To: Aimee McClure, John Krueger From: Karl Vachuska, Shiven Advani, Pilar Gonzalez, Valerie Nehls Subject: Hydroelectric Generator Recommendation

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1 To: Aimee McClure, John Krueger From: Karl Vachuska, Shiven Advani, Pilar Gonzalez, Valerie Nehls Subject: Hydroelectric Generator Recommendation Date: 12/5/2016 Our group worked with Pierce Manufacturing on a project that would lead Pierce to becoming more sustainable, while simultaneously being more cost efficient. Below, we provide a series of recommendations to assist Pierce Manufacturing with this task. We spent time with representatives of Pierce and gained insight into the pump testing process and water usage of Pierce Manufacturing s operations. Based on our work with Pierce, our most significant recommendation would be to install a hydroelectric generator at the end of the peto tube. This process would take advantage of the potential energy generated by the force of the water being pumped. This potential energy would be converted to kinetic energy by passing through a turbine. This energy, with the use of a hydroelectric generator, would result in the production of electricity. This generation of power would help to reclaim energy lost in the pump testing process and produce electricity for the water testing facility. Not only will this lead to Pierce Manufacturing being a more sustainable firm, but also, it will save a great deal of money for the firm. Energy consumption is huge and represents one of the largest costs modern day businesses and production facilities face. In order to minimize significant expenditures and overall risk, we will go into detail about our recommendations and the costs and benefits of installing a turbine coupled with a hydroelectric generator to the pump testing facility at Pierce Manufacturing.

2 Figure 1: Water flow process of the pump testing facility In figure 1, the water flow process to test the pumps used at Pierce Manufacturing is outlined. Water is drawn from a 80,000 gallon pit into the fire truck hose. The testing facility has one 80,000 gallon and two 40,000 gallon pits. This water is then pumped out of the truck s hose for a continuous six-hour period on the test stand in order to confirm the quality and integrity of the hose pumping system in each truck produced. The water then flows out of the truck s hose and up towards the ceiling through a pipe. The water comes down and through a peto tube on the ground. A peto tube is a pressure measurement instrument used to measure fluid flow velocity. From the peto tube, the water is recycled back into the pit. Flow rates vary from gallons/min, volume varies from m 3 /s, and pressure varies from psi. Given the set up of the water flow process, we are recommending a hydroelectric generator to be installed in the water flow process to take advantage of potential energy generated from the pumping system. This accessory to the system will serve to generate electricity and power for the testing site significantly reducing electricity costs. Proposal: In order to utilize the potential energy available in the water testing system, we recommend a Pelton hydroelectric turbine and generator accessory to be installed directly underneath the exit of the peto tube. We recommended a Pelton turbine in particular, due to the high level of head present in the water testing system. The Pelton turbine is one of a few turbines able to handle such pressure. Some other options, besides the Pelton turbine, that we considered would be a turgo or a banki turbine, all of which are types of impulse turbines. Impulse turbines work off the kinetic energy of moving water to spin the shaft that is attached to the generator. Water directly falls on

3 the turbine and these types of turbines could reach efficiencies of up to 90%. The turgo turbine is built to handle larger flow rates and has a more complex blade design, but has a lower efficiency rate than the Pelton turbine, which typically has an efficiency of around 85%. The banki turbine has an even lower efficiency than the turgo, but utilizes a simpler design. Based on efficiency and the specifications provided by Pierce Manufacturing, we determined that the Pelton turbine would be the best fit for Peirce Manufacturing s case. Figure 2: Schematic of a Pelton Turbine Figure two shows the general setup for a Pelton turbine. The stream of water exiting the peto tube would hit the buckets of the turbine, causing the inner shaft to spin. The Pelton turbine utilizes the high velocity water flow to turn, as opposed to the dead weight of water used in traditional overshot water wheel. Also, the Pelton s paddle geometry is designed so that when the rim runs at half the speed of the water jet, the water left in the wheel would have very little speed. Thus design allows for the Pelton turbine to extract almost all of the water s impulse energy, which in turn, allows for very high efficiency. Savings: For calculating savings, we performed two calculations. One calculating the low-end cost estimate and the other calculating high-end estimates. This allows us to produce a range with a high degree of certainty. Low end savings estimate:

