

Burning fossil fuels is responsible for environmental issues that are high on the political agenda these days. Examples are greenhouse gas accumulation, acidification, air pollution, water pollution, damage to land surface and ground-level ozone.

Consequence of oil spills. Fossil fuels cause direct and indirect pollution.

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China to double hydropower capacity in one decade

China has many times expressed desire to stop being used as the synonym for pollution due to heavy industrialization and the excessive use of fossil fuels, most notably coal. China is still heavily dependent on fossil fuels but is also investing huge resources into its renewable energy sector in order to become greener in years to come. One of the most dominant renewable energy sectors is definitely hydropower.

China's hydropower capacity is currently somewhere around 172,000 megawatts, which is the largest in the world, mostly due to different hydropower project like Three Gorges Dam. But china isn't planning to stop at this level and is in fact expected to nearly double its hydropower capacity to 300,000 megawatts by 2020. At least this is what state media said, as the nation powers ahead with the development of renewable energy sources.

Three Gorges Dam.

Water resources minister Chen Lei, who was quoted by the official Xinhua news agency as giving the target, also said hydropower would play a more important role in China's strategy for energy security in the future. Of course it still remains to be seen whether future Chinese hydropower project will be built with less problems than lest say China's infamous Three Gorges Dam that in the end turned out to be more negative than positive project despite huge potential.

One thing is sure though China definitely needs more developed renewable energy sector, and hydropower projects if properly done could be of great help to China to become greener and stop being labelled as the world's biggest poluter that contributes mostly to climate change problem.

If we take a look at the current China energetic data we can see that China is still heavily dependent on highly-polluting coal that satisfies 70 percent of its energy needs. China would definitely like to change this ratio and is therefore giving tremendous economic boost to some renewable energy sectors, most notably wind and hydropower energetic projects.

Of course China isn't only doing this to save its environment and global climate, there is also the question of energy demand that will become even bigger in years to come. Any energy source that has enough potential should be exploited as much as possible, especially if this energy source turns out to be ecologically friendly energy source.

China can definitely use its huge hydropower advantages but should also learn a lot from past mistakes to ensure prominent place for hydropower sector in future energy supply.

China's hydropower sector had its peak in 80s, and was even referred to as the "country's only renewable energy that could be tapped on a large scale" but some problems with the construction of Three Gorges Dam stopped China's hydropower miracle. It will be really interesting to see whether hydropower still has enough to jump back as the best alternative to fossil fuels in China, and whether Chinese has learned something from their past mistakes.

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Geothermal energy - Technology and power plants

There are two basic types of geothermal power plants currently in use, steam plants and binary plants. Steam plants use the hot water and very hot steam (with temperatures over 300F) to power a turbine that feeds a generator directly (if this is a "dry steam" principle) or they can depressurize the very high-pressure and temperature water to create steam ("flash steam" principle). Currently steam plants can generate electricity for about 4 cents to 6 cents per kWh.

Binary plants have one advantage over steam plants, namely that they can operate at locations with lower temperatures ((100 F to 300 F), which makes them available at much more places than steam plants. This is also the reason why there are much more binary plants than steam plants Hot water passes through a heat exchanger along with a working fluid that has a lower boiling point (such as isobutene). The working fluid vaporizes, moving the turbines and powering the generators.

Geothermal power station. Click on the picture for full size.

As said before geothermal energy can also be used a direct heat source. If we take a look at Iceland we can see that all the houses in Iceland are heated with water from hot springs, and Iceland currently generates more than half its energy from geothermal sources.

We should also mention underground heat pumps that are also a form of geothermal energy. Underground heat pumps have very interesting working principle, namely they work like refrigerators in reverse. Heat pumps use pipes (that circulate a refrigerant through a cycle of condensing and evaporating between two heat exchangers. One heat exchanger evaporates at low pressure and absorbs heat. A compressor pushes the refrigerant vapour, now at high pressure, to other coil where the refrigerant condenses and releases the heat. Unlike refrigerators and air conditioners, heat pumps can be used for both heating and cooling.

