The race to replace fossil fuels with new sources of energy is on. We know about ethanol and we all know the guy in town who powers his diesel car with vegetable oil, but it seems like every time I open a magazine, I find an article about another Messiah of fuel technology that will rescue the environment and deliver us from the evils of dependence on foreign oil. So what are all of these proposals? If they’re so wonderful, why haven’t they been implemented on a large scale? I decided to take a look at the potential alternative fuels, their efficacies, and impacts.
Ladies and gentlemen, I give you pond scum! Until now, you may only have thought of algae as that annoying gunk that builds up in your swimming pool, but these little guys can yield roughly thirty times more energy per acre than corn or soybeans, according to the U.S. Department of Energy. This is because of their simple cellular structure and rapid reproduction rate.
The fact that algae can grow in water under the harshest conditions gives them an added edge over land crops. It would take about half the land mass of the United States to grow enough soybeans to feed the demand for biodiesel, but algae would only require 15,000 square miles (about the size of Maryland) to completely replace all the petroleum fuel in America.
Not only will “oilgae” be a much cleaner alternative for future energy use, it can actually help to reverse some of our past carbon emissions. Algae grow by photosynthesis; they ingest carbon dioxide and emit oxygen as a byproduct. Currently, several power plants across the country are testing algae’s potential as carbon absorbers by directing their emissions directly into enclosed ponds. That way, smokestack emissions feed the organisms and produce new fuel instead of entering the atmosphere.
No large-scale facilities for processing algae into fuel exist yet, but Boeing and Air New Zealand announced a joint project last year to develop an algae-based jet fuel. Virgin Atlantic is also looking into algae processing technology as part of its larger biofuels initiative.
Jatropha: The Little Seed That Could
The seeds of the jatropha tree are almost 40 percent oil, which can be made into a clean-burning diesel fuel. Already, the railway line between Mumbai and Delhi in India runs on 15 to 20 percent biodiesel produced by the jatropha plants cultivated along its route. In December 2008, Air New Zealand successfully flew a Boeing 747 using a fuel blend that was half jatropha and half conventional aviation fuel.
Jatropha is native to Central America and was used by Portuguese traders in the 16th century in fuel lamps. Unlike corn and soy, jatropha would not compete with food crops for arable land. It thrives in tropical and subtropical climates where, even in the worst soils, it grows like a weed.
India has already reserved 100 million acres for jatropha cultivation in the hopes that the fuel will provide 20 percent of its diesel consumption by 2011. Australia, China, Brazil, and Kenya have also embraced the plant for its potential to alleviate the food crisis in their countries by freeing up arable land that is currently used for biodiesel fuel from corn or soy.
The biofuel produced from jatropha seed oil is almost entirely clean burning. Even better, the trees themselves capture four tons of carbon dioxide per acre through photosynthesis, which makes the carbon footprint of this fuel source a negative number from start to finish.
Here Comes the Sun
It’s easy to be pessimistic about the economy these days, but one area that is growing is solar power. Thanks to generous state and power company incentives and rebates, as well as tax credits that make solar systems more widely affordable, the surge in demand for solar power has created thousands of small businesses and new jobs.
The Solar Energy Industries Association (SEIA) estimates that there are approximately 3,400 companies and 30,000 to 40,000 jobs directly related to solar energy within the United States. These jobs could not exist without government subsidies. The Solar Center at North Carolina State University in Raleigh maintains a database that shows more than half the states as having rebate or incentive programs for solar power, a renewable, clean energy source.
An Imperfect Storm
If you’ve ever gone outside on a windy day and almost been knocked on your butt by a strong gust, you know that wind has plenty of power. Some households have already purchased their own wind turbines for electricity; my electricity company, the Long Island Power Authority (LIPA), offers a special program for those who want their power to come from the company’s wind farms.
Wind power does not provide a complete answer to our energy needs, however. A preliminary investigation into wind farming, published in the October 2004 issue of the Journal of Geophysical Research, suggested the possibility of an adverse effect on local weather systems if not properly designed. Other objections to wind farming include aesthetic issues, expense, noise, and fears of danger to wildlife. Much exploration of this technology has yet to be conducted before it is adopted as an alternative to fossil fuels.
