Irrigation as if People
Mattered:
Energy Conservation
Lessons from Montana
Mike Morris, Ph.D.
Energy Program Project Leader
National Center for Appropriate Technology
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About NCAT
National non-profit organization, founded in 1976.
Main offices: Butte, MT, Fayetteville, AR, Davis, CA
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Programs: Sustainable Agriculture, Energy, Communities
This talk will
• Describe how Montana irrigators use energy.
• Offer lessons learned from five approaches to
energy conservation.
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Main Conclusions
• Irrigation efficiency is not just a technical problem,
but has intrinsic human and social dimensions.
• Irrigators welcome energy conservation but usually
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view it as a secondary consideration.
Montana Climate and Crops
• 10-20” rain and 100-150 frost-free days in
most areas.
• Top five crops by cash receipts:
wheat, barley, sugar beets, hay, potatoes.
• Half of irrigated acreage is hay, ¾ of hay
acreage is alfalfa.
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Irrigation Methods
• Only 5% of farmland (2 million acres) is irrigated.
• Of irrigated acreage, only 1/3 is sprinkler-irrigated.
• Half of sprinkler-irrigated acreage under pivots.
• 93% of irrigated acreage irrigated by surface water.
• 92% of irrigation pumps electric-powered.
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Water Availability
• Most irrigators pay nothing for water.
• Chronic water shortages the rule, not the exception.
• Water law limits opportunities for conservation.
• Informal arrangements, peer pressure often more
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important than legal constraints.
Energy Costs
• Electric rates low by national standards, but sharp
increases in recent years.
• Average $14.68 - $23.41 per pump-irrigated acre.
• NorthWestern Energy 2003-4 irrigation rates:
$8.03 per kW peak demand and $.043 per kWh.8
2002 Crop Values per Acre
Potatoes $2,928
Alfalfa hay $315
All hay
$278
Wheat
$190
Sugar beets
Corn
Barley
Oats
$856
$296
$193
$151
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Average Irrigation Energy Cost as a
Percentage of Crop Value
Potatoes 0.7%
Alfalfa hay 7.4%
All hay
8.4%
Wheat 12.3%
Sugar beets 2.7%
Corn
7.9%
Barley
12.1%
Oats
15.5%
“It’s the crop, stupid.”
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Labor Cost and Availability
Average pivot irrigation project cost $67,264,
with energy savings of $1,271 per year.
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Five Approaches to Energy Conservation
1. Energy Audits
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NCAT Experience
• Over 400 irrigation energy audits since 1988.
• Currently offering no-cost energy audits to
NorthWestern Energy irrigation customers.
• Measure pressure, flow rate, electrical power
output; calculate pumping plant efficiency.
• Customer receives report with recommendations,
payback, power bill analysis, incentive offers.
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Most Common Energy-Saving
Recommendations from Audits
• Replace worn nozzles
• Repair leaks
• Correct motor overloading problems
• Rebuild pump and/or motor
• Replace pump and/or motor
• Correct discharge problems
• Correct suction problems
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Lessons Learned
• Audits are highly appreciated, sometimes
desperately needed.
• Labor intensive (average cost $672 per audit).
• Only about half of participants completed
recommended improvements within 1 year.
• Equipment improvements do not necessarily
lead to energy savings.
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2. Direct Financial Incentives
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NCAT Experience
• Administering cost-sharing program for
NorthWestern Energy irrigation customers.
Most common customer project proposals in 2003:
• Replace hand or wheel lines with pivots (15)
• Replace high-pressure pivot w/low-pressure (8)
• Use gravity to reduce horsepower requirements (3)
• Replace oversized or inefficient pumps (2)
• Install variable frequency drives (2)
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Lessons Learned
• Dollar for dollar, direct incentives save more
energy than audits.
• Evaluation criteria need to be carefully designed
for consistency and fairness.
• Working closely with local equipment dealers a
key to success.
• Gravity conversion is probably the biggest
energy conservation opportunity remaining in
Montana’s irrigation sector.
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3. Soil Moisture Monitoring
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The M. K. Hansen AM400 Soil Moisture Data Logger
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NCAT has helped install over 120 soil
moisture monitoring systems since 2000.
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Lessons Learned
• Pivot systems offer the best opportunities for
conservation through improved management.
• Poor management is common, but gross
overwatering is less frequent than expected.
Only 3-6 of 43 study fields clearly exceeded
annual alfalfa water requirements.
• Better water management should be promoted
primarily in terms of crop yield and crop health.
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4. Educational Publications
• In 2003 NCAT revised and reprinted the
Montana Irrigator’s Pocket Guide.
• NCAT has contracted with NRCS to produce a
national edition.
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5. Collaboration with Local Watershed Groups
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NCAT Experience
• Working with local groups in river valleys with
chronic water shortages: Big Hole, Blackfoot ,
Boulder, Jefferson, Ruby, and Shields.
• Goal is to help each group organize and run its own
irrigation efficiency program.
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Lessons Learned
• Learning in rural communities takes place by
imitation and word of mouth.
• Groups vary widely.
• Progress on irrigation management is most likely
to come from locally-based projects that enable
irrigators to experiment on their own and learn
from each other.
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For More Information
• NCAT: www.ncat.org 1-800-ASK-NCAT
• National Sustainable Agriculture Information
Service: www.attra.ncat.org 1-800-346-9140
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