Odum’s Energy Ecology & Green Houses

Local and Ecological

Outline Odum Energy, Ecology

and Economics Food Supply Greenhouses Growth Systems Ecology of

Greenhouses Energy in Greenhouses

Heat Gain and Loss Energy Value Efficiency

Passive Solar Design Orientation

Recap: Importance of Growing Local

Living Building Examples

Odum’s Energy Ecology Growth Priming:

Favors economic vitality Quality Vs. Quantity

Reduction of subsidies Quality of Life

From steady state periods Net Output Richer than

Input Solar Conversion

Necessary Simpler Agriculture as a

Primary Solution

Applied to Food Supply Food = Basis for Society Quality of Energy:

Stability and Growth Vitality of Food Growth Materials

Quality of Life: More Time with People Application of Purpose

Food Supply Considerations Human Population

Estimated 9 billion in 2050 (6.6 billion in 2008) 2/3 Expected to be Urban Dwellers

Global Warming Influence

Food supply Agriculture systems Arable land

Influences Water Supply Needs to increase clean supply Needs to increase availability and distribution

A Look at Green Houses Human and Natural Ecology Combined Local Energy Capture and Storage

Input Energy Stored for Output Energy Use Local Energy Generation and Savings

Uses Natural Processes and Natural Storage/Blocking Carbon and GHG Neutrality: Possible! Community Based Designed

Based on need, and available resources Enhance Food Security Adaptable Efficient

Automation possible

Types of Growth Systems Mono Culture Polyculture Biodynamic Hydroponics Aquaculture Algae for Energy

Growth

Ecology of Green Houses Incorporate with Waste Streams or Algae

Culture for Nutrient Enhancement Create ‘Green Space’ in Office Space

Reduce Building Energy Needs Reduce Footprint of Greenhouses and Food

Supply

Reduce Nutrient Runoff Through Monitoring

Energy in Greenhouses Energy from our environments

Continuous and Renewed Solar, Organic, Natural Gas*, Water, Wind, Wood

Stored Coal and Fossil Fuels, Natural Gas*, Nuclear

In Ecology: Where continuous energy creates/generates stored energy Smart energy use is the lower energy ‘cost’ to produce the

same stored energy and/or energy output

70-80% Used for Heating; 10-15% for Electricity [2]

Heat Gain & Loss Conduction

Heat conducted through materials U-value – Btu/(hr-ºF-sq.ft.)

Convection Heat exchange between moving

fluid (air) and solid surfaces Radiation

Heat transfer between two bodies without direct contact or transport medium

Sunlight Air Leakage/Infiltration

Exchange of interior and exterior air

through small leaks and holes.

Increasing Energy Value Growth Versus and Towards Stability Reduce inefficiency of energy growth process

Reduce Dependence on Fuel subsidies Reduce Use of Non-Renewals Reduce Pollution Increase Output Recycling

Increase Efficiency of Current Systems Reduce outputs for maintenance and general operation.

Enhancing Efficiency Stand alone

Isolated growing conditions Include lots of plants to heat Natural ventilation

Opening Side Walls or Top Windows

1.7-1.8 – heat loss area to floor area (3000sq. ft.)

Materials selection Water Collection/ Indoor Storage Color Selection Orientation

Passive Solar Design[3]

Passive Solar Design (con’t)

Greenhouse: Passive Solar Design Thermal Mass

(BTU/sqft/Fo)

Brick 24

Concrete 35

Earth 20

Sand 22

Steel 59

Stone 35

Water 63

Wood 10.6Attached greenhouse:

2.5 gallons per sq. ft. of south facing glazing area for cool climates (4 month winters)2 gallons per sq. ft. of south facing glazing area for temperate climates (3 month winters)

1 gallon per sq. ft. of south facing glazing area for warmer climates (2 month winters)

Free standing greenhouse: 3 gallons per sq. ft. of south facing glazing area for cool climates (4 month winters)

2.5 gallons per sq. ft. of south facing glazing for temperate climates (3 month winters)2 gallon per sq. ft. of south facing glazing for warmer climates (2 month winters)

Sample R and U Values

Polycarbonate 6mm quad wall R = 1.79

Polycarbonate 8mm quad wall R = 2.13

Polycarbonate 16mm triple wall R = 2.5

Polycarbonate 8mm triple wall R = 2.0-2.1

Polycarbonate 8mm double wall R = 1.6

Acrylic double wall R = 1.82

Glass double layer R = 1.5 – 2.0

Glass double layer low-e R = 2.5

Glass triple layer 1 / 4 “ ( 0.6 cm) air space R = 2.13

Fiberglass glazing- single layer R = .83

Polyethylene Double 5mil film R = 1.5

Polyethylene Double 6mil film R = 1.7

Polyethylene single film R = 0.87

6 inches (15 cm) of fiberglass bat insulation R = 19.0

Polystyrene (styrofoam) 1 inch (2.5 cm) thick R = 4.0

Orientation East/West to Maximize Winter Sunlight