Balancing the Technology and
Economics of Farm Energy
Needs
Connecticut Farm Energy
Conference
Legislative Office Building
Hartford, Connecticut
November 5, 2013
Richard A. Peterson
NATC
A General Look at Energy use in
Agriculture
• Agriculture is Energy Dependent
• Primary Energy Drivers
– Electricity
– Diesel Fuel/Gasoline/Biofuels
– Fuel Oil/Natural Gas/Propane
– Solar/Wind/Methane/Biomass/Other
Renewables
Richard A. Peterson
NATC
Uses of Energy on Farms
•
•
•
•
•
•
•
•
•
•
Soil preparation
Planting
Crop Care
Commodity Harvest
Materials Handling/On Farm Processing
Environmental Control/Livestock Comfort
Storage Systems
Lighting
Heating
Transportation
Richard A. Peterson
NATC
Current Farm Energy
Consumption
• Direct energy – diesel, gasoline, LP gas,
natural gas, and electricity
• Indirect energy – fertilizers and pesticides
Richard A. Peterson
NATC
Breakdown of Farm Energy Use
Across the US
Total Energy Consumed in US Farms in 2002
Total = 1.7 Quadrillion BTUs
Natural Gas
4%
LP Gas
5%
Fertilizers
28%
Pesticides
6%
Gasoline
9%
Electricity
21%
Diesel
27%
Source: Prof. John Miranowski, Iowa State University
Richard A. Peterson
NATC
Direct Energy Expenditure per Dollar Expenditure and
Output in 2002: Major Crops
0. 058
Corn
0. 048
0. 053
0. 052
Soybean
0. 052
Cotton
0. 060
0. 070
0. 069
Wheat
0. 064
Rice
0. 092
0
0.02
0.04
0.06
0.08
0.1
Direct Energy Expenditure per dollar of
Total Expenditure
Direct Energy Expenditure per dollar
Output
Source: Prof. John Miranowski, Iowa State University
Richard A. Peterson
NATC
Direct Energy Expenditure per Dollar Expenditure and Output in
2002: Livestock
Hogs
Poultry
Dairy
0.032
0.017
0.028
0.023
0.040
0.038
Beef cattle
0.000
0.078
0.020
0.020
0.040
0.060
0.080
Direct Energy Expenditure per dollar of Total Expenditure
Direct Energy Expenditure per dollar Output
Source: Prof John Miranowski, Iowa State University
Richard A. Peterson
NATC
0.100
Direct Energy Expenditure per Dollar
Expenditure and Output in 2002:
Speciality Crops
0 .0 2 9
0 .0 2 1
Fruits/tree nuts
0 .0 3 1
0 .0 2 1
Vegetables
0 .0 3 4
0 .0 2 7
Nurseries
0
0.02
0.04
0.06
0.08
Direct Energy Expenditure per dollar of Total
Expenditure
Total Energy Expenditure per dollar output
Source: Prof John Miranowski, Iowa State University
Richard A. Peterson
NATC
0.1
Is Farm Energy Use
Increasing?
• Agricultural production is growing at an
average rate of 2% per year
• However, Energy inputs have remained
relatively flat over the last 30 years
• Farm operators have increased energy
efficiency
Richard A. Peterson
NATC
A quick look at Connecticut
agriculture
• Farm numbers have increased by 733
farms or 17.5% between 2002 and 2007.
• Farm acreage has increased 13.6% in that
same 5 year period
• However, the average acreage per farm is
down slightly
• The total value of farm commodities has
increased 17.2% between 2002 and 2007
Source: 2007 Census of Agriculture
Richard A. Peterson
NATC
The Top 9 of 25 Connecticut Ag
Commodities Represent more than
76% of total commodity value
•
•
•
•
•
•
•
•
•
Greenhouse/Nursery
Dairy
Chicken (eggs)
Aquaculture (clams & oysters)
Sweet Corn
Cattle and calves
Apples
Tobacco
Hay
Richard A. Peterson
44.2%
12.7%
8.7%
3.2%
2.0%
1.6%
1.4%
1.3%
1.1%
76.2%
NATC
How can Connecticut Farm
Operators Assess and Improve
Energy Efficiency?
• Get an energy audit (conducted by
agricultural professionals)
• Prioritize energy efficiency improvement
opportunities and set goals for
implementation
Richard A. Peterson
NATC
Why Conduct and Energy Audit?
