Alternative Energy: Today and Tomorrow
By Donald Kaiser – March 1, 2011
Introduction and Background
Crude oil or black gold is the industrial world's primary energy source and it accounts for approximately 40% of total energy use. With the additional use of coal (~25%), natural gas (~25%), nuclear (~5%), and hydroelectric power (~5%), very little of our total energy use comes from alternative energy sources such as solar, wind, geothermal, and biomass. Together with hydroelectric power, these alternative energy sources are also known as renewable or green energy sources (~6%). The big three, crude oil, gas, and coal account for nearly 90% of total energy consumption. These so-called fossil fuels originated from prehistoric life but some scientists maintain a geologic origin from deep in the Earth. If this turns out to be true and we can tap the Earth's interior, there may be no immediate need for alternative fuels. But analysis of crude oil resources indicates that accessible crude oil is limited and could be depleted within a few decades. So, the current reality is that our major source of energy could be gone by the year 2050. Fortunately, this concern and capitalistic ones, have provided an impetus to develop alternative energy sources. Alternative fuels are generally considered to be anything except fossil and nuclear fuels. Of course the usefulness of nuclear fuel for generating electricity is well demonstrated by the presence of over 100 nuclear power plants in the United States (U.S.) and about 200 in Europe. France actually produces ~80% of it's electrical needs from nuclear fuel.
Geothermal
The Earth's interior, aside from being a potential source of crude oil (assuming an abiotic origin), is also a tremendous source of geothermal energy. The temperature of the Earth's inner core which is primarily made up of iron is estimated to be about 5700 degrees K but the iron is not molten because the pressure is estimated to be 3 million times the atmospheric pressure on the surface of the Earth. Thus, the total energy in the Earth's core is staggering, but currently out of reach. Within reach are other geothermal sources called geysers just below the surface that produce hot water. Geysers are about as prevalent as active volcanoes on the Earth's surface. In New Zealand where approximately 40 geysers exist, tapping their thermal power actually reduced the activity of many other local geysers suggesting that the geothermal system is delicate and may not sustain large-scale industrial development. Some of these geysers are now slated for protection in parks like Yellowstone National Park in Wyoming, U.S. where the most geysers (~500) are known. Geysers also occur in Kamchatka, Russia (~200), New Zealand (~40), and Iceland (~16) with ~50 more scattered throughout the rest of the world including California, Arizona, and Utah in the U.S. Relatively large-scale geothermal power plants have been established in California, New Zealand, Iceland, and Kenya. Much less is known about under-sea geysers, but thermal vents on the ocean floor provide excellent geothermal energy sources. Bruce Marshall who patented the first design for the recovery of hydrothermal energy claims that vents compare with nuclear energy for generating electricity. Another geothermal source is the magma and trapped steam near volcanoes. El Salvador, Costa Rica, and the Philippines produce a significant percentage of their total electrical power from such sources.
Biomass
Bioethanol
Biomass has probably received the most attention as an alternative fuel. Beginning with cellulose crops such as corn or switchgrass, enzymes or microbes are used to break down the cellulose into simple sugars that can be fermented into ethyl alcohol and used as an alternative fuel or a fuel additive. It's unlikely that bioethanol will substitute for petroleum because even if all the corn in the world was converted to ethanol, this would still represent a very small percentage of the current petroleum consumption.
Biodiesel
A much more promising alternative fuel is biodiesel. Biodiesel is typically produced from plant oils or animal fats, but algae oil sometimes called oilgae or algaeoleum can be as much as 60% of the algae mass. This high percentage of lipids and their fast generation time, make algae particularly attractive for the production of biodiesel. It was estimated by the U.S. Department of Energy that an algal growth area of only about 15,000 square miles would be sufficient to produce enough algaeoleum to replace petroleum in the U.S. This is an area approximately the size of the states of Maryland and Delaware combined, and represents only about 15% of the total area used to grow corn in the U.S. Many experts believe that growing algae on such a scale is practical because algae can grow in the ocean, fresh water, bioreactors, or even in treated sewage. Even the most conservative estimates for the algal growth area necessary to replace petroleum are in the range of 350,000 square miles or about half the size of the state of Alaska. This is a huge area, but could possibly be farmed in certain ocean regions. Because algae growth areas would not displace existing food crops or reduce natural forests, habitats, and biodiversity, they are considered a friendly feedstock by environmentalists.
Prospects
Currently, it costs about $30 to produce one gallon of jet fuel from algae but researchers hope to be able to reduce this to less than $5/gallon by maximizing algal strains, growth conditions, and production facilities. Most scientists agree that the potential of algal fuels for the replacement of petroleum is very promising and both government and private industry are heavily invested in algal research and development. Recently, the U.S. Department of Defense awarded $35 million to General Atomics and Science Applications International in San Diego, CA to develop algaeoleum jet fuels for military aircraft. The International Air Transport Association has established a goal to supplement their jet fuel with at least 10% alternative fuels by the year 2017. When the “black gold” is gone, we can just fill up our tanks with “green gold.”
