Self-Sufficient Spring Capillary System For Generating Hydroelectricity

Great Neck South High School, Great Neck, NY





From Left to Right: Robert DeKoff (Teacher-Advisor), Sangita Patel and Ayako Kumei





THE PROBLEM



Energy production has become an increasing global concern. The need for new forms of energy to produce electricity is currently an intense field of research. Almost every part of the world is dependent on electricity, whether it be for running the appliances of daily living or powering intricate computers.

As a highly developed nation, the United States is a top energy consumer. Aside from major industrial use of electricity, the average household uses about 18 kilowatt hours per day. Most of this electricity comes from the burning of fossil fuels.

The main concern about producing electricity using fossil fuels is the negative impact on the environment and the depletion of a nonrenewable natural resource. Global problems caused by the end-products of burning fossil fuels include acid rain, air pollution and the greenhouse effect. Some of the major air pollutants are carbon monoxide, sulfur dioxide, and oxides of nitrogen. These pollutants produced in large quantities in large cities rise as smog into the atmosphere which then spreads to other locations, thus affecting the entire Earth. Fossil fuels are being used faster than they are being replaced. Extrapolating on their current rate of use, the supply of fossil fuels might be depleted in about one century unless an alternative source of energy is found.

New energy sources are being sought. The United States is researching and currently using electricity produced by nuclear fission, moving water, wind, tides, geothermal vents, biomass, the sun, and photovoltaic cells. If this energy shortfall is not dealt with successfully, the pollutants released by fossil fuels will have detrimental effects. With the imminent depletion of the current resources, the United States must find an alternative energy source or risk her status on the planet.



OUR SOLUTION



The best way to produce electricity would be to use the least amount of energy and to have the least amount of waste produced. With this in mind, we designed a self-contained, hydraulic system utilizing the energy in a spring and the concept of capillarity.







THEORY



Hydroelectricity is produced by water falling from a certain height and turning a turbine. Transporting water to this height requires energy. Water can be drawn up to this height using the energy stored in a spring and capillarity can be used to continue the cycle (See Figure One).

When the piston pushes down upon the springs, the amount that the volume decreases on the top is equal to the amount that the volume increases on the bottom. Air travels through the large diameter tubes. The volume increases on the bottom by pushing the movable wall against the lower springs. The springs on the top and those on the bottom will both want to return to their equilibrium positions. Since the piston on the top is airtight, as the springs return to their equilibrium positions, the piston will be pushed up. As the volume increases on the top, the water will be drawn up the tubes because of the pressure gradient created. The rise of the water would also be aided by the springs on the bottom returning to their equilibrium positions and thereby decreasing the volume on the bottom.

There would be openings on the bottom of the pan collecting the water at the top of the tubes (the upper inner pan). Valves would control these openings. The valves would open to release the water when filled in the pan and would close for the functioning of the piston. Check valves would probably serve this purpose. When the valves open, the water would collect in another outer pan (the upper outer pan).

Capillary tubes with their bases in the upper outer pan would surround the perimeter of the inner pan. These capillary tubes would be long enough to reach the top of the piston. Water would be drawn up the capillary tubes and would be directed onto the top of the piston. The weight of the water would then compress the springs and the cycle would begin again.

At some point when the water is on the piston not in its equilibrium position and the volume change in the system is sufficient, another valve would open allowing the water to be released into a holding tank. The water would collect in this holding tank and would empty periodically by means of a float valve. This would then be used to turn a turbine which would be connected to a generator to produce electricity. After turning the turbine, the water would return to the lower pan at the bottom of the tubes. A check valve would regulate the entry of the water so that it would not interfere with the functioning of the piston.

The turbine could be one of two types. One type, a high-tech turbine, would turn at very high speeds. The high speeds would be achieved by employing a device, something like a funnel, that would convert the pressure of a volume of water into force. This would directly operate a generator. Another type of turbine would work by a great volume of water creating torque. Its movement would be converted by a gearbox which in turn would operate a generator.



EXPERIMENTS &

DEMONSTRATIONS



We demonstrated the concept of the piston-spring system. It would take approximately 18 cycles of one piston to collect one liter of water. If a few of these systems were set up near each other and they all emptied into one holding tank, the water would collect in the tank at a faster rate.

Our design, when slightly modified, can also be used to generate electricity with exercise bicycles. If the capillary tubes and the upper outer pan were removed, an arm was attached with the piston and the wheel of the bicycle, and the valves of the upper inner pan were connected directly to a tube leading to the turbine, then the water drawn up the tubes could be used for generating electricity directly without the time delay waiting for the capillary tubes to transport the water to the top of the piston. If the original system was made such that these parts could be easily removed and attached, our design would be even more useful because it would generate electricity on its own and also while someone exercised - good for the human and good for the environment.









CONCLUSION & DISCUSSION



This is a clean, workable method of producing electricity. A major point is that there are no harmful waste products.

The only time we would have to provide energy for this system is to start it for the first time and when the frictional forces slow it down too much. Since there is no water on the top of the piston when the system is started, an outside force would have to be used to push the piston down the first time. Because of the frictional forces of the moving piston, the cycle would eventually slow down. A force would also have to be applied then. If the system was frictionless, this force would not be necessary.

Since the capillary tubes do not require energy in transporting the water onto the piston to continue the cycle, if the system was completely frictionless, it might, in theory, be an example of perpetual motion. This is what makes our solution superior to other solutions now being tried. The other solutions, such as solar power, require energy input from the sun; wind power requires energy input from moving air masses. Our solution contains all the energy needed within itself. But because there is loss to friction in our system, it cannot be considered perpetual motion. Even though it is not perpetual motion in reality, it is still better than other solutions because it requires the least amount of energy input to continue its motion.

This hydraulic system would work well for small scale application in a household and also for large scale electricity production in a country. Although it would not be able to meet all the energy needs of a country, it would be able to provide a small portion of it. If this is used in conjunction with solar power, wind power, and other "clean" sources of electricity, the United States might be able to relieve some of its dependence on fossil fuels.

This is just one solution to this world's energy crisis. If the United States is going to face this problem head on, all possible safe solutions must be researched, experimented, and tried in some form. The answer to this problem may not all be in one solution.