Week 6

Introduction:
         One way to reduce the energy usage at station would be a battery bank. The batteries would be charged by the generator and serve as the power source for as long as they lasted. Another  method would utilize a human powered water pump to replace the old gas pump. These two systems would be more efficient and save energy overall.


Battery Storage Component:

        One way to increase efficiency at the station would be to store the excess energy produced by the generator while its running. The generator will typically produce more power than is needed when it is in use. This excess energy is lost to heat, noise or the incomplete combustion of the fuel. A bank of batteries could be used to  store all the power produced by the generator and then used for electricity later on. 

       The system would take the electricity created by the gas generator and initially step it down with a charge regulator. This would produce a voltage above 12 volts but not exceeding 14, the safest maximum before overheating and failure. A voltage below 12 volts would cause a back-flow of electricity so the regulator keeps the voltage in this range. The voltage would charge the batteries in a predictable amount of time dependent on the output of the generator. Once the batteries were fully charged, an invertor would step the voltage up form a 12 volt DC current to 120 volt AC current. Most appliances run on 120 volts so the battery bank could be used to charge laptop, camera and phone batteries as well as running lights and an internet modem. [1]
          Figure 1 shows the energy flow of the battery system, as power moves from the generator, is stepped down by the regulator, stored in the batteries, stepped up by the inverter and used by appliances.

Figure 1: Flow Chart for Battery System

Bicycle Water Pump Component:

           To pump water from the lower reservoir into the higher one the field station currently uses gas generator. The higher reservoir is above all facets and piping which allows gravity to do work and create a water pressure for when being used in the instances of showering or toilet flushing. Figure 2 shows a depiction of how present water pumping system. 

Figure 2: Current Water Pumping System

The bicycle pump will replace the electric pump that utilizes the gas generator for power. This will minimize gas consumption and in turn reduce cost. Further cost analysis will give numerical estimates. The bicycle water pump system works by taking apart an old bike locking it into place, either with bolts or cementing it to the ground. The gear would then attach to pulley system that is created with the removed wheels. A wire with stoppers is latched to the pulley which rotates and traps the water from the lower reservoir into PVC (polyvinyl-chloride) plumbing tubes that dumps into the higher reservoir.

Figure 3: Proposed Water Pump System [2]

Work Cited

[1] "Basic Tutorial: Storage Batteries" Internet: http://www.freesunpower.com/batteries.php, [8 May 2012].

[2] “Working Bikes.” Internet: http://workingbikes.org/node/3445, [8 May 2012].