you wish to service from this well. 2010. Pumps are classified as either positive-displacement or kinetic/centrifugal, and each has advantages. WlU endstream endobj startxref Many producers are used to thinking of pumping lots of water in a short time frame with large-capacity pumps. To determine friction losses in pipe, you should enter (in the Total Dynamic Head tab of the spreadsheet) the type of pipe (PVC, steel, etc. Solar pumps are low volume, pumping an average of 1 to 5 gallons per minute (gpm). Increases of 50 pounds/head in weaning weight have been reported when water in sufficient quantity and quality is provided. Even though wind has been in use for decades and will continue to provide effective solutions for water pumping, solar power has made significant steps toward becoming the system of choice for these situations.

<> Available from https://www.nrel.gov/docs/fy03osti/30361.pdf. endobj This is the power that de-rated 14 PV modules must supply to operate the pump. PV-powered pump systems often discharge to a storage tank to provide the daily water requirement even under lowlight conditions. Q is the flow rate in gpm, D is the nominal inside diameter of the pipe in inches, and L is the total length in feet of the pipe for the system.

Water needs closely correspond to quantity of feed or forage intake; as intake increases, the water requirement level will increase. %%EOF A good match between the pump, PV array, and system parameters is necessary to achieve efficient operation (Morris et al., 2002). For domestic use in a cloudy climate, 10 days may be necessary, while in sunny climates such as New Mexico, 3 days of storage for livestock watering may be sufficient. A companion publication, Circular 671, Designing Solar Water Pumping Systems for Livestock: User Manual (https://pubs.nmsu.edu/_circulars/CR671.pdf), covers the step-by-step instructions for using the Excel spreadsheet to design a solar water pump system. Most PV applications will be pumping at low flow rates (15 gpm), and these low flow rates will not have sufficient water velocity through a large pipe to keep suspended solids from settling out into the bottom of the piping. Masters, G.M. By providing storage, a producer can still provide their daily water requirements from the storage tank at night or on cloudy days. <> systems Variable water delivery depending on sun intensity, Higher initial costs (although costs are trending lower), Acceptable capital costs and low recurring costs, Reliable warranty of 20+ years for panels, System is modular and may be modified to fit needs. The list of available pumps (and manufacturers) is very extensive, and many will be capable of pumping from a surface source or a well. <> While cows may wade out to obtain better water, calves tend to only drink from the shore. The grand total of the entire system (not including the well, labor, storage, etc.) 16 0 obj Calves require higher-quality water and will not fight cows or mud to obtain it. The pump/motor combination (hereafter referred to as the pump) moves water from the source through a pipe to a discharge point, commonly a storage tank that feeds a trough-drinker (Figure 3). 2002. 3. Locating modules close to the water source also helps minimize power losses and costs. 6 0 obj endobj The piping is 0.75-in. A Microsoft Excel spreadsheet to provide an easy and visual educational tool to present concepts behind PV technology and system design methodology (available to download at https://pubs.nmsu.edu/_circulars/CR671/CR671.xlsm ). 7Average pump efficiencies are in the 2535% range. A multiplier may be added that can provide an extra water cushion, offset evaporation losses, or refill the storage tank. In addition, these factors should be considered: Who will install and maintain the system. For surface sources, a well-vegetated riparian zone establishes a buffer that filters and purifies water as it moves across the zone, reducing sediment loads, supporting soil stability, improving water quality, and enhancing wildlife habitat. <>/ExtGState<>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> It is recommended to use winter values since winter has the least amount of sunlight per day and it is best to design for the worst-case scenario. Renewable and efficient electric power systems. Total dynamic head (TDH) is the total equivalent vertical distance that the pump must move the water, or the pressure the pump must overcome to move the water to a certain height. A majority of pumps are positive displacement pumps (centrifugal-type pumps are also common), which enables them to maintain their lift capacity all through the solar day at varying speeds that result from changing light conditions 8. Equation 9 illustrates this, while Equation 10 describes how the PV strings may be connected in parallel to increase total current and thus total power to match or exceed the required pumps power (also determined earlier). endobj A module rated at 50 W may have an operating voltage up to 17.4 volts (V) and a maximum current of 3.11 amps (A). 10 0 obj Oxford: Oxford University Press. In windy, hot, dry areas, you should also take into account evaporation losses associated with open storage methods. <>/Metadata 656 0 R/ViewerPreferences 657 0 R>> Table 3 shows a partial listing of some values used to calculate friction loss due to a fitting. <> In Las Cruces, the latitude angle would be 32 tilt, a summer tilt of 17, and a winter tilt of 47. <> Pumps move water from wells or surface sources. Buschermohle, M., and R. Burns. Because of a variety of benefits, and increased regulations in some states, it is often desirable to move water from a surface source to a different location, elevation, or drinker, or to pump water from a remotely located well. The amount of available sunlight is predictable by location, but there are always variations in weather (e.g., cloudy days 5). <> For the sake of organization and ease of use, the spreadsheet follows the design approach outlined in this publication. Losses due to fittings may be significant. Federal and state tax incentives may lower the initial costs by up to 40% (as of 2012). 