<>
Direct-burial wire (UF), grounding, disconnects. Excess power produced by solar panels can be used for cathode protection, to aerate a dugout, or to power an electric fence. For example, a summer tilt angle would be flatter to capture more sun with tilt angle equal to the latitude angle -15 while a winter tilt angle might be latitude angle +15.
12 0 obj 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. 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.
Foster, R., M. Ghassemi, and A. Cota.
$.' To find more resources for your business, home, or family, visit the College of Agricultural, Consumer and Environmental Sciences on the World Wide Web atpubs.nmsu.edu. Another standard rule of thumb is that friction losses in the pipe are typically 25% for a well-designed system. The required capacity or flow ratehow many gallons per minute (or per day) are needed. A controller that allows the pump to start and operate under weak-sunlight periods (cloudy conditions, early morning, late afternoon). Literature and educational multimedia materials related to PV water pumping systems (https://www.youtube.com/playlist?list=PL89870B418A514D27), including comparisons between three main remote water pumping technologies (Table 1) used in New Mexico today, contrasting two different ways to mount PV modules (fixed-angle mounting vs. single-axis tracking systems), and a simple cost analysis for each of the three technologies and mounting systems (Foster et al., 2010). Buschermohle, M., and R. Burns. <>
Nevertheless, you can choose to use the summer insolation value if you plan to water a summer-only pasture. This may be fixed or variable depending on seasonal conditions and other factors. ), Figure 4. In the case of design values outside these limits or for pumps or PV module choices not available within the spreadsheet, you should reference alternative performance data provided by other pump or PV manufacturers. 12 All areas of New Mexico meet this limit with values well above 5 kWh/m2 per day. 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). Calves require higher-quality water and will not fight cows or mud to obtain it. 7 0 obj
Hoboken, NJ: John Wiley & Sons, Inc. Morris, M., and V. Lynne. 9 0 obj 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.
endobj Livestock, crops, and people often depend upon surface sources of water (streams, ponds, catch tanks, etc.) A solar pumping system involves calculations and concepts that may make it difficult to determine a design if one is unfamiliar with the technology and terminologies. 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. 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. These entries and Equation 1 are used to calculate total daily water required for each animal type (item). Space, weight, and position limitations, as well as cost of equipment and installation. Figure 3. The conditions on the suction side of the pump (lots of grit, sand, or dissolved minerals in the water; algae growth; etc.). endobj xZ[oH~G? %PDF-1.5 % When you insert this value, the spreadsheet determines the solar insolation for winter, summer, or a yearly average. Choosing and matching PV modules and pumps to meet the design constraints is vital. Contents of publications may be freely reproduced for educational purposes. These friction losses, which are expressed in equivalent lengths of vertical pipe distance, are added to the static head to yield an equivalent TDHi.e., what equivalent height would the pump need to move water given these values. The storage tank size is calculated by multiplying the days-of-storage requirement by the daily water requirement and is provided as a reference only. These are then summed to give a total loss due to fittings (Mott, 2006). endobj
Disclaimer: This document is intended for educational purposes only in providing a basic understanding of terminology and concepts of design. endobj 
stream
), nitrogen, phosphorous, suspended solids, and surrounding erosion are realized. or wells accessing underground aquifers1. 1 0 obj
Available from https://www.clemson.edu/sustainableag/IP217_solar_livestock_watering.pdf. <>/ExtGState<>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>>
endobj This tool allows the user to follow the basic step-by-step design process, and offers sample components and simple economic analysis for a user-defined scenario. 0
3 0 obj
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. For permission to use publications for other purposes, contact pubs@nmsu.edu or the authors listed on the publication. hbbd``b`v@IHp@u B
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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. Locating modules close to the water source also helps minimize power losses and costs. The water level variable in Equation 2 is measured from the water surface to the level of the water in the sourcenot the depth location of the pump. Solar pumping systems for surface sources or wells can be portable, which is appealing because more and more producers want systems that can move among various locations. Storage systemscatch tanks, concrete or plastic storage tanks, etc.to ensure the daily water requirement is available during low-light conditions. endobj In addition to increased livestock and resource performance, by routing the livestock away from riparian zones, very large reductions (5090%) in streptococci and coliform fecal organisms, waterborne diseases (foot rot, red nose, TB, mastitis, etc. Daily water requirements and usagedrinking, irrigation, etc. 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. NMSU and the U.S. Department of Agriculture cooperating. 2006. Electricity when and where you need it: From the sun: Photovoltaics for farms and ranches [Online; NREL/BR-412-21732]. Placing the pump lower in the well (increasing its submergence) will NOT cause it to work harder or to pump less water, nor will it increase stress or wear on the pump. Depending on climate and usage, storage tank capacity should equal 3 to 10 days of water use. Increases of 50 pounds/head in weaning weight have been reported when water in sufficient quantity and quality is provided. The Array Sizing spreadsheet tab involves the automatic sizing of the PV array given the calculated and manually selected pump parameters.
