Aquaponics Energy Efficiency Bethany Reinholtz Agriculture Energy Advisor
Overview Focus on Energy Who are we? How can we help? Energy efficiency options Funding opportunities
What is Focus on Energy? Wisconsin utilities statewide program for energy efficiency and renewable energy.
What is Focus on Energy? A partnership of all of Wisconsin s investorand municipally-owned utilities, as well as many electric cooperatives One statewide energy efficiency and renewable energy program rather than many, separate programs
What Does Focus on Energy Do? Helps Wisconsin residents and businesses implement energy-saving projects Offers unbiased information and technical assistance to participating utilities electric and/or natural gas customers Provides cash incentives for energy-saving projects that would not occur otherwise
Financial Incentives Energy efficiency Lighting Commercial Refrigeration Food Service HVAC Motors and Drives Geothermal Agriculture
Greenhouse Energy Breakdown Besides labor, energy bills = largest cost for greenhouse 70-80% Heating 10-20% Electricity Energy usage varies largely by the purpose of a greenhouse
Energy Efficiency Glazing material Thermal curtain Insulation Lighting Controls Heating options VFD s Ventilation
Glazing Materials Typical glazing materials Glass Fiberglass reinforced plastic Polyethylene film Acrylic Polycarbonate
Glazing Material Comparison Material % Light Transmission PAR Conduction Heat Loss U-Value Estimated Life Flammability Single Glass 88-93 1.1 25+ None Double, Insulated Glass 75-80 0.7 25+ None Single Acrylic 93 1.1 20+ High Double Acrylic 87 0.6 20+ High Single Polycarbonate 91-94 1.1 10-15 Low Double Polycarbonate 78-83 0.65 10-20 Low Triple Polycarbonate 76-78 0.5 10-20 Low Single Reinforced Fiberglass 90 1.2 10-15 High Single Polyethylene 87 1.2 3-4 Double Polyethylene 78 0.7 3-4 Double, IR Polyethylene 78 0.5 3-4 Source: NRAES-3 2001 Revision
Thermal Curtains 80-85% of greenhouse heating at night Reduces night heating up to 70% Must be sealed to prevent chimney effect Double as shade system Automated curtains expensive for seasonal growers Manual curtains lower cost
Thermal Curtains Issues Plants hanging from rafters Irrigation hanging from rafters Heating pipes Poly tubes Unit heaters Gable, roof vents, or open roof systems Fully drawn curtain will restrict summer air flow
Perimeter Insulation Existing buildings: install at base of slab, extending horizontally 8 New structures: install up to 2 inches along perimeter of building, up to a 4 depth Extend up to bench height Waterproof with vapor barrier Decrease heat loss from base by up to 75%
Environmental Controls Don t ventilate and heat at the same time Can increase greenhouse efficiency by 3% Can be programmed to provide optimal conditions Payback two-five years
Efficient Heating Boilers High efficiency water heaters High efficiency unit heaters
Water Heating Install high efficiency natural gas, LP, or biomass boiler Ex. 80 gallons water from 60 F to 135 F Electric =$1.47 [$0.10/kWh] LP =$1.28 [$2.00/gallon] Pellets =$0.83 [$185/ton] NG =$0.70 [$1.10/therm]
Boiler Tune-Ups Can reduce your boiler s gas consumption by 10% and increase output saving you energy and money Save on costly emergency outages and repairs Extend the life of your heating equipment
Root Zone Heating Often via radiant heating in raft system Lower heating costs of 20-25% Study: 7% increased yields for tomatoes Forced air under bench distribution, not as cost effective as hot water Reductions in air temperatures up to 15 F Happy roots = happy plants
Unit Heaters Low cost Easy installation HE models available Heat distribution location will affect heating costs
