Alternative Energy Replacements for Crude Oil

Which Green Renewable Energy Sources Could Replace Oil?

Oct 23, 2009

Alternative energy is anything but fossil and nuclear fuel. Which source can most likely replace crude oil on its own: hydroelectric, solar, wind, geothermal, or biomass?

Crude oil or black gold is the industrial world's primary energy source and has been estimated to account for anywhere from 30-40% of total energy use. With the additional use of coal, natural gas, nuclear, and hydroelectric power, alternative energy sources such as solar, wind, geothermal, and biomass account for very little of the total. In fact, a 2006 British Petroleum (BP) study indicates that hydroelectric power and the alternative energy sources (collectively also known as renewable or green energy sources) account for only about 7% of total worldwide energy consumption. Wind and Solar power currently make the smallest contributions but they will continue to grow and supply significant electrical power in local areas.

The big three: crude oil, gas, and coal account for over 75% of total energy consumption. These fossil fuels originated from prehistoric life on Earth. 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 the 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 U.S. and about 200 in Europe. Japan and France generate approximately 30 and 80%, respectively, of their electrical power from nuclear fuel.

Geothermal Energy Alternatives

Geysers are about as prevalent as active volcanoes but the 1000 or so geysers scattered across the world are not capable of replacing oil. However, large-scale geothermal power plants based on geysers exist in California, New Zealand, Iceland, and Kenya.

Hydrothermal vents in the ocean floor provide excellent geothermal energy sources. Bruce Marshall who patented the first design for energy recovery from hydrothermal vents stated in a comment to a post on the website CleanTechnica.com that "Hydrothermal vents are nature’s closest approximation to a nuclear reaction."

Another promising 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 Energy Alternatives

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 use.

A much more promising alternative fuel is biodiesel which is typically produced from plant oils or animal fats. However, algae may also be a source of biodiesel in the future. 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 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 the oceans or multiple land areas. Importantly, because algae growth areas would not displace existing food crops or reduce natural habitats and biodiversity, algae is considered a very favorable feedstock by environmentalists.

Prospects for Algaeoleum to Replace Crude Oil

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 per 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. Exxon Mobile Corporation, the most profitable company in the world, is investing $600 million in algae research. 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, and the U.S. Navy has set a goal to make renewable energy sources 50% of their total energy consumption by 2020.

References

REN21. 2006. “Renewables Global Status Report 2006 Update” (Paris: REN21 Secretariat and Washington, DC:Worldwatch Institute). http://www.ren21.net/globalstatusreport/download/RE_GSR_2006_Update.pdf

Michael Briggs, "Widescale Biodiesel Production from Algae", University of New Hampshire, 2004. http://www.unh.edu/p2/biodiesel/article_alge.html

Susan Kraemer, "Mining Hydrothermal Vents For Renewable Electricity, Drinking Water + Valuable Minerals", CleanTechnica.com, September 4, 2009, and comments by Bruce Marshall in response.

"Microalgal Production", SARDI Aquatic Sciences, Government of South Australia, 2008. http://www.pir.sa.gov.au/__data/assets/pdf_file/0006/77055/microalgal_prod.pdf

The copyright of the article Alternative Energy Replacements for Crude Oil in Energy Conservation is owned by Don Kaiser. Permission to republish Alternative Energy Replacements for Crude Oil in print or online must be granted by the author in writing.