New Mexico climate website (https://weather.nmsu.edu) has good historical solar, wind, and temperature data. Applied fluid mechanics (6 ed.). 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. One approach is to remove or limit access to these areas; however, often this is the only viable water source for producers. Air temperatures of 70 to 95F may increase water requirements by 2.5 times (Pfost et al., 2007). The author wishes to express extreme gratitude for the assistance of the following: College of Engineering and Engineering NM: https://engr.nmsu.edu/index.shtml, NMSU Cooperative Extension Service: https://extension.nmsu.edu/, New Mexico Space Grant Consortium: https://www.nmspacegrant.com/. Solar systems low maintenance and simple operation, lack of fuel (transportation or storage) costs, environmental friendliness, and competitive life-cycle economics place them at the forefront of choices for supplying water to livestock or agriculture. Research also shows that yearling steer performance increased 23% when supplied with an alternate water source rather than dugouts (earthen dams or reservoirs). Each PV module has an operating output current and voltage. This is the power that de-rated 14 PV modules must supply to operate the pump. 4 0 obj 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. 2004. 1An excellent source on windmills: https://aces.nmsu.edu/ces/windmill. Solar-powered livestock watering system [Online]. Mott, R.L. The abundant and varied benefits of PV systems make them attractive in many situations. All other rights reserved. By providing storage, a producer can still provide their daily water requirements from the storage tank at night or on cloudy days. For the sake of organization and ease of use, the spreadsheet follows the design approach outlined in this publication. The market price for the UF wire is for 250-ft rolls. 24 0 obj The technology for solar water pumping is exceeding all expectations, and will continue to be a viable choice for more and more users as its capabilities, reliability, and versatility increase while costs decrease. This is typically not an issue when float switches are incorporated into storage systems, which will stop the pumping when the tank is full. Equation 3 illustrates the Hazen-Williams formula. Wiles, J. As demands for higher quantities and quality of water, lower costs, improved reliability, and environmental concerns have increased, many livestock and agricultural producers are investigating an alternative technology for remote water pumping: direct-coupled solar photovoltaic (PV) powered systems.
Studies have shown that, when given a choice, cattle drank from a water trough 92% of the time rather than from a nearby stream (Bartlett, n.d.). endobj x+*@02,L-T5300700THMLO5PpW M 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. In the Pump Selection tab of the spreadsheet, you are shown the calculated Q and TDH. 10See your NMSU county Extension agent for more information.
?r=z'{sEB2PdOvhvZ0!0g)_qe\MqZ6n[;&ol: rKp1 Codes and standards, including the National Electrical Code (Wiles, 2001). A good rule of thumb is that the solar resource must be greater than 3.0 kWh/m2 per day (3,000 watt-hours per square meter of area in one day) for choosing a solar 12. Livestocks daily water requirements vary with air temperature, the animals age and size, activity, distance to water, lactation, dry matter intake, and dry matter moisture content. Direct-coupled solar pumping system. Oxford: Oxford University Press. 11Contact your county Extension agent for information on estimated evapotranspiration rates for your area. Water consumption is almost directly proportional to the level of milk production, and lactating cows therefore need higher amounts of water. <>/Metadata 656 0 R/ViewerPreferences 657 0 R>> 2. The well is 80 ft from the storage tank, and the delivery pipe rises 8 ft to discharge into a tank. Surber, G., K. Williams, and M. Manoukian. Each module is portable and therefore available for displays and presentations. While cows may wade out to obtain better water, calves tend to only drink from the shore. PV panels are installed with mounting hardware that allows the panels to be oriented 6 to adjust the tilt of the modules to an optimum angle, elevate the modules for security, and minimize shading and damage (Figure 4). If it is between 1,500 and 2,000 m4, it will be borderline. endobj 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. To determine these losses, the spreadsheet lists many common fittings that might be utilized within the design of the system, and you should enter the quantity of each fitting used in your system. However, there are reasons to NOT set the pump too close to the bottom of the well: 1.
2 0 obj 13 0 obj Figure 2. Securityalthough ideal for remote locations, systems may be vulnerable to theft and vandalism. endobj <> In areas where connection to an electric utility is not available, the primary technologies for water accesssurface sources or pumpinghave remained fairly constant for decades. In selecting a pump, the following parameters should be considered: Once each parameter is clearly addressed, a pump can be selected.
