The next time you look at the unsightly scum on a nearby pond, keep in mind that it - or something very much like it - may someday help you fuel your car and heat your home.
Most people think of oil as a legacy from the days of the dinosaurs - a fossil fuel that took millions of years and tremendous geological pressures to produce. Because of this, oil is seen as a nonrenewable resource: There is a finite amount and when that is gone, there is no more.
But recent scientific advances are showing that these assumptions about oil aren't necessarily so. Biologists are finding that a number of nature's simplest form of plants, blue-green pond algae, for instance, and many other microorganisms make various oily substances under the proper conditions.
These scientists are finding that petroleum-like substances are being made naturally in an amazingly wide range of conditions. Ultimately this knowledge may make it possible to ''grow'' oil economically rather than drilling and pumping it.
For instance, Peter Lonsdale of Scripps Institution of Oceanography has discovered geothermal springs at the bottom of the Gulf of California where ''young petroleum'' is produced. ''Instead of high pressure, low temperatures, and long times, the areas we found are producing a considerable amount of petroleum with high temperatures and low pressures,'' Dr. Lonsdale explains. Rich organic sediments, like those found under productive fisheries, and a source of geothermal energy are the conditions required, the field researcher says.
Then too, oily substances are made by many more complex plants. Several years ago the Nobel-prize winning chemist Melvin Calvin discovered a tree in the Brazilian rain forest that produced an oil so close to diesel fuel that an engine would run on it. Since then he has been working on ways to cultivate plants to produce latex-like hydrocarbons that can be easily processed into an oil-like fuel.
In fact, Tom Tornabene, now at Georgia Institute of Technology, was able to induce a species of bacteria to produce an oil virtually identical to some forms of crude oil simply by controlling its environment. And the Solar Energy Research Institute (SERI) here has a program designed to come up with methods for growing and harvesting oil from algae economically.
''For some time we have known that certain algae produce oil. In fact, it is a very natural process. A major problem has been one of identification. But we have developed an approach using a special dye which makes this much quicker, simpler, and less expensive,'' explains Steven Lien, a SERI senior scientist. In fact, scientists at the institute have found some ''massive'' oil producers right outside their laboratory door, he reports.
Lawrence Raymond coordinates the SERI work in this area. ''Our experiments suggest that it is possible to produce a half to a full barrel of oil per acre per day using algae. This is a (10 times) greater production than you get by growing corn and distilling it into ethanol,'' he says.
Dr. Raymond admits it will be difficult to make oil-growing profitable. To grow these microorganisms at the maximum rate requires concrete raceways, pumps or paddle wheels to keep the water moving, precise control of the environment to force the algae to make large amounts of oil, and methods to harvest the oily microorganisms. In Israel, where some of the most advanced algae culturing work is being done, the cost of constructing these facilities has averaged $18,000 per acre and yearly operating costs have topped $20,000. ''To make oil, we've got to do an awful lot better than that,'' Raymond acknowledges.
Nonetheless, he thinks it can be done. An example is work being done by Ed Laws at the University of Hawaii. He is working with ocean algae. These algae produce oil to give them added buoyancy to keep them near the surface where they get adequate light. By putting blue plastic filters over the shallow ponds where they are being raised, researcher Mr. Laws found that the algae react as if they are too deep and produce large amounts of oil in a vain effort to float nearer an imagined surface.
Harvesting has always been a major problem in algae oil production. But this particular species has a special characteristic. When they reach a high density, they produce chemicals that form a foam. The oiliest of the algae stick to the foam bubbles. As a result, collecting and removing the foam harvests just the right type and amount of algae, says SERI's Dr. Raymond.
Raymond, who admits this is a favorite projects, envisions large algal oil-growing operations in the desert Southwest. Species of algae that grow well in salty groundwater could be raised in large, covered ponds.
To meet total US oil demand in this way would require over 18 million acres of algae ponds. But SERI has identified over 86 million acres that would be suitable. ''Every single microalgal technology originated in the US. All have been commercialized in other countries. Here we have a new technology conceived of here. The big question is, 'Will we develop it?' '' Raymond asks.