23 0 obj Available from https://www.clemson.edu/sustainableag/IP217_solar_livestock_watering.pdf. DC pumps use one-third to one-half the energy of AC pumps and are specifically designed to use solar power efficiently even during low-light conditions at reduced voltages without stalling or overheating. For pumping water from underground aquifers via wells, access to existing AC electric connections (closer than one-half kilometer or 0.3 mi) is again the best option. Head is important to determine how hard the pump must work to move water from the source to a discharge point (i.e., to overcome the equivalent pressure of that water). n.d. Solar-powered livestock watering systems [Online]. 13Draw-down is the level of water that may drop in the well as pumping occursthe well pipe is refilled at a recharge rate. 6@>/at 0*5,Zy94~AIF 11 0 obj <> Two portable demonstration devices that illustrate the concepts and major system components for a solar pumping system. One-half- to two-inch piping is typically sufficient for most scenarios; smaller is cheaper and often more efficient. A companion publication, Circular 671, Designing Solar Water Pumping Systems for Livestock: User Manual (https://pubs.nmsu.edu/_circulars/CR671.pdf), provides step-by-step instructions for using a Microsoft Excel spreadsheet to perform necessary calculations for designing a solar pumping system. 43 0 obj <> endobj In designing an efficient system, one should minimize the amount of work required of the pump, which minimizes the amount of energy needed to operate the pump and thus the size and cost of components. 17 0 obj 9PV mounts may be fixed racks or poles, or some type of tracking system that follows the sun. The first calculation performed is to determine the number of PV modules in seriesa string. Renewable energy for water pumping applications in rural villages [Online; NREL/SR-500-30361]. In selecting a pump, the following parameters should be considered: Once each parameter is clearly addressed, a pump can be selected. 12 All areas of New Mexico meet this limit with values well above 5 kWh/m2 per day. 2004. 8 0 obj Bartlett, B. n.d. Watering systems for grazing livestock [Online]. ",#(7),01444'9=82. Using the spreadsheet allows you to test various design scenarios and demonstrate the design method and terminology for a direct-coupled solar water pumping system. Excessive livestock pressure on surface sources often causes nutrient loading, streamside vegetation damage, erosion, pollution, and decreased animal growth and health. endobj is calculated by adding up all the itemized totals. Sunlight will provide the energy, via the PV modules, to run the pump, and sunlight value is determined by the nearest latitudinal coordinate of the well location (between 31 and 37 in New Mexico). n.d. Disclaimer: This document is intended for educational purposes only in providing a basic understanding of terminology and concepts of design. Household water use demand is variable and depends on climate, usages, and other factors, but is typically around 75 gallons/person/day for drinking, cooking, and bathing. Photovoltaic power systems and the National Electrical Code: Suggested practices [SAND87-0804]. endstream endobj 44 0 obj <>>> endobj 45 0 obj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text]/Shading<>/XObject<>>>/Rotate 0/TrimBox[0.0 0.0 595.276 841.89]/Type/Page>> endobj 46 0 obj <>stream 10See your NMSU county Extension agent for more information. 5 0 obj 25 0 obj JFIF ` ` ZExif MM * J Q Q Q C Using these two key values, you must manually choose a specific pump (from an initial limited selection) that will be capable of pumping water at the necessary Q and TDH. <>/Encoding<>/ToUnicode 46 0 R/FontMatrix[0.001 0 0 0.001 0 0]/Subtype/Type3/Widths[500 500 500 500 500]/LastChar 53/FontBBox[16 -14 462 676]/Type/Font>> % Wiles, J. Circular 670 Thomas Jenkins College of Agricultural, Consumer and Environmental Sciences and College of Engineering, New Mexico State University. endobj The value generated is in units of feet of head (Mott, 2006). It is important to analyze the system properly in order to make it as efficient and economical as possible while still meeting the watering requirements. 2003. Each PV module has an operating output current and voltage. 4Batteries are expensive, must be replaced every few years, and require periodic maintenance, while the useful life of storage tanks may be decades. Box 30001 | Las Cruces, NM 88003-8001, 2022 New Mexico State University - Board of Regents, College of Agricultural, Consumer, and Environmental Sciences, https://pubs.nmsu.edu/_circulars/CR671.pdf, https://www.youtube.com/playlist?list=PL89870B418A514D27, https://pubs.nmsu.edu/_circulars/CR671/CR671.xlsm, https://pubs.nmsu.edu/_circulars/CR671/CR671.xlsx, https://utextension.tennessee.edu/publications/documents/pb1640.pdf, https://www.nrel.gov/docs/fy03osti/30361.pdf, https://www.clemson.edu/sustainableag/IP217_solar_livestock_watering.pdf, https://www.nrel.gov/docs/gen/fy97/21732.pdf, Only works when wind conditions are adequate, Some operating costs and higher repair/maintenance costs, Proven technology with pool of expertise and experience, Difficult to find parts and special tools needed, Proven technology with large pool of expertise, Required periodic maintenance and replacement, Designing Solar Water Pumping Systems for Livestock. endobj Static head is a major part of TDH and refers to the total vertical lift (distance) from the water level in the well to the discharge level. x+*@02,L-T5300700THMLO5PpW M Modules can be wired in series to increase output voltages and in parallel to increase current while also increasing total power. When you insert this value, the spreadsheet determines the solar insolation for winter, summer, or a yearly average. 4 0 obj 2. However, there are reasons to NOT set the pump too close to the bottom of the well: 1. He previously worked for many years in both private and public sectors as a computer scientist and engineer. <> <> These losses depend on the type of pipe (its roughness), total length of pipe including any horizontal runs, flow rate (speed) of the water in the pipe, fittings and joints, and pipe diameter.