By pumping water to drinkers, ranchers can better utilize pastures, get superior animal growth and health, and provide higher-quality water (Pfost et al., 2007; Surber et al., n.d.). With this in mind, NMSU developed the following tools to aid and educate a potential user: 1. endobj The cost for each itemized component is calculated by multiplying the quantity of each item by a representative retail price, but prices will of course vary over time. Windmills are still a common source of power for off-the-grid water pumping systems. Low levels of sun may limit PV. <> Renewable energy.
Photovoltaic power systems and the National Electrical Code: Suggested practices [SAND87-0804]. r)4LY6D The amount of water pumped depends primarily on the amount of sunlight hitting the PV panels, the type of pump, and a few other factors. Circular 670 Thomas Jenkins College of Agricultural, Consumer and Environmental Sciences and College of Engineering, New Mexico State University. and how much power (watts) is required to run this pump assuming standard pump efficiency ( ~35%).
The equivalent head pipe friction loss values are calculated for each specific fitting used. 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. To determine Daily Water Requirement using the spreadsheet tool, enter the quantity and type of animals (cow, horse, etc.) What is the TDH in a well with water depth of 150 ft (no draw-down) and flow rate of 4 gpm? 5PV panels may produce up to 80% of their maximum output power on partly cloudy days, and even on extremely overcast days can still produce about 25% of their maximum. 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 ). % 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. Modules can be wired in series to increase output voltages and in parallel to increase current while also increasing total power. 8 0 obj 16 0 obj By understanding these basic concepts beforehand, the designer will be able to determine the appropriate pump (and PV modules) for a system. endobj %PDF-1.7 11 0 obj 2001. This includes: With no moving parts, the PV panel takes energy from sunlight and generates DC electricity, which is then directed through a controller to the pump/motor in what is termed a direct-coupled system (Figure 2).
2002. NOTE: It is possible that there will only need to be a single module or modules only in series and not in parallel.
endstream endobj startxref This will reflect an approximate cost to construct the system plus the costs of other materials, labor, sales taxes, shipping, etc. Available from https://www.nrel.gov/docs/fy03osti/30361.pdf. Solar pumping, like windmills, will pump water at slower flow rates (gpm) over a longer time. OPSdG."l is calculated by adding up all the itemized totals. One U.S. gallon is equal to about 0.0037854 cubic meters, while 1 foot of distance is equal to about 0.3048 meters. 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. endobj
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. Pumps are classified as either positive-displacement or kinetic/centrifugal, and each has advantages. <> This direct-coupled system is intended to operate only during the day when sunlight is present, thus eliminating the expense and complexity of batteries 4. Pump power can often be looked up in pump tables, but it can also be determined by Equation 8. In many parts of the world, including New Mexico (NM), water and energy availability are growing concerns. 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. Renewable energy for water pumping applications in rural villages [Online; NREL/SR-500-30361]. Some users are even powering broken windmill pump jacks with portable photovoltaic (PV) systems. \aAhx` MwWE:)2btBtq:Ed[1ctX,LaqpDag s,~|OjVJ9`G T0/2FduB'J."W. 18 0 obj The low flow rates of solar systems have less negative impact on draw-down. hb``b``0bl,3/e@ <> The total head capability (how high can the pump move water). #(4/g&ww6?wI:W9YZt}iVE?3Z.r. Bartlett, B. n.d. Watering systems for grazing livestock [Online]. endobj If we convert TDH from feet to meters and the daily water volume from gallons to cubic meters, then we can calculate something called the hydraulic workload (Equation 6), which is an excellent indication of the power that will be required to meet the designed system constraints. National Renewable Energy Labs. Once the daily water requirement is calculated, the solar resourceinsolation, or total sunlight reaching a specific locationis determined. In Las Cruces, the latitude angle would be 32 tilt, a summer tilt of 17, and a winter tilt of 47. 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). <>
Knowing head, you can determine pressure and vice versa.
<>/Font<>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI]>>/Parent 24 0 R/Group<>/Annots[]/Type/Page/Tabs/S>> The approximate head loss (HL) caused by friction within the pipe is calculated using the Hazen-Williams Empirical formula with assumptions of mediocre water temperature and somewhat turbulent pipe flow. 2. Irrigation water demand depends on local conditions, season, crops, methods of delivery, and evapotranspiration 11. A multiplier may be added that can provide an extra water cushion, offset evaporation losses, or refill the storage tank. By using a simple direct-coupled approach, the operation, maintenance, costs, and complexity of the system are greatly reduced. Italicized text (e.g., Daily Water Requirement) refers to sheets in the spreadsheet; sheets are accessed using the tabs at the bottom of the spreadsheet window.