Conclusion

Geothermal energy is definitely one of the energy sources we should be using more in years to come. Of course, in order for this energy source to become cost competitive there are still lot of researches needed to decrease currently high installation costs, and to find methods to improve efficiency. Given that is environmentally friendly energy source we should be definitely working more on methods to exploit it as much as possible. Many positive examples have so far proved that this energy source has huge potential and it would really be a shame if we won't do anything to expand its use, especially now when world seeks for alternative energy sources to combat climate change and pollution.

Geothermal energy overview:
1. Geothermal energy - Quick overview
2. Geothermal energy - How to use
3. Geothermal energy - Advantages and disadvantages (previous)
4. Geothermal energy - Technology and power plants (current)

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Geothermal energy - Advantages and disadvantages

In order to better understand the whole geothermal energy concept we also need to point out advantages and disadvantages of this renewable energy source. First we'll start with the geothermal energy advantages.

Direct use of geothermal energy is definitely one of geothermal energy advantages. Since ancient times, people have used geothermal power directly for purposes of taking baths, preparing meals, and today this renewable source of energy is primarily used for heating homes or buildings mostly through the use of district heating systems. These heating systems pipe hot water into buildings from the surface of the earth, and are available for immediate use.

Geothermal energy is ecologically acceptable renewable energy source because of low greenhouse gas emissions. The biggest problem with fossil fuels is that they during combustion release harmful emissions to our environment. This results in not only climate change problem, but also in acid rain and other pollutants. Geothermal energy releases negligible emissions compared to fossil fuels. In most cases, the "geothermal 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.

Ground-based heat pumps can be used almost anywhere. For instance even snowy Canada uses them.

Geothermal energy advantages - cheap cooling.

Geothermal energy advantages - cheap heating.

Geothermal energy is also renewable energy source, and this means that this energy source won't disappear after some time. Geothermal energy can constantly be at our disposal because the earth continually replenishes our water supply through rain, and the earth's interior is in a constant state of producing heat. When we combine this we get the energy source capable of both heating as well as cooling homes that is constant and is doing no damage to environment.

Like with all other energy source geothermal energy also has some disadvantages that we should be mentioning. So here are few of them.

Geothermal energy isn't widely spread source of energy and most countries do not make use of geothermal energy, which in many cases results in difficulties during the geothermal system installation in your home or office because it is hard to find qualified personnel for the job, and even if you find them they cost you lot.

There are also some difficulties during the installation process because in order to install geothermal system requirements are usually wide spaces and long pipes. This of course can be quite tricky to do in areas with very dense population.

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.

Not every area has accessible geothermal sources. The hot rocks and water must be within drilling range (except in the case of natural geysers).

There is no guarantee a given site, regardless of its location, will produce enough energy to offset the capital expenditure and operating costs.

Geothermal energy overview:
1. Geothermal energy - Quick overview
2. Geothermal energy - How to use (previous)
3. Geothermal energy - Advantages and disadvantages (current)
4. Geothermal energy - Technology and power plants (next)

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Geothermal energy - How to use

Using geothermal energy has very long tradition in human history. For instance people in ancient times have used geothermal energy for hot springs, cooking, bathing and heating purposes. Basically there are three primary ways to use geothermal energy:

• The heat from the Earth could be used directly for heating systems in houses or buildings. The hot water close to the Earth's surface can be directly pumped into heating systems ensuring adequate supply.
• Generators in power plants require steam at extreme temperatures to operate. Therefore geothermal power plants are built near reservoirs to ensure better efficiency. Geothermal power plants use steam or hot water close to the surface to increase efficiency of standard thermal power plant, and this is how electricity is generated.
• Geothermal heat pumps are also used in exploiting geothermal energy. These pumps use water near the Earth's surface to control building temperatures.

Geothermal heat pump system. Click on the picture for detailed view.

