Photovoltaic Power Water Pumping Systems
6
1 Photovoltaic Power Water Pumping Systems DC Surface Pump for Livestock Watering Rural electric cooperatives in the United States are beginning to supply PV power to their customers who need to pump water for livestock. The conventional method of service was to extend the grid line to the isolated well & emdash, even though the income from the customer could never pay for the maintenance of the line, let alone provide a return on the original investment. As these remote lines require replacement, either because of age or storm damage, a number of utilities have discovered that a PV pumping system can be provided for the customer at a fraction of the cost of replacing the line. This example is of a rancher in Nebraska that requires about 500 gallons of water per day for 40 cows. The pasture where the well is located is used in wintertime only there is a 2,500 gallon tank near the well that provides water (gravity fed) to smaller water tanks distributed throughout the pasture. The load is critical as the cattle cannot go without water more than one day in winter. This small pump uses a 12 volt dc two stage diaphragm pump and is designed to pump over 500 gallon per day (~ 2,000 liters per day) from a level of 20 meters. The water level in this well is only 10 meters with a maximum drawdown of 6 meters. A float switch in the main watering tank controls operation of the pump. Site Potter, Nebraska Location/Elevation 40°N - 103° W - 200 meters Environment Grassland Temperature Range (°C) -10 to 35 Maximum Wind Speed (m/s) 20 Availability Required near 100 percent (critical) Days of Storage 4 - Fiberglass Tank Source Cased 3-inch Borehole Dynamic Head (m) 17 Water Required 2000 liters/day (500 gpd) October to March Installation The PV modules are mounted on a passively controlled tracking structure and tilted at 55° for maximum winter performance. Sunlight resistant USE wire is used to interconnect the modules. A switch box was attached to the pole and the linear current booster was installed in the box. The pump was attached to 2-inch plastic pipe and installed in the 3-inch bore hole. A float switch was installed near the top of the holding tank and the control cables are protected from damage by conduit. The system was grounded to the well casing using a short length of No. 6 stranded copper wire. Worksheet 1-Calculate Water Pumping Load
-
Upload
salem-ben-moussa -
Category
Documents
-
view
20 -
download
2
description
Photovoltaic Power Water Pumping Systems
Transcript of Photovoltaic Power Water Pumping Systems
1
Photovoltaic Power Water Pumping Systems
DC Surface Pump for Livestock Watering
Rural electric cooperatives in the United States are beginning to supply PV power to
their customers who need to pump water for livestock. The conventional method of
service was to extend the grid line to the isolated well & emdash, even though the
income from the customer could never pay for the maintenance of the line, let alone
provide a return on the original investment. As these remote lines require
replacement, either because of age or storm damage, a number of utilities have
discovered that a PV pumping system can be provided for the customer at a fraction
of the cost of replacing the line. This example is of a rancher in Nebraska that requires
about 500 gallons of water per day for 40 cows. The pasture where the well is located
is used in wintertime only there is a 2,500 gallon tank near the well that provides
water (gravity fed) to smaller water tanks distributed throughout the pasture. The load
is critical as the cattle cannot go without water more than one day in winter. This
small pump uses a 12 volt dc two stage diaphragm pump and is designed to pump
over 500 gallon per day (~ 2,000 liters per day) from a level of 20 meters. The water
level in this well is only 10 meters with a maximum drawdown of 6 meters. A float
switch in the main watering tank controls operation of the pump.
Site Potter, Nebraska
Location/Elevation 40°N - 103° W - 200 meters
Environment Grassland
Temperature Range (°C) -10 to 35
Maximum Wind Speed (m/s) 20
Availability Required near 100 percent (critical)
Days of Storage 4 - Fiberglass Tank
Source Cased 3-inch Borehole
Dynamic Head (m) 17
Water Required 2000 liters/day (500 gpd) October to March
Installation
The PV modules are mounted on a passively controlled tracking structure and tilted at
55° for maximum winter performance. Sunlight resistant USE wire is used to
interconnect the modules. A switch box was attached to the pole and the linear current
booster was installed in the box. The pump was attached to 2-inch plastic pipe and
installed in the 3-inch bore hole. A float switch was installed near the top of the
holding tank and the control cables are protected from damage by conduit. The system
was grounded to the well casing using a short length of No. 6 stranded copper wire.
Worksheet 1-Calculate Water Pumping Load
4
Worksheet 2-Pumped Water and Pumping Rate
Controller Specifications
5
This linear current booster was used between the pump and the PV array to provide a
better match between source and load.
Switches and Protection Components
6
DC Wire Sizing Specifications
The wiring diagram for this system is represented below.