endobj Once the total gallons/day/animal figure is calculated and any extra water requirements are entered, values are summed to yield the total daily water requirement in gallons/day. The spreadsheet, documentation, and demonstration modules provide you with terminologies, knowledge, and skill sets that can be the foundation for informed choices relating to alternative water pumping systems. Photovoltaic-powered water pumping systems are attractive for livestock and agricultural producers with remote water sources and limited access to AC power. Boca Raton, FL: Taylor & Francis Group. A setting near the bottom may increase the chance of sand or sediment being drawn into the pump and damaging the pump mechanism. endobj Federal and state tax incentives may lower the initial costs by up to 40% (as of 2012). Fortunately, research shows that in many cases pumping water to a different location, combined with a managed rotational grazing plan 2, optimizes animal performance, pasture use, water quality, and wildlife in these zones (Buschermohle and Burns, n.d.; Morris and Lynne, 2002). Boyle, G. 2004. Solar water pumping systems are composed of two primary components other than the well itself: the PV panels (or modules) and the pump. you wish to service from this well.
The necessary length of UF wire is roughly determined by the length of pipe plus an extra 25%.
<> The water must be lifted 150 + 8 = 158 ft (static head); therefore, TDH (Equation 5) is 158 + 11.74 + 14.6 = ~184 ft. Oftentimes, we may work in units other than gallons and feet. Water needs closely correspond to quantity of feed or forage intake; as intake increases, the water requirement level will increase. (Photo from National Renewable Energy Labs, 1997.). <> Albuquerque, NM: Sandia National Laboratories. Professor Jenkins lead the effort to develop the College of Engineering Renewable Energy Technology minor and helped establish the NMSU student organization Engineers Without Borders. The description and quantities for specific items are obtained from calculations or specified by you. A good match between the pump, PV array, and system parameters is necessary to achieve efficient operation (Morris et al., 2002).
We hope that later versions of this spreadsheet will address several of these issues. The list of available pumps (and manufacturers) is very extensive, and many will be capable of pumping from a surface source or a well. Requirements for high volumes or flow rates may limit applications. (Adapted from The University of Tennessee Extension.). <> Excessive livestock pressure on surface sources often causes nutrient loading, streamside vegetation damage, erosion, pollution, and decreased animal growth and health. 20 0 obj 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. NOTE: These values are for a pre-selected example PV module. pipe at 4 gpm has a pressure drop of 4.9 ft/100 ft of tube, which yields 4.9 238 / 100 = ~11.74 ft. 4 0 obj <> In addition, these factors should be considered: Who will install and maintain the system. 6 0 obj Available from https://www.nrel.gov/docs/gen/fy97/21732.pdf, Pfost, D., J. Gerrish, M. Davis, and M. Kennedy. PV-powered pump systems often discharge to a storage tank to provide the daily water requirement even under lowlight conditions. This section will reference the accompanying Excel spreadsheet covered in Circular 671 (available to download at https://pubs.nmsu.edu/_circulars/CR671/CR671.xlsx). 43 0 obj <> endobj <> 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 This publication provides a general discussion of how to design a photovoltaic-powered solar water pumping system for livestock. One-half- to two-inch piping is typically sufficient for most scenarios; smaller is cheaper and often more efficient. 2007.
endobj
113 0 obj <>stream Drinking water quality for beef cattle: An environment friendly & production management enhancement technique [Online]. TDH can now be calculated by using Equation 5. Solar pumps are low volume, pumping an average of 1 to 5 gallons per minute (gpm). WlU Pumps and watering systems for managed beef grazing [Online]. <>/ProcSet 26 0 R>>/Type/XObject>>stream He previously worked for many years in both private and public sectors as a computer scientist and engineer. <> The equivalent friction loss for each fitting type is calculated using Equation 4. ",#(7),01444'9=82. 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. Water pressure is expressed in pounds per square inch (psi) and is defined as the force caused by the weight of water in a column of a certain height, also known as head. Head is a term relating feet of water in a column that exerts a certain pressure; for example, a column of water 10 ft high would exert 10 ft of head, or 4.3 psi (pressure). ), total length of the pipe being used, and the nominal inside diameter of the pipe. Pumps move water from wells or surface sources.
In remote locations, though, PV water pumping systems represent a very attractive, long-term, cost-effective alternative to hauling water, diesel pumps, and even traditional windmills for drinking water and many irrigation applications (drip/trickle, hose/basin, and some channel irrigationalthough typically not for very high flow rates such as might be used in flood irrigation). 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 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. endobj 3It can cost $10,000 to $30,000 per mile to install electrical power line through rugged terrain. The amount of available sunlight is predictable by location, but there are always variations in weather (e.g., cloudy days 5). For additional information, contact your county Cooperative Extension agent or NMSU. The first step in a design is to determine the total amount of water needed per day.
