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Northwest Rural Public Power District
Voluntary Customer Premium Payments
Nebraska | NE
Off-Grid Applications (communications, lighting, pumping, etc)
The Northwest Rural Public Power District (NRPPD) offers PV Water Pumping systems for livestock to customers as an alternative to expensive line extensions.
A common livelihood in Nebraska is cattle ranching and farming. Cattle are regularly rotated from one pasture to another, with remote wells for water needs. The wells are typically not in the vicinity of the electric grid and some have traditionally been powered by windmills. However, wind speeds decline during the summer months. As a low-cost alternative to expensive line extensions, NRPPD rents, leases and/or sells PV water pumping systems to interested customers.
For rentals, the utility owns the PV panels, which are mounted to a trailer that can be moved from well to well in conjunction with the cattle rotation. The customer is responsible for acquiring and maintaining the remaining equipment, which includes the storage tank, water pump motor, water pipes, motor housing, etc. The purchase cost for the PV system varies by size, a 150W system is sold for roughly $1,500 (upfront cost), 300W system is a little over $4,000 and a 1,024W system has an upfront cost of $11,500.
The first system rented out by the utility was in 1990. To date nine systems have been sold and twenty systems are being leased. The systems come in three sizes: 100-200 watts, 300-400 watts, and 800-1200 watts. PV sizing factors include the amount of water required and how far - both vertically and horizontally - the water must be pumped, storage tank size and quality and if batteries are required to extend pumping time. For example, a 336 watt system without battery back-up is capable of pumping 4,500 gallons of water per day from a 40 feet deep well, which waters roughly 80 cattle.
The expected annual maintenance cost for these systems is about 4% of the initial system cost with an average lifetime of 6.3 years.
General Project Description: http://www.nrppd.com/cust_service/products/photovoltaic.html
PV Water Pumping paper: http://www.usda.gov/rus/electric/engineering/sem2002/skinner.htm