Unit Heater Efficiencies Type of heater TE SE Gravity vent heaters 80% ~65% Power vent heaters 80% ~78% Separated combustion 82% ~80% Condensing unit heater 93% ~91% Thermal efficiency (TE): combustion and heat transfer efficiency Seasonal efficiency (SE): includes TE plus heat loss out exhaust vents when heater is idle Gas-Fired Unit Heaters: A guide to greenhouse heating strategies, Catalog 10 115, Modine Mfg., September 1996 High-Efficiency Condensing Gas-Fired Separated Combustion Unit Heaters, Catalog 6-170, Modine Mfg., July 2009
Pumps and Motors HE or NEMA premium motors Motors <1 hp 40-80% efficient Aeration pond using two, 1 hp 50% efficient motors consume $2600 of energy per year Single 2 hp 80% efficient motor will consume $1633 of energy per year Smaller inefficient motors require more ventilation for cooling of motor
VSD s for pumps and motors Can be staged to trigger pumps to operate at a lower speed when needed or stage other pumps to come on-line as needed Ex: Aerating 20 indoor tanks with 2-1 hp motors can utilize the VSD system so that if only 5 tanks need aeration, 1 motor will operate at 50% capacity. If 10 tanks need aeration, 1 motor will operate at 100% capacity. These scenarios are programmed into the system and can be adjusted
Lighting
Types of Lighting High Intensity Discharge (HID) Reflectors Light Emitting Diodes (LEDs) Replace light fixtures if payback < 7 years
High Intensity Discharge (HID) High Pressure Sodium (HPS) Most efficient lamp for greenhouses Majority of light is near 700nm, wavelength that plants need Metal Halide Provide white/blue light, most similar to sunlight Install pulse start metal halide (PSMH) with electronic ballasts Combine with HPS lamps to produce full spectrum of light
Reflectors Help create uniform lighting and growth Many factors determine the efficiency, including shape and reflecting angle
Light Emitting Diodes (LEDs) Designed to only emit wavelength that plants need Better for smaller areas due to limited light output and high cost Light emitting plasma lamp (LEP)
Ventilation Natural Ventilation Ridge and Side Wall Vents Roll-up Sides Mechanical Ventilation Fans Louvers
Natural Ventilation No operating cost, but dependent on weather conditions Ridge and Side Wall Vents Relies on pressure differences Heated air escapes out top of ridge, cool air comes in side wall Roll-Up Sides mechanical and manual systems Greenhouse should have plenty of space around it for adequate air changes per hour
Mechanical Ventilation Fans Matching inlet and exhaust fans on opposite walls 1 air volume/minute is desirable Multispeed fans recommended Louvers Provide protection from weather when closed Intake louvers 1¼ times bigger than fan diameter Maintenance Can reduce a fan s energy cost by up to 20%
Aquaponics Efficiency Example Growing fancy lettuce, micro-greens, herbs and tilapia Water temperature 78 F Air temperature minimum 72 F Operation 24/7/365 NG cost = $0.90/therm Electric cost = $0.12/kWh
Efficiency Example Cont. Original Plan 8mm double polycarbonate Power vented unit heaters No thermal curtain Perimeter insulation No knee wall insulation No environmental controls Un-insulated fish house Standard NG water heater Efficiency Options 8mm triple polycarbonate side and end walls Condensing unit heater 65% shading thermal curtain 2 perimeter insulation 4 deep and 2 up knee wall Environmental controls Insulated fish house HE water heater
Annual Operating Costs Original Plan $22,268 Efficient Option $10,979 Cost savings = $11,289 Increased project cost: $31,800.00 Simple Payback: 2.8 years Potential Focus on Energy Incentives: $6,214 Simple Payback after Incentives: 2.3 years
Other Funding Programs USDA REAP program State Energy Programs Utility programs NRCS EQIP AgEMP CAP 122 and SPEC 374 www.dsireusa.org
Questions?
Contact Information Bethany Reinholtz, Agriculture Energy Advisor 608.354.0188 or 920.246.8453 bethany.reinholtz@gdsassociates.com Focus on Energy 800.762.7077 www.focusonenergy.com