4 The equation for calculating power of a hydroelectric generator involves four variables; density, water flow, gravity and head. P th = ρ q g h where P th = power theoretically available (W) ρ = density (kg/m 3 ) (~ 1000 kg/m 3 for water) q = water flow (m 3 /s) g = acceleration of gravity (9.81 m/s 2 ) h = falling height, head (m) Between the temperatures of 32 degrees and 100 degrees Fahrenheit, the density of water varies only minimally, between 993 and 1000 kg/m 3. For the purposes of calculations we will use an average estimate of 997 kg/m 3. The low end water flow estimate is 1250 gallons per minute, or m 3 /s. Gravity remains 9.81 m/s 2 Technically there is no head to the water system, since the water is pumped in a continuous loop without being held at a major point. However, a variable head-equivalent can be calculated given the pressure of the water as it exists the peto tube (the point in which the turbine would be installed). The equation for the relation between head and pressure is: psi=(head*specific gravity of liquid)/ or equivalently: head=(psi* )/(specific gravity of liquid) Specific gravity of water is equivalent to density with a magnitude of one onethousandth, so as we used 997 as an estimate of density, we will use as our constant of specific gravity of a liquid. Psi is between 100 and 150 so for purposes of a low end estimate, we will use 100. Now we have, head=(100* )/(0.997)= So we conclude our head to be meters.

5 Now back to our original equation, P th = 997*.078*9.81* = 53, watts However, this is strictly power theoretically available, and so for an accurate calculate we must multiply the standard hydroelectric efficiency coefficient of 0.9 P th = 53, *0.9 = 48, watts. So our final number for the theoretical watt outage of the hydroelectric generator is 48, watts or kilowatts. In order to convert this number into electricity savings over the course of a year, we simply multiply by the number of hours of usage the turbine will experience over the course of a year. Hours = (3 hours at a time)*(2 times a day)*(5 days a week)*(52 weeks in a year) = 1,560 hours a year Kilowatt hours per year = ( kilowatts)*(1,560 hours a year) = 75, kilowatthours The total kilowatt hours produced each year at a low end estimate is 75, Since Pierce is charged for electricity at a rate of approximately 8 cents per kilowatt hour, I can conclude a low end estimate for value of electricity produced yearly through installation of a hydroelectric turbine, and subsequently money saved to be $6, High end estimate A high end estimate can easily be derived by substituting in high end estimates for variables that had a range. Those variables are as follows: Instead of using m 3 /s for water flow, substitute m 3 /s. Instead of using 100 psi, substitute 150 psi. And finally, instead of using 3 hours a day, substitute 4 hours a day. Now, aggregating our equations together and substituting in the high end variables, we can create a high end estimate for the value of energy produced. Value = ((997*.189*9.81*(150* )/(.997)))*0.9*(4*2*5*52)*.08)/1000 = $29, Between an extreme low end and an extreme high end estimate, we can safely conclude the yearly savings as a result of reduced energy costs from usage of a hydroelectric generator in the water testing system to be between $6, and $29, yearly. Costs:

6 After consulting with a company that produces hydroelectric generators, an estimated cost, including installation, of a hydroelectric turbine meeting these specifications is between $100,000 and $150,000. Relating back to yearly savings derived as a result of usage of the hydroelectric generator, the cost of investment will be made up in between 4 and 18 years, with an average expectation of 7 years. We had a chance to talk with some of Pierce Manufacturing s competitors to see what other fire truck manufacturers were doing to save energy during the pump testing process. Rosenbaurer South Dakota, LLC utilized the heat generated from the friction of the pumping process. They send this energy in the form of heat to a heat exchanger in order to provide heating for their facilities. This is a viable alternative for Peirce Manufacturing, but they would have to consider if it would provide enough energy to be able to heat their facilities, being in a colder climate. Hydropower is one of the oldest methods of electricity production with the world s first hydroelectric power station began to generate electricity in 1882 in Appleton. Despite hydropower s long history, it does not cover a significant portion of the US s electricity production today. Hydroelectric power currently only represents about 9.8% of all energy production in the United States. Hydroelectric power however has much more significant potential as an energy source. For example, the country of Norway currently produces more than 99% of its energy from hydroelectric power sources. Hydroelectric power offers a variety of advantages over other energy systems. Hydroelectric power: 1) is one of the cheapest ways to produce electricity; 2) is one of the most efficient ways to produce electricity; and 3) is one of the cleanest ways of producing electricity. Hydroelectric power is an appropriate choice as a method of harnessing energy given its low cost, efficiency and cleanliness. Hydroelectric generators are an excellent way to generate energy and save energy costs. Hydroelectric power systems are capable of harnessing up to 90% of available energy, which is a huge percentage, incomparably greater to other methods of electricity generation. If Pierce Manufacturing decides to install a turbine coupled with a hydroelectric generator, they will see a return on investment in a relatively short amount of time, continue to save energy costs, and they will make their company more sustainable in the process.