• Energy audits provide a decision making tool to
help farm operators assess appropriate energy
conservation measures
• Energy audits provide a clear picture of a
farm’s energy use and the pattern of usage
by day and by season
• Audits are sometimes required as part of
energy related grant applications, such as the
USDA REAP grant program.
Richard A. Peterson
NATC
Thinking About a Renewable
Energy System?
An energy audit will provide valuable
information about energy use patterns on
your farm.
This information is very important as you
assess the economics of a renewable energy
system.
Richard A. Peterson
NATC
What are Energy Utilization
Indices?
• Energy Utilization Indices (EUIs) refer to the
amount of energy used to accomplish a
certain activity or process.
• EUIs for farms are stated in various ways:
• kWh/unit of production (cwt of milk, bu.
of grain)
• kWh/animal unit (cow, feeder pig, 100
chickens)
Richard A. Peterson
NATC
What Are Energy Conservation
Measures?
• Energy Conservation Measures refer to
equipment or operational measures that
will increase efficiency and save energy
Richard A. Peterson
NATC
The Value of Knowing EUIs
• Determining farm EUIs provides
benchmarking data related to similar farms in
the same region
• Having valid EUI data helps farm operators
prioritize energy efficiency upgrades
Richard A. Peterson
NATC
How Dairy Farms Use Energy
Information Gathered in an
Energy Audit
Northeast Agriculture Technology Corp.
Richard A. Peterson
Ithaca, NY
NATC
Major Energy use Functions on a
Dairy Farm
•
•
•
•
Milk Harvest*
Milk Cooling*
Lighting*
Air Circulation* and
Ventilation
• Washing and Water
Heating*
• Manure Handling
• Water Pumping
• Feed Handling
• Compressed Air
*Indicates uses where
significant
energy savings is
possible
Richard A. Peterson
NATC
WHERE IS ELECTRICITY USED
ON DAIRY FARMS?
Summary of electric energy use on a typical dairy farm
Electric water heating
5%
Miscellaneous
2%
Feeding equipment
3%
Milking
18%
Manure handling
5%
Lighting
17%
Milk cooling
26%
Ventilation
24%
Source: NATC, Ithaca, NY
Richard A. Peterson
NATC
Freestall vs. Tie Stall Operations
• Freestall operations
Feeding
Equipment
1%
Manure
Handling
4%
Misc.
1%
• Tie stall operations
Vacuum Pumps
17%
Feeding
Equipment
7%
Ventilation
21%
Ventilation
22%
Milk Cooling
27%
Lighting
26%
Lighting
17%
Electrical Water
Heating
2%
Richard A. Peterson
NATC
Manure
Handling
3%
Misc.
1%
Vacuum
Pumps
18%
Milk Cooling
23%
Electrical Water
Heating
10%
Renewable Energy Systems
Farms make a good fit
Richard A. Peterson
NATC
Key Issues of On-Farm Biogas
Generation
Richard A. Peterson
NATC
Anaerobic Digesters are
common worldwide
• There are 6 to 8 million low technology farmbased digesters used to provide biogas for
cooking and lighting
• The worldwide trend is toward larger, more
sophisticated systems with advanced
process control.
• The European Union countries are most
advanced in anaerobic digester applications
Richard A. Peterson
NATC
Farm Biogas Plants In The
European Union
Source: AD NETT, European Anaerobic Digester Network
Richard A. Peterson
NATC
Large Scale Agricultural AD
in Germany
Richard A. Peterson
NATC
Anaerobic Digesters in the US
• The first farm based digester was built at
McCabe Farms in 1972
• McCabe farms is a hog farm bordering the
Town of Mt Pleasant, IA
• Odor control was the driving reason for
building the digester
• Vertical plug flow/natural gas used to heat
• Still operational – all biogas is flared
Richard A. Peterson
NATC
Dairy Anaerobic Digesters
Elsewhere in the US
• Anaerobic digester interest among US
dairymen grew during the energy crisis of
the 1970s.
• Numerous digesters were built , but most
failed because of high operating costs, and
inadequate technology.
• There is a great resurgence of interest and
activity in many dairy states
Richard A. Peterson
NATC
Why Greater Interest in Manure
Digesters?