Country that uses geothermal energy the most is Iceland. For instance in Reykjavik, Iceland's capital, 95 percent of the buildings is heated with geothermal district heating systems. Of course this can't be achieved anywhere in the world and Iceland is really using tremendous geothermal energy potential to ensure enough heat for both households, as well as buildings and industries.

Geothermal energy overview:
1. Geothermal energy - Quick overview (previous)
2. Geothermal energy - How to use (current)
3. Geothermal energy - Advantages and disadvantages (next)
4. Geothermal energy - Technology and power plants

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Geothermal energy - Quick overview

As the energy demand keeps on growing many people have started looking for more and more ways to find different renewable energy sources. Despite growing popularity of geothermal energy over the years many people still don't realize they are standing on top of one of the greatest energy resources on the planet. The Earth's core is full of heat, and heat builds up tremendous pressure in the Earth's core that simply has to be released in some way. These energy releases from Earth's core are known as geothermal energy, usually in form of hot water and hot steam. The hot water and steam from the Earth can be used in a variety of different ways to create energy. Geothermal energy is called renewable energy because the heat in the Earth's core is constant.

Geothermal spring - water and steam from the Earth can be used in a variety of different ways to create energy.

Today people have started talking much more on possible ways to save fuel and how to find more energy efficient ways to satisfy our daily energy demand. Geothermal heat and energy are definitely one of the renewable sources with biggest potential because of its natural origin. By using geothermal energy we are basically using the natural energy stored in the earth's core to power our homes and buildings. Geothermal energy also has many positive environmental effects such as it helps reduce global warming but we will talk more about it later.

Geothermal energy overview:
1. Geothermal energy - Quick overview (current)
2. Geothermal energy - How to use (next)
3. Geothermal energy - Advantages and disadvantages
4. Geothermal energy - Technology and power plants

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China - Solar energy to dominate renewables

China is world's biggest polluter, and country that has become a synonym for pollution so it is really no surprise that China is mobilising its renewable sector in an effort to make the economy greener and decrease pollution across many Chinese cities. Therefore the Chinese government has offered solar companies support policies including land, bank loans and research fund in order to further boost solar energy sector.

Many people do not know that China has the world's largest rooftop solar power station, located in Weihai City of Shandong province. The 330-kilowatt project uses technology that China holds the intellectual property rights of.

Early this year, the Chinese government has offered a series of favourable policies to support solar energy development. It gives generous subsidies up to about 50 percent of the construction price for demonstrating a roof-top solar power system. Government is also giving its best to ensure favourable polices for solar energy companies, including advantages such as free land, cash for research and development, and lately also very favourable bank loans with low interest rates.

Wang Zhongying, Director of Renewable Energy Development Center of NDRC said "Although the cost for solar power is still high in the near term, in the longer term, many experts think the future belongs to solar energy." This is very true from economical point of view because for instance coal is much more affordable energy source compared to solar energy, but it is also important to look at things from environmental point of view to see benefits of solar energy. With more researches and enough funds solar energy has big potential to become cost competitive with fossil fuels in years to come, and help decrease pollution and climate change effect on global level.

Dahan - China’s First Solar Power Plant - The plant should be completed and running in 2010 with plans to expand it into a five to ten megawatt plant over the following five years.

Chinese companies have already played a leading role in pushing down the price of solar panels in the world's market by almost half over the last year that has significantly contributed to popularity of solar energy sector. And a growing list of Chinese corporations backed by entrepreneurs and local governments are seeking to capitalise on an industry deemed crucial for the country's commitment to a greener country.

Of course this doesn't mean that China is giving up on fossil fuels, most notably coal. Coal is still the most dominant energy source in China, and is very likely that fossil fuels will dominate China's energy sector for at least couple of decades before renewables like solar energy sector become truly competitive. In any case China's efforts to become greener economy by boosting its solar energy sector are really welcome not only for general development of renewable energy sector but also to decrease pollution and fight climate change on global level.

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