Exciting Alternative Energy Sources Right Under Our Noses

By James Donahue

The April edition of Common Ground offers an interesting article by Alastair Bland that outlines four “far-out renewable energy technologies” that are not only feasible, but already in the works to be future sources of heat, lights and power.

Reaching beyond the most common sources including wind, solar, ocean currents, flowing rivers and making ethanol from plants, Bland takes his readers into new and somewhat thought-provoking places. They include methane gas from sewage plants, and livestock feedlots; gasification of landfill trash, converting algae into oil and capturing hydrogen from thin air.

Among the most exciting concepts revealed by the article is converting algae into biofuel. It seems that algae cells form, mature and divide within hours, thus making it an extremely fast-growing life form that lives on the carbon dioxide and hydrogen that exists in the air. Its presence helps clean the air of carbon dioxide.

Even more exciting is that a single acre of land converted to ponds for algae production can produce from 5,000 to 10,000 gallons of oil each year. By comparison that acre used for soybean production would only produce from 50 to 100 gallons of biofuel. It is estimated that less than 10 percent of America’s cropland would be needed to grow enough algae to supply liquid fuel needs for the entire nation.

It seems that those tiny one-celled organisms can consist of 50 percent vegetable oil. This oil can be processed for either diesel or jet fuel.

The snag in fuel from algae is the high production cost. But some 30 companies in the world are working on this problem. Researchers say algae biofuel may be on the market within the next two years.

The concept of using methane gas for fuel has already been tried successfully on some large cattle farms, and researchers are looking into ways to capture methane, a natural by-product of human and animal waste, from all the right places. Not only are they targeting livestock farms, but metropolitan landfills.

The capture of methane will not only provide a natural fuel source, but it will help ease the problem of global warming, since all of this untapped methane is presently spewing out into the atmosphere and contributing to the heating of our planet.

Researchers say raw sewage can be pumped through sealed chambers called anaerobic digesters. Inside these digesters, particular microbes consume the material and convert it to methane at an estimated rate of six cubic feet of gas per pound of dry material. Thus a 3,000 head dairy farm can produce enough energy to keep 60 average sized three-bedroom homes powered for a year.

Yet another bane on our landscape has been the garbage and trash dumps, or landfills as they are known today. This amounts to millions of tons of unwanted municipal solid waste, and because we are a throw-away society, and insist on wrapping everything we buy in plastic and/or paper, the piles are getting bigger with each passing year. But there is energy in them thar landfills and the technology to capture it is also just around the corner.

The solution to the landfill mess has been tried by some major cities in large burners, but they proved costly to operate and required a lot of refuse before they could be used effectively. Yet this process can be intensified, with the burners operating at a temperature on par with the sun’s surface. Heat like that breaks up the material’s molecular structure, converting it into pure hydrogen and carbon monoxide, which can be converted into synthetic gas that is a building block for a variety of liquid fuels.

This process, called gasification, burns everything so completely there are no waste emissions. All of the energy is converted into hydrogen and carbon monoxide.

While there are still some bugs to be worked out in the gasification process, Japan fired up the first successful plant like this in 2002 and it is processing over 200 tons of solid waste daily. An even larger gasification plant is planned for St. Lucie County, Florida, which is expected to be operating by 2010.

The final idea . . . making fuel from the natural gas that exists in the air . . . is technically possible but so far impractical because of the high cost of doing it. The process is complex and involve specialized electrochemical processing cells that use heat, cooling towers, and a lot of technical tricks that separate hydrogen from oxygen.

The process demands great volumes of air and extreme heat, making it somewhat impractical. Yet technicians are working on this problem, and may someday have a solution.