1. Need for controlling odor & managing waste (larger farms)
2. Higher prices for energy
3. Government (USDA) grants & loans
4. Media articles on farms producing green power
5. Increased cost for fertilizer (manure used as a substitute)
6. Firms looking to invest in biogas facilities & sell power
7. Carbon/renewable energy credits
Richard A. Peterson
NATC
Dealing With Volumes of Waste
1,200 lb. cow
produces her
own weight in
manure every
25 days*
150 lb. finishing pig
produces its own
weight in manure
every 15 days*
* 98 lbs of manure produced per day
A herd of 500 cows produces 49,000 lbs.
of manure per day
* 9.8 lbs of manure produced per day.
A herd of 500 finishing pigs produces 4,900 lbs.
of manure per day
Richard A. Peterson
NATC
Components of a Biogas System
Digester:
Consists of a closed
chamber or lagoon
Anaerobic microbes
(absence of oxygen)
To work correctly, it must
be managed. Consistent
input, keep within
acid/base tolerances, etc.
Richard A. Peterson
NATC
Components of a Biogas System
Solids Separator:
Squeezes out liquid to create a
dry bedding for cows.
Richard A. Peterson
NATC
Components of a Biogas System
Richard A. Peterson
NATC
Biogas Production System
Consider the additional expense,
number of moving parts,
maintenance and management
needed to turn gas into electricity.
Richard A. Peterson
NATC
Economics – Two New York Dairies
Sunny Knoll Dairy in New York
(1,400 cows)
Patterson Dairy in New York
(1,000 cows)
Digester:
Site Work
Engineering Design
Concrete Digester
Miscellaneous
Energy Conversion:
Engine-Generator
Elec., Controls, Plumb.
Biomass Use Bldg.
Family Labor
Digester:
$40,000
105,000
350,000
27,000
$350,000
145,000
30,000
Site Work
Engineering Design
Concrete Digester
Miscellaneous
Energy Conversion:
Engine-Generator
Elec., Controls, Plumb.
Biomass Use Bldg.
$7,500
2005 Constr. Cost $1,084,500
Family Labor
Solid-liquid separation
Building
Separator
2004 & 05 Constr. Cost
Richard A. Peterson
NATC
$62,723
99,532
495,930
31,893
$200,000
317,476
51,601
$68,553
127,775
53,147
$1,508,630
More Farm Renewable Energy
Opportunities
• Solar and Wind
• Biomass Production
• Biofuels
Richard A. Peterson
NATC
Gary Menard Dairy Farm
Mooers, NY
A 12.6 kW
Solar Photovoltaic System
With Zomeworks® Trackers
Richard A. Peterson
NATC
Cost Details
Menard Solar System
Total Cost (with tracker)
NYSERDA Incentive
USDA Grant
Menard Cost
Cost/kWh (34 months)
$124,647
$ 50,400
$ 31,161
$ 43,086
$ 0.41/kWh
Note: Solar tracking system can increase
annual output by up to 40%.
Richard A. Peterson
NATC
A 5.5 kW solar system
with NOVAR® Tracker
Currently producing 50%
more than a similar
system with a fixed array.
Richard A. Peterson
NATC
Lifetime Output and Economics
Shows lifetime output
since May 2006 
2006
2007
2008
2009
10 kW
Consistently generates approx. 7,000 kWh per year
Value:
7,000 kWh x $.09/kWh = $630 per year
Simple payback:
Installed cost = $50,000
With 30% tax credit, drops to $35,000
Yearly output = $630 worth of energy
Lessons Learned:
 Inverter destroyed by lightning
 Output slightly less than ratings
Takes 55.5 years to pay off 
 Cost of elec. generated = 74 cents/kWh
Richard A. Peterson
NATC
Summary
• Farms are energy intensive
• Energy Conservation and Efficiency
Improvements are a logical first step in a
long range energy management plan
• Renewable energy systems are compatible
with farm operations
• Few renewable energy systems are
economically feasible without incentives
Richard A. Peterson
NATC
Summary
• Renewable energy systems on farms should be
considered only after all practical energy efficiency
upgrades and energy conservation measures have
been adopted
• Reducing farm load on rural electric distribution
systems is beneficial to utilities and customers alike
• Renewable energy systems producing electricity on
farms can reduce stress on rural distribution lines
• The economics of renewable energy systems will
improve over time.
Richard A. Peterson
NATC
Thank you for your time.
Richard A. Peterson
NATC