Tapping power from down under

By Henrylito D. Tacio
Amid the threat of a global energy crisis attributed to rapid depletion of non-renewable energy resources such as coal, oil, and natural gas, geothermal energy is considered a highly potential solution.
Aside from geothermal power, the Philippines is also moving to tap other renewable energy sources such as biomass, hydropower, solar power, wind power, and ocean energy in order to supply up to 40 percent of its ever-growing power needs in the coming years.
The Philippines has been using geothermal energy to sustain its energy needs for over 40 years.  Next to the United States, the Philippines has the second highest geothermal power capacity in the world today.  Its geothermal power on its islands is more than double its current output.
According to some records, the country’s current existing capacity of geothermal energy is 2,027 megawatts (MW).  An additional 1,070 MW has been targeted by the energy department.  By 2030, the country will be using 3,097 MW of energy from geothermal power alone.
Electric power is measured in units called watt.  A watt is equal to one joule (the quantity of energy that can be generated from a fuel such as oil or gas) per second.  The total generating capacity of a power plant is measured in kilowatt (KW) for 1,000 watts, and megawatt (MW) for one million watts.
Geothermal energy is considered a renewable energy source since its supply is considered inexhaustible.  The word “geothermal” comes from the Greek roots geo, meaning “earth,” and thermos, meaning “heat.” 
The inner core of the earth consists of a molten mass that acts as the source of geothermal energy.  In some areas of the Philippines and throughout the world, the intense heat within the earth occurs near the earth’s surface and heats underground water, forming hot water or steam.
If these reservoirs are close enough to the surface, wells can be drilled to tap the steam and hot water.  The steam and hot water is used to produce electricity with generators.  (Geysers occur where these reservoirs of steam and hot water naturally break through the surface.)
History records showed that the world’s oldest geothermal district heating system is in Chaudes-Aigues, France, which has been operating since the 14th century.   But the earliest industrial exploitation began in 1827 with the use of geyser steam to extract boric acid from volcanic mud in Larderello, Italy.
A Wikipedia report said a deep geothermal well was used to heat greenhouses in Boise, Idaho in the United States in 1926, and geysers were used to heat greenhouses in Iceland at about the same time.   Since 1943, Steam and hot water from geysers were used to heat homes in Iceland.
The 20th century saw the rise of electricity, and geothermal power was immediately seen as a possible generating source. Prince Piero Ginori Conti tested the first geothermal power generator on July 4, 1904, at the same Larderello dry steam field where geothermal acid extraction began. It was a small generator that lit four light bulbs.  Later, in 1911, the world’s first geothermal power plant was built there. It was the world’s only industrial producer of geothermal electricity until 1958, when New Zealand built a plant of its own.
The first commercial geothermal heat pump was designed by J.D. Krocker to heat the Commonwealth Building in Portland, Oregon in 1946.  Two years later, Professor Carl Nielsen of Ohio State University built the first residential heat pump two years later.  The technology became popular in Sweden as a result of the 1973 oil crisis, and has been growing slowly in worldwide acceptance since then.
In 1967, Dr. Arturo P. Alcaraz and his team lit a light bulb using steam-powered electricity coming from a volcano near the town of Tiwi in Albay.  This was the first geothermal power generated in the Philippines.
Through the hard work of Dr. Alcaraz – who touted to be the Father of Geothermal in the country – the firstgeothermal power generating plant with a three megawatt capacity was opened in Leyte in 1977. By 1980, thegeothermal plants in Tiwi and Mt. Makiling-Mt. Banahao (called Mac-Ban) were each capable of producing 220 megawatts, and in the first half of 1982, when another 110 megawatts were added at Tiwi, the Philippines attained the second highest geothermal generating capacity in the world.
(In 1982, Dr. Alcaraz was bestowed the prestigious Ramon Magsaysay Award for Government Service “for scientific perspicacity and selfless perseverance in development of Philippine geothermal energy”.)
Today, geothermal electricity is generated in 24 countries around the world including the United States, Iceland, Italy, Germany, Turkey, France, the Netherlands, Lithuania, New Zealand, Mexico, El Salvador, Nicaragua, Costa Rica, Russia, Indonesia, China, and Japan.
Geothermal power is environment-friendly.  It requires no fuel, and is therefore immune to fluctuations in fuel cost.  In fact, the production of the electricity by geothermal plants is cheaper than the electricity produced in plants by using natural gas and coal. It is even cheaper than electricity produced by hydro power stations.
Geothermal has minimal land use requirements; existing geothermal plants use 1-10 hectares per megawatt versus 5-12 hectares per megawatt for nuclear operations and 25 hectares per megawatt for coal power plants. 
On the negative side, geothermal power still creates some environmental problems.  Studies have shown thatgeothermal fluids drawn from the deep earth may carry a mixture of gases with them, notably carbon dioxide and hydrogen sulfide. 
When released to the environment, these pollutants contribute to climate change, acid rain, and noxious smells in the vicinity of the plant.  According to studies, existing geothermal electric plants emit an average of 90-120 kilograms of carbon dioxide per megawatt hour of electricity.  But this is just a small fraction of the emission intensity of conventional fossil fuel plants.  In some parts of the world, some geothermal power plants are equipped with emissions-controlling systems that reduces the exhaust of acids and volatiles.
In addition to dissolved gases, hot water from geothermal sources may contain trace amounts of dangerous elements such as mercury, arsenic, and antimony which, if disposed of into rivers, can render their water unsafe to drink. Geothermal plants can theoretically inject these substances, along with the gases, back into the earth, in a form of carbon sequestration.