Common values of required gallons per day per animal in New Mexico can be found in the Daily Water Requirement spreadsheet tab or in Table 2, but you have the option to change these default values depending on your unique situation 10. %PDF-1.7 Excess power produced by solar panels can be used for cathode protection, to aerate a dugout, or to power an electric fence. <> endobj Available sunlight, which depends on location. The equivalent head pipe friction loss values are calculated for each specific fitting used. When producers do not have economical access to grid electric power 3, they generally look to options such as ram, sling, diesel, wind (Figure 1), or solar powered pumps. Pipe is assumed to be PVC and the price is calculated by dividing the total length of needed pipe by 10 (PVC pipe is typically sold in 10-ft lengths) and multiplying by its market price. Static head is composed of the water depth in the well at its lowest seasonal and draw-down levels plus the elevation from the water surface to the discharge point 13. Solution: From Table 3, the three 90 elbows add the equivalent of 5.625 ft of pipe, the check valve 8.4375 ft, and the gate valve 0.56 ft, giving a total equivalent pipe length head of 14.6 ft (rounded to the nearest hundredth) due to fittings losses. 2It has been shown that livestock will only travel a limited distance to water sources with typical water source spacing of one source per 250 ha to harvest grasslands, otherwise there is strong potential for overgrazing close to water supplies. For permission to use publications for other purposes, contact pubs@nmsu.edu or the authors listed on the publication. 1An excellent source on windmills: https://aces.nmsu.edu/ces/windmill. A deep setting will increase cost, length, and weight of pipe and cable. Requirements for high volumes or flow rates may limit applications. 3It can cost $10,000 to $30,000 per mile to install electrical power line through rugged terrain. Once the daily water requirement is calculated, the solar resourceinsolation, or total sunlight reaching a specific locationis determined. What is the TDH in a well with water depth of 150 ft (no draw-down) and flow rate of 4 gpm? In order to design and successfully implement solar water pumping systems, you need an understanding of several concepts as well as information specific to how you will use your system. Some users are even powering broken windmill pump jacks with portable photovoltaic (PV) systems. endobj Well characteristics, such as water depth, draw-down levels and recharge rates, seasonal variations, discharge elevation from earths surface to water discharge point, total feet of pipe, nominal diameter of the pipe, valves, and elbows, etc. Foster, R., M. Ghassemi, and A. Cota. A controller that allows the pump to start and operate under weak-sunlight periods (cloudy conditions, early morning, late afternoon). The market price for the UF wire is for 250-ft rolls. Costscapital, operation and maintenance, labor, life-cycle, etc. The current is typically in the 3 to 5 A range, which equates to a rough operating power up to (though typically much less) around 1 horsepower (or 746 W). endobj Upper Saddle River, NJ: Pearson Prentice Hall. 2006. Albuquerque, NM: Sandia National Laboratories. ), Figure 4. <> Water level sensor for on/off operation if using storage. In the Pump Selection tab of the spreadsheet, you are shown the calculated Q and TDH. <>

iJbj+1w;~Z+ex~}a{j7qMj\? Modules are sized as DC power (watts [W]) and come in all sizes, from a few watts to over 250 W. Rated power is determined by the output voltage and current under standard sun intensity.

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