Crude oil or black gold is the industrial world's primary energy source and it accounts for approximately 40% of total energy use. With the additional use of coal (~25%), natural gas (~25%), nuclear (~5%), and hydroelectric power (~5%), very little of our total energy use comes from alternative energy sources such as solar, wind, geothermal, and biomass. Together with hydroelectric power, these alternative energy sources are also known as renewable or green energy sources (~6%). The big three, crude oil, gas, and coal account for nearly 90% of total energy consumption. These so-called fossil fuels originated from prehistoric life but some scientists maintain a geologic origin from deep in the Earth. If this turns out to be true and we can tap the Earth's interior, there may be no immediate need for alternative fuels. But analysis of crude oil resources indicates that accessible crude oil is limited and could be depleted within a few decades. So, the current reality is that our major source of energy could be gone by the year 2050. Fortunately, this concern and capitalistic ones, have provided an impetus to develop alternative energy sources. Alternative fuels are generally considered to be anything except fossil and nuclear fuels. Of course the usefulness of nuclear fuel for generating electricity is well demonstrated by the presence of over 100 nuclear power plants in the United States (U.S.) and about 200 in Europe. France actually produces ~80% of it's electrical needs from nuclear fuel.
Geothermal
The Earth's interior, aside from being a potential source of crude oil (assuming an abiotic origin), is also a tremendous source of geothermal energy. The temperature of the Earth's inner core which is primarily made up of iron is estimated to be about 5700 degrees K but the iron is not molten because the pressure is estimated to be 3 million times the atmospheric pressure on the surface of the Earth. Thus, the total energy in the Earth's core is staggering, but currently out of reach. Within reach are other geothermal sources called geysers just below the surface that produce hot water. Geysers are about as prevalent as active volcanoes on the Earth's surface. In New Zealand where approximately 40 geysers exist, tapping their thermal power actually reduced the activity of many other local geysers suggesting that the geothermal system is delicate and may not sustain large-scale industrial development. Some of these geysers are now slated for protection in parks like Yellowstone National Park in Wyoming, U.S. where the most geysers (~500) are known. Geysers also occur in Kamchatka, Russia (~200), New Zealand (~40), and Iceland (~16) with ~50 more scattered throughout the rest of the world including California, Arizona, and Utah in the U.S. Relatively large-scale geothermal power plants have been established in California, New Zealand, Iceland, and Kenya. Much less is known about under-sea geysers, but thermal vents on the ocean floor provide excellent geothermal energy sources. Bruce Marshall who patented the first design for the recovery of hydrothermal energy claims that vents compare with nuclear energy for generating electricity. Another geothermal source is the magma and trapped steam near volcanoes. El Salvador, Costa Rica, and the Philippines produce a significant percentage of their total electrical power from such sources.
Biomass
Bioethanol
Biomass has probably received the most attention as an alternative fuel. Beginning with cellulose crops such as corn or switchgrass, enzymes or microbes are used to break down the cellulose into simple sugars that can be fermented into ethyl alcohol and used as an alternative fuel or a fuel additive. It's unlikely that bioethanol will substitute for petroleum because even if all the corn in the world was converted to ethanol, this would still represent a very small percentage of the current petroleum consumption.
Biodiesel
A much more promising alternative fuel is biodiesel. Biodiesel is typically produced from plant oils or animal fats, but algae oil sometimes called oilgae or algaeoleum can be as much as 60% of the algae mass. This high percentage of lipids and their fast generation time, make algae particularly attractive for the production of biodiesel. It was estimated by the U.S. Department of Energy that an algal growth area of only about 15,000 square miles would be sufficient to produce enough algaeoleum to replace petroleum in the U.S. This is an area approximately the size of the states of Maryland and Delaware combined, and represents only about 15% of the total area used to grow corn in the U.S. Many experts believe that growing algae on such a scale is practical because algae can grow in the ocean, fresh water, bioreactors, or even in treated sewage. Even the most conservative estimates for the algal growth area necessary to replace petroleum are in the range of 350,000 square miles or about half the size of the state of Alaska. This is a huge area, but could possibly be farmed in certain ocean regions. Because algae growth areas would not displace existing food crops or reduce natural forests, habitats, and biodiversity, they are considered a friendly feedstock by environmentalists.
Prospects
Currently, it costs about $30 to produce one gallon of jet fuel from algae but researchers hope to be able to reduce this to less than $5/gallon by maximizing algal strains, growth conditions, and production facilities. Most scientists agree that the potential of algal fuels for the replacement of petroleum is very promising and both government and private industry are heavily invested in algal research and development. Recently, the U.S. Department of Defense awarded $35 million to General Atomics and Science Applications International in San Diego, CA to develop algaeoleum jet fuels for military aircraft. The International Air Transport Association has established a goal to supplement their jet fuel with at least 10% alternative fuels by the year 2017. When the “black gold” is gone, we can just fill up our tanks with “green gold.”