12 0 obj 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. 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.
Foster, R., M. Ghassemi, and A. Cota.
$.' To find more resources for your business, home, or family, visit the College of Agricultural, Consumer and Environmental Sciences on the World Wide Web atpubs.nmsu.edu. Another standard rule of thumb is that friction losses in the pipe are typically 25% for a well-designed system. The required capacity or flow ratehow many gallons per minute (or per day) are needed. A controller that allows the pump to start and operate under weak-sunlight periods (cloudy conditions, early morning, late afternoon). Literature and educational multimedia materials related to PV water pumping systems (https://www.youtube.com/playlist?list=PL89870B418A514D27), including comparisons between three main remote water pumping technologies (Table 1) used in New Mexico today, contrasting two different ways to mount PV modules (fixed-angle mounting vs. single-axis tracking systems), and a simple cost analysis for each of the three technologies and mounting systems (Foster et al., 2010). Buschermohle, M., and R. Burns. <>
Nevertheless, you can choose to use the summer insolation value if you plan to water a summer-only pasture. This may be fixed or variable depending on seasonal conditions and other factors. ), Figure 4. In the case of design values outside these limits or for pumps or PV module choices not available within the spreadsheet, you should reference alternative performance data provided by other pump or PV manufacturers. 12 All areas of New Mexico meet this limit with values well above 5 kWh/m2 per day. 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). Calves require higher-quality water and will not fight cows or mud to obtain it. 7 0 obj Hoboken, NJ: John Wiley & Sons, Inc. Morris, M., and V. Lynne. 9 0 obj 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.
endobj Livestock, crops, and people often depend upon surface sources of water (streams, ponds, catch tanks, etc.) A solar pumping system involves calculations and concepts that may make it difficult to determine a design if one is unfamiliar with the technology and terminologies. 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. 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. These entries and Equation 1 are used to calculate total daily water required for each animal type (item). Space, weight, and position limitations, as well as cost of equipment and installation. Figure 3. The conditions on the suction side of the pump (lots of grit, sand, or dissolved minerals in the water; algae growth; etc.). endobj xZ[oH~G? %PDF-1.5 % When you insert this value, the spreadsheet determines the solar insolation for winter, summer, or a yearly average. Choosing and matching PV modules and pumps to meet the design constraints is vital. Contents of publications may be freely reproduced for educational purposes. These friction losses, which are expressed in equivalent lengths of vertical pipe distance, are added to the static head to yield an equivalent TDHi.e., what equivalent height would the pump need to move water given these values. The storage tank size is calculated by multiplying the days-of-storage requirement by the daily water requirement and is provided as a reference only. These are then summed to give a total loss due to fittings (Mott, 2006). endobj
Disclaimer: This document is intended for educational purposes only in providing a basic understanding of terminology and concepts of design. endobj stream
), nitrogen, phosphorous, suspended solids, and surrounding erosion are realized. or wells accessing underground aquifers1. 1 0 obj
Available from https://www.clemson.edu/sustainableag/IP217_solar_livestock_watering.pdf. <>/ExtGState<>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>>
endobj This tool allows the user to follow the basic step-by-step design process, and offers sample components and simple economic analysis for a user-defined scenario. 0
3 0 obj
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. For permission to use publications for other purposes, contact pubs@nmsu.edu or the authors listed on the publication. hbbd``b`v@IHp@u B
H0,A@bA R"ZAb@BHpG $ RHp \, A 2 2$"@A,s dAEg~` $$
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. Locating modules close to the water source also helps minimize power losses and costs. The water level variable in Equation 2 is measured from the water surface to the level of the water in the sourcenot the depth location of the pump. Solar pumping systems for surface sources or wells can be portable, which is appealing because more and more producers want systems that can move among various locations. Storage systemscatch tanks, concrete or plastic storage tanks, etc.to ensure the daily water requirement is available during low-light conditions. endobj In addition to increased livestock and resource performance, by routing the livestock away from riparian zones, very large reductions (5090%) in streptococci and coliform fecal organisms, waterborne diseases (foot rot, red nose, TB, mastitis, etc. Daily water requirements and usagedrinking, irrigation, etc. 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. NMSU and the U.S. Department of Agriculture cooperating. 