ENVIRO-NEWS: ARS Publishes Guide for Remote Solar Water Pumps

---------- Forwarded message ----------
From: "Makuch, Joseph" <Joseph.Makuch@ars.usda.gov>
Date: Mar 26, 2010 9:37 AM
Subject: [ENVIRO-NEWS] ARS Publishes Guide for Remote Solar Water Pumps
To: <Enviro-News@nal.usda.gov>

-----Original Message-----
From: ARS News Service [mailto:NewsService@ars.usda.gov]
Sent: Friday, March 26, 2010 8:25 AM
Subject: ARS Publishes Guide for Remote Solar Water Pumps

STORY LEAD:
ARS Publishes Guide for Remote Solar Water Pumps
___________________________________________

ARS News Service
Agricultural Research Service, USDA
Don Comis, (301) 504-1625, donald.comis@ars.usda.gov
March 26, 2010
--View this report online, plus photos and related stories, at
www.ars.usda.gov/is/pr
--Follow us on Twitter at http://twitter.com/ARSInformation
___________________________________________

A guide to choosing a solar water pump for remote (off-grid)
applications has been published by Agricultural Research Service (ARS)
scientists.

For this guide, agricultural engineer Brian Vick and colleagues drew on
the ARS Conservation and Production Research Laboratory's 31 years of
testing stand-alone water pumps. The laboratory is located near
Bushland, Texas.

Vick found that for pumps with motors rated less than 1,500 watts, solar
is usually the best choice. With current technology and costs, wind
power or a hybrid wind/solar pump is usually best for power needs of
1,500 watts or more.

Vick and colleagues tested three major pump types: diaphragm, helical
and centrifugal. Diaphragm and helical pumps can maintain almost the
same maximum flow rate over a large range of pumping depths. Because
maximum flow rate increases with increasing power, centrifugal pumps can
pump more water than diaphragm or helical pumps, although a photovoltaic
(PV) array rated at a higher power may be required, especially at deeper
pumping depths.

Powered with a 160-watt PV array, most diaphragm pumps sold today can
draw sufficient water from wells 100 feet deep or less to supply 75 head
of cattle. Some recently designed diaphragm pumps can draw from as deep
as 230 feet, but can only supply sufficient quantities of water for 30
head of cattle.

ARS research indicates that if more water is needed or a deeper well is
required, a pump type other than a diaphragm--and a PV array of more
than 160 watts--is recommended.

The researchers also recommend using a controller on all pumps. For
irrigation, they recommend the centrifugal pump with a hybrid wind/solar
power system.

Their guide offers case studies in the Bushland area, where wells are
more than 230 feet deep. One example is a four-person household, for
which they recommend a helical pump powered by a 500-watt PV array. To
supply water to 150 head of beef cattle, they would use a helical pump
powered by a 640 watt PV array.

The guide, published by the American Solar Energy Society in 2009, is
available online at http://www.cprl.ars.usda.gov/REMM_Publications.htm

ARS is the principal intramural scientific research agency in the U.S.
Department of Agriculture.
___________________________________________

USDA is an equal opportunity provider, employer and lender.  To file a
complaint of discrimination, write:  USDA, Director, Office of Civil
Rights, 1400 Independence Ave., S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice), or (202) 720-6382 (TDD).
___________________________________________

This is one of the news reports that ARS Information distributes to
subscribers on weekdays.
Send feedback and questions to the ARS News Service at
NewsService@ars.usda.gov.
[deletions]
__________________________________________
ARS News Service, Information Staff, Agricultural Research Service
5601 Sunnyside Ave., Room 1-2251, Beltsville MD 20705-5128
NewsService@ars.usda.gov | www.ars.usda.gov/news
Phone (301) 504-1636 | fax (301) 504-1486

***********************************************
Enviro-News is a service of the Water Quality
Information Center at the National Agricultural
Library.  The center's Web site is at
http://www.nal.usda.gov/wqic/.

The Enviro-News list facilitates information exchange.
Inclusion of an item in Enviro-News does not imply
United States Department of Agriculture(USDA) agreement,
nor does USDA attest to the accuracy or completeness of
the item. See
http://www.nal.usda.gov/wqic/environews.shtml#disclaimer
You can contact the list owner at
owner-Enviro-News@ars.usda.gov.
***********************************************