The burning of fossil fuels is the main cause of acid rain. Many people have already started doing this and have found a source of pre-biofuel. They buy converters for their diesel engines for about one thousand dollars, and run it off of used grease from restaurants. This serves as a benefit for both the customer, and the restaurant owner, in that the customer gets free biofuel, while the restaurant owner gets free disposal of the grease. Many restaurants pay annually for this service, and continue to pay it through the years. Now, with the future of petroleum engines, the restaurants won't have to pay for this service. They now may be able to charge for it if the demand gets to a high enough level, which does not seem unfeasible if a city of sixteen thousand is looking for the fuel when their city only has thirty restaurants. This method seems perfect, but there is a major flaw. When burning biofuel instead of petroleum, the driving distances are greatly reduced (De Romana). Dams are another major source of power. The Hoover Dam is a big source of energy for surrounding areas. Hydroelectric power is produced by very large turbines, which are spun by the immense water pressure leaving the blockaded portion of the river. This invention is ingenious, in that the rivers are a virtually never-ending source. These dams also produce another complaint by animal rights activists, because migratory fish are unable to swim up-river. This causes many deaths in