2006. Electricity when and where you need it: From the sun: Photovoltaics for farms and ranches [Online; NREL/BR-412-21732]. Placing the pump lower in the well (increasing its submergence) will NOT cause it to work harder or to pump less water, nor will it increase stress or wear on the pump. Depending on climate and usage, storage tank capacity should equal 3 to 10 days of water use. Increases of 50 pounds/head in weaning weight have been reported when water in sufficient quantity and quality is provided. The Array Sizing spreadsheet tab involves the automatic sizing of the PV array given the calculated and manually selected pump parameters. New Mexico climate website (https://weather.nmsu.edu) has good historical solar, wind, and temperature data. Applied fluid mechanics (6 ed.). 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. One approach is to remove or limit access to these areas; however, often this is the only viable water source for producers. Air temperatures of 70 to 95F may increase water requirements by 2.5 times (Pfost et al., 2007). The author wishes to express extreme gratitude for the assistance of the following: College of Engineering and Engineering NM: https://engr.nmsu.edu/index.shtml, NMSU Cooperative Extension Service: https://extension.nmsu.edu/, New Mexico Space Grant Consortium: https://www.nmspacegrant.com/. Solar systems low maintenance and simple operation, lack of fuel (transportation or storage) costs, environmental friendliness, and competitive life-cycle economics place them at the forefront of choices for supplying water to livestock or agriculture. Research also shows that yearling steer performance increased 23% when supplied with an alternate water source rather than dugouts (earthen dams or reservoirs). Each PV module has an operating output current and voltage. This is the power that de-rated 14 PV modules must supply to operate the pump. 4 0 obj 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. 2004. 1An excellent source on windmills: https://aces.nmsu.edu/ces/windmill. Solar-powered livestock watering system [Online]. Mott, R.L. The abundant and varied benefits of PV systems make them attractive in many situations. All other rights reserved. By providing storage, a producer can still provide their daily water requirements from the storage tank at night or on cloudy days. For the sake of organization and ease of use, the spreadsheet follows the design approach outlined in this publication. The market price for the UF wire is for 250-ft rolls. 24 0 obj The technology for solar water pumping is exceeding all expectations, and will continue to be a viable choice for more and more users as its capabilities, reliability, and versatility increase while costs decrease. This is typically not an issue when float switches are incorporated into storage systems, which will stop the pumping when the tank is full. Equation 3 illustrates the Hazen-Williams formula. Wiles, J. As demands for higher quantities and quality of water, lower costs, improved reliability, and environmental concerns have increased, many livestock and agricultural producers are investigating an alternative technology for remote water pumping: direct-coupled solar photovoltaic (PV) powered systems.
Studies have shown that, when given a choice, cattle drank from a water trough 92% of the time rather than from a nearby stream (Bartlett, n.d.). endobj x+*@02,L-T5300700THMLO5PpW M 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. In the Pump Selection tab of the spreadsheet, you are shown the calculated Q and TDH. 10See your NMSU county Extension agent for more information.
?r=z'{sEB2PdOvhvZ0!0g)_qe\MqZ6n[;&ol: rKp1 Codes and standards, including the National Electrical Code (Wiles, 2001). A good rule of thumb is that the solar resource must be greater than 3.0 kWh/m2 per day (3,000 watt-hours per square meter of area in one day) for choosing a solar 12. Livestocks daily water requirements vary with air temperature, the animals age and size, activity, distance to water, lactation, dry matter intake, and dry matter moisture content. Direct-coupled solar pumping system. Oxford: Oxford University Press. 11Contact your county Extension agent for information on estimated evapotranspiration rates for your area. Water consumption is almost directly proportional to the level of milk production, and lactating cows therefore need higher amounts of water. <>/Metadata 656 0 R/ViewerPreferences 657 0 R>> 2. The well is 80 ft from the storage tank, and the delivery pipe rises 8 ft to discharge into a tank. Surber, G., K. Williams, and M. Manoukian. Each module is portable and therefore available for displays and presentations. While cows may wade out to obtain better water, calves tend to only drink from the shore. PV panels are installed with mounting hardware that allows the panels to be oriented 6 to adjust the tilt of the modules to an optimum angle, elevate the modules for security, and minimize shading and damage (Figure 4). If it is between 1,500 and 2,000 m4, it will be borderline. endobj 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. To determine these losses, the spreadsheet lists many common fittings that might be utilized within the design of the system, and you should enter the quantity of each fitting used in your system. However, there are reasons to NOT set the pump too close to the bottom of the well: 1.
2 0 obj 13 0 obj Figure 2. Securityalthough ideal for remote locations, systems may be vulnerable to theft and vandalism. endobj <> In areas where connection to an electric utility is not available, the primary technologies for water accesssurface sources or pumpinghave remained fairly constant for decades. In selecting a pump, the following parameters should be considered: Once each parameter is clearly addressed, a pump can be selected.
