Reducing Energy Costs on Vegetable Farms Michael Bomford, PhD Kentucky State University College of Agriculture, Food Science & Sustainable Systems
Quadrillion BTUs 3 Total Energy Consumed on US Farms, 1965-2002 2 Natural gas Electricity LP gas Diesel 1 Gasoline 0 Fertilizers and pesticides 1965 1970 1975 1980 1985 1990 1995 2000 John Miranowski, Iowa State University
Low input farming techniques Conservation tillage Cover cropping Organic Integrated Pest Management
Changes that are (almost) free Gear up, throttle down Lower RPM is more fuel efficient Don t overload the engine Routine machinery maintenance Tire pressure Lubrication Clean filters and fluids Appropriate ballast to reduce slipping Machinery sized for the job
Inexpensive changes (<$100) Insulate water heater Only necessary for older (>5 years) water heaters. Does it feel warm to touch? Costs $15-$35 Payback less than a year Replace incandescent bulbs with compact fluorescent Cuts energy for lighting by 75% Cuts lighting cost in half
Inexpensive changes (<$100) Weatherize buildings Homes, barns, sheds, greenhouses Caulking, weather stripping Can reduce heat loss by one-third See www.eere.energy.gov/weatherization Caution! Air flow / ventilation is crucial to animal and plant health
Energy Efficient Fans Install energy efficient fans High volume, low speed fans more efficient than high speed fans Large diameter more efficient than small diameter Straight blades more efficient than cloverleaf Discharge cone increases efficiency Clean and lubricate fans Open doors, windows & vents when fans operating
Walk-in Cooler CoolBot costs $300 and allows use of offthe-shelf air conditioner and well-insulated room for walk-in cooler. Cut up-front installation costs by 75% Cut energy costs in half Not suitable for cooler that is opened frequently Cools more slowly than conventional cooler.
Replace Greenhouse Thermostats with Environmental Controllers Controls heating, cooling and humidity control systems Avoids simultaneous heating and cooling Allows night set back and temperature flexibility to work with outdoor environment Less energy, better crops Controllers cost $250+
Energy Efficient Heating Radiant heat for homes, workshops In-floor warm water pipes Heat surfaces, not air Comfort at lower temperature Heat more evenly distributed System costs $3-$4 per square foot New construction less expensive than retrofitting Possible to integrate with solar hot water heat
Greenhouse Heating Efficient Furnaces Pay Back Quickly Gravityvented Powervented Separated combustion MSRP ($) 2083 2169 3131 5743 Extra cost ($) 0 86 1048 3660 Thermal efficiency 80% 80% 82% 93% Seasonal efficiency 65% 78% 80% 91% Fuel (gallons) 2499 2082 2030 1785 Fuel saving (%) 0 16 19 29 Cost saving ($)* 0 1209 1360 2070 Payback (months) 0 1 9 21 *Assumes liquid propane fuel at $2.90 per gallon All other cost, efficiency, and consumption estimates from: Sanford, Scott. 2006. Greenhouse Unit Heaters: Types, Placement, and Efficiency. University of Wisconsin Extension Bulletin A3784-15 Condensing Combustion
Alternative Heating Fuels Can Save $ Online calculator at Hearth.com
Wood Boiler for Greenhouse and Home Heat
Passive solar -- High tunnels and row covers instead of heated greenhouses
Dec. 15, 2009, Smiths Grove, KY. Paul and Alison Wieidger
March 24, 2009, Shelbyville, KY. Ken Waters
Tomato season Green- house Field Fall high tunnel Transplant production Growth Harvest Spring high tunnel D J F M A M J J A S O N D
Sanjun Gu. 1998
Chinese-style solar greenhouse Zhang & Boris, 2007. University of Manitoba & Manitoba Hydro.
Eighteen raised beds, 6 x 36 Five mulch treatments in four replicate blocks: Bare control Black Plastic Silver Plastic Black Landscape Fabric (2 reps only) Hay
Varieties tested Six heirloom varieties randomly assigned to six 6 sub-plots in each bed Green Zebra Pruden s Purple Red Pear Rose de Berne Yellow Pear Yellow Perfection Transplanted at 6 weeks on June 22, 2011 Plants spaced 18 apart
Monitoring Soil moisture June 22 Sept. 29 Field Scout TDR-300 Soil temperature June 30 Aug. 10 Temp. recorded hourly 2 cm below soil surface Probes attached to CR-1000 datalogger Yield All fruit harvested Sept. 16 and Sept. 29 Counted, graded & weighed
Results Soil Temperature Temperature lowest at sunrise; highest mid-afternoon Hay moderates daily temperature flux Black plastic maintains warmer temperature throughout day Temp. ( C) 36 34 32 30 28 26 Bare Black Fabric Hay Silver 24
Results Soil Moisture Higher soil moisture under landscape fabric than other mulches
Yields higher with hay mulch than with no mulch or landscape fabric Results - Yield
Resources A Farmer s Guide to Energy Self Reliance (Vermont Law School Institute for Energy and the Environment, 2008) Handbook: How to Decrease Consumption and Increase Profits Report: A Guide to Using Energy Efficiency, Biomass, and Renewable Energy on the Farm extension.org Sustainable Ag Energy Community of Practice (www.extension.org/ag_energy)
Contact: Michael Bomford 502-597-5752 Michael.Bomford@KYSU.edu Learn more: EnergyFarms.wordpress.com Organic.KYSU.edu Thanks to Tony Silvernail Jon Cambron Joni Thompson Mike Ward KSU Farm crew CASS & SEED programs Post Carbon Institute Teferi Tsegaye Kimberley Holmes