Turning the Tide to Energy
Tidal power is big in Britain, where the island nation could reap 20 percent of its energy needs from the huge tidal forces that move tons of water around each day. The technology would only work for other coastal areas that have access to water, but for those that do, it is lucrative. Tidal energy is completely renewable and predictable. Even better, once you’ve built a system for harnessing it, tidal power is almost completely free to obtain and produces no greenhouse gases or other byproducts.
The first attempt to harness tidal power was the development of tidal barrages, huge dams that are built across river estuaries. When the tide goes in and out, the water flows through tunnels in the dam and can be used to turn a turbine.
There are problems however. A tidal barrage has been proposed across the Severn Estuary in Gloucestershire, which carries sewage and other wastes from many places (like Bristol and Gloucester) out to sea. The barrage would slow this process and possibly prevent the outlet of ocean-bound trash.
Another consideration is for the area’s wildlife. More than 80,000 birds feed on the exposed mud flats when the tides go out. The tide barrage would prevent the tide from going out properly, leaving these birds out of food and out of luck. Also, since the tide only goes out twice a day, the power generated by a tidal barrage only provides enough power for about ten hours a day.
A more promising solution is offshore turbines. The tidal “reef” of turbines being proposed for the Severn Estuary is very much like a tidal barrage except that it does not block the water movement as much. Migratory fish could get through, mud flats would still be exposed at low tide, and it would be able to generate power for more hours in the tidal cycle. The turbines are submerged, mitigating visual and noise impacts.
Under the Sea
The ocean provides another fuel source: the methane hydrates trapped beneath marine sediments and in Arctic regions. These occur abundantly in nature and look pretty much like regular ice, except that they are really crystalline solids of gas molecules surrounded by a cage of water molecules. According to the United States Geological Survey (USGS), extraction of methane from hydrates could provide an enormous energy resource and potentially free up fossil fuel resources trapped beneath hydrate layers.
There are many problems with this idea, however. The methane in hydrates would release approximately 3,000 times the volume of methane in to the atmosphere that already exists. It’s important to conduct further research to determine how this potential fuel source could be harvested more safely and with smaller environmental impact.
Geothermal is Hot
The Earth’s core is approximately 10,832º F. Even just a few miles below the surface, earth temperatures are a thermometer-busting 482º F. That is why geothermal heat has been used for thousands of years for heating and cooking; its first human use in North America occurred more than 10,000 years ago with the settlement of Paleo-Indians around hot springs.
Currently, geothermal energy is an important resource in volcanically active places such as Iceland and New Zealand. Drilling into the earth releases steam, which is then purified and used to drive turbines for powering electric generators. The steam can also be passed through a heat exchanger to heat water to warm houses (an entire town in Iceland is heated this way).
Geothermal energy does not produce any pollution or contribute to the greenhouse effect, and the power stations do not take up much room or have any significant environmental impact, although it is possible that hazardous gases and minerals might be released by drilling. Like other natural power sources, once you’ve built a station, harvesting the energy is almost free. The big problem is that there are not many places where you build a geothermal power station, since you need exactly the right type of hot rock and exactly the right depth in order for the process to work. The power itself is also not so dependable, since sites can “run out of steam” for decades at a time.
One Man’s Trash Is Another Man’s Power
Ever since the first cave man discovered fire, humans have burned biomass to provide heat. We have tons of solid mass sitting in landfills, so why not put it to work?
A process called bioconversion uses plant and animal waste to produce methanol, natural gas, and oil. Basically, you burn whatever fuel you’re using—garbage, manure, sugar cane, seaweed, pretty much anything—to heat water and make steam. The steam turns the turbine, the turbine powers the generator, and you’ve got yourself some electricity.
It seems like the ultimate recycling, but burning anything releases carbon dioxide into the atmosphere, contributing to the greenhouse effect. So don’t stop worrying about being wasteful because you figure you can power your television with those discarded Starbucks containers. This one is still in the works.
No Easy Answers
Although each of these has been touted by some as the magic elixir for all of our energy problems, there is still no single replacement for petroleum. None of these can individually provide enough power to supply all of our needs for the way we live now and a combination of approaches will probably work best. We should keep moving forward with research, but we should also think about lifestyle changes to reduce our energy consumption. It may be the only solution.