By pumping water to drinkers, ranchers can better utilize pastures, get superior animal growth and health, and provide higher-quality water (Pfost et al., 2007; Surber et al., n.d.). With this in mind, NMSU developed the following tools to aid and educate a potential user: 1. endobj The cost for each itemized component is calculated by multiplying the quantity of each item by a representative retail price, but prices will of course vary over time. Windmills are still a common source of power for off-the-grid water pumping systems. Low levels of sun may limit PV. <> Renewable energy.
Photovoltaic power systems and the National Electrical Code: Suggested practices [SAND87-0804]. r)4LY6D The amount of water pumped depends primarily on the amount of sunlight hitting the PV panels, the type of pump, and a few other factors. Circular 670 Thomas Jenkins College of Agricultural, Consumer and Environmental Sciences and College of Engineering, New Mexico State University. and how much power (watts) is required to run this pump assuming standard pump efficiency ( ~35%).
The equivalent head pipe friction loss values are calculated for each specific fitting used. 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. To determine Daily Water Requirement using the spreadsheet tool, enter the quantity and type of animals (cow, horse, etc.) What is the TDH in a well with water depth of 150 ft (no draw-down) and flow rate of 4 gpm? 5PV panels may produce up to 80% of their maximum output power on partly cloudy days, and even on extremely overcast days can still produce about 25% of their maximum. 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 ). % 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. Modules can be wired in series to increase output voltages and in parallel to increase current while also increasing total power. 8 0 obj 16 0 obj By understanding these basic concepts beforehand, the designer will be able to determine the appropriate pump (and PV modules) for a system. endobj %PDF-1.7 11 0 obj 2001. This includes: With no moving parts, the PV panel takes energy from sunlight and generates DC electricity, which is then directed through a controller to the pump/motor in what is termed a direct-coupled system (Figure 2).
2002. NOTE: It is possible that there will only need to be a single module or modules only in series and not in parallel.
endstream endobj startxref This will reflect an approximate cost to construct the system plus the costs of other materials, labor, sales taxes, shipping, etc. Available from https://www.nrel.gov/docs/fy03osti/30361.pdf. Solar pumping, like windmills, will pump water at slower flow rates (gpm) over a longer time. OPSdG."l is calculated by adding up all the itemized totals. One U.S. gallon is equal to about 0.0037854 cubic meters, while 1 foot of distance is equal to about 0.3048 meters. 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. endobj
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. Pumps are classified as either positive-displacement or kinetic/centrifugal, and each has advantages. <> This direct-coupled system is intended to operate only during the day when sunlight is present, thus eliminating the expense and complexity of batteries 4. Pump power can often be looked up in pump tables, but it can also be determined by Equation 8. In many parts of the world, including New Mexico (NM), water and energy availability are growing concerns. 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. Renewable energy for water pumping applications in rural villages [Online; NREL/SR-500-30361]. Some users are even powering broken windmill pump jacks with portable photovoltaic (PV) systems. \aAhx` MwWE:)2btBtq:Ed[1ctX,LaqpDag s,~|OjVJ9`G T0/2FduB'J."W. 18 0 obj The low flow rates of solar systems have less negative impact on draw-down. hb``b``0bl,3/e@ <> The total head capability (how high can the pump move water). #(4/g&ww6?wI:W9YZt}iVE?3Z.r. Bartlett, B. n.d. Watering systems for grazing livestock [Online]. endobj If we convert TDH from feet to meters and the daily water volume from gallons to cubic meters, then we can calculate something called the hydraulic workload (Equation 6), which is an excellent indication of the power that will be required to meet the designed system constraints. National Renewable Energy Labs. Once the daily water requirement is calculated, the solar resourceinsolation, or total sunlight reaching a specific locationis determined. In Las Cruces, the latitude angle would be 32 tilt, a summer tilt of 17, and a winter tilt of 47. 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). <>
Knowing head, you can determine pressure and vice versa.
<>/Font<>/ExtGState<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI]>>/Parent 24 0 R/Group<>/Annots[]/Type/Page/Tabs/S>> The approximate head loss (HL) caused by friction within the pipe is calculated using the Hazen-Williams Empirical formula with assumptions of mediocre water temperature and somewhat turbulent pipe flow. 2. Irrigation water demand depends on local conditions, season, crops, methods of delivery, and evapotranspiration 11. A multiplier may be added that can provide an extra water cushion, offset evaporation losses, or refill the storage tank. By using a simple direct-coupled approach, the operation, maintenance, costs, and complexity of the system are greatly reduced. Italicized text (e.g., Daily Water Requirement) refers to sheets in the spreadsheet; sheets are accessed using the tabs at the bottom of the spreadsheet window.
endobj Once the total gallons/day/animal figure is calculated and any extra water requirements are entered, values are summed to yield the total daily water requirement in gallons/day. The spreadsheet, documentation, and demonstration modules provide you with terminologies, knowledge, and skill sets that can be the foundation for informed choices relating to alternative water pumping systems. Photovoltaic-powered water pumping systems are attractive for livestock and agricultural producers with remote water sources and limited access to AC power. Boca Raton, FL: Taylor & Francis Group. A setting near the bottom may increase the chance of sand or sediment being drawn into the pump and damaging the pump mechanism. endobj Federal and state tax incentives may lower the initial costs by up to 40% (as of 2012). Fortunately, research shows that in many cases pumping water to a different location, combined with a managed rotational grazing plan 2, optimizes animal performance, pasture use, water quality, and wildlife in these zones (Buschermohle and Burns, n.d.; Morris and Lynne, 2002). Boyle, G. 2004. Solar water pumping systems are composed of two primary components other than the well itself: the PV panels (or modules) and the pump. you wish to service from this well.
The necessary length of UF wire is roughly determined by the length of pipe plus an extra 25%.
<> The water must be lifted 150 + 8 = 158 ft (static head); therefore, TDH (Equation 5) is 158 + 11.74 + 14.6 = ~184 ft. Oftentimes, we may work in units other than gallons and feet. Water needs closely correspond to quantity of feed or forage intake; as intake increases, the water requirement level will increase. (Photo from National Renewable Energy Labs, 1997.). <> Albuquerque, NM: Sandia National Laboratories. Professor Jenkins lead the effort to develop the College of Engineering Renewable Energy Technology minor and helped establish the NMSU student organization Engineers Without Borders. The description and quantities for specific items are obtained from calculations or specified by you. A good match between the pump, PV array, and system parameters is necessary to achieve efficient operation (Morris et al., 2002).
We hope that later versions of this spreadsheet will address several of these issues. The list of available pumps (and manufacturers) is very extensive, and many will be capable of pumping from a surface source or a well. Requirements for high volumes or flow rates may limit applications. (Adapted from The University of Tennessee Extension.). <> Excessive livestock pressure on surface sources often causes nutrient loading, streamside vegetation damage, erosion, pollution, and decreased animal growth and health. 20 0 obj 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. NOTE: These values are for a pre-selected example PV module. pipe at 4 gpm has a pressure drop of 4.9 ft/100 ft of tube, which yields 4.9 238 / 100 = ~11.74 ft. 4 0 obj <> In addition, these factors should be considered: Who will install and maintain the system. 6 0 obj Available from https://www.nrel.gov/docs/gen/fy97/21732.pdf, Pfost, D., J. Gerrish, M. Davis, and M. Kennedy. PV-powered pump systems often discharge to a storage tank to provide the daily water requirement even under lowlight conditions. This section will reference the accompanying Excel spreadsheet covered in Circular 671 (available to download at https://pubs.nmsu.edu/_circulars/CR671/CR671.xlsx). 43 0 obj <> endobj <> 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 This publication provides a general discussion of how to design a photovoltaic-powered solar water pumping system for livestock. One-half- to two-inch piping is typically sufficient for most scenarios; smaller is cheaper and often more efficient. 2007.
endobj
113 0 obj <>stream Drinking water quality for beef cattle: An environment friendly & production management enhancement technique [Online]. TDH can now be calculated by using Equation 5. Solar pumps are low volume, pumping an average of 1 to 5 gallons per minute (gpm). WlU Pumps and watering systems for managed beef grazing [Online]. <>/ProcSet 26 0 R>>/Type/XObject>>stream He previously worked for many years in both private and public sectors as a computer scientist and engineer. <> The equivalent friction loss for each fitting type is calculated using Equation 4. ",#(7),01444'9=82. 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. Water pressure is expressed in pounds per square inch (psi) and is defined as the force caused by the weight of water in a column of a certain height, also known as head. Head is a term relating feet of water in a column that exerts a certain pressure; for example, a column of water 10 ft high would exert 10 ft of head, or 4.3 psi (pressure). ), total length of the pipe being used, and the nominal inside diameter of the pipe. Pumps move water from wells or surface sources.
In remote locations, though, PV water pumping systems represent a very attractive, long-term, cost-effective alternative to hauling water, diesel pumps, and even traditional windmills for drinking water and many irrigation applications (drip/trickle, hose/basin, and some channel irrigationalthough typically not for very high flow rates such as might be used in flood irrigation). 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 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. endobj 3It can cost $10,000 to $30,000 per mile to install electrical power line through rugged terrain. The amount of available sunlight is predictable by location, but there are always variations in weather (e.g., cloudy days 5). For additional information, contact your county Cooperative Extension agent or NMSU. The first step in a design is to determine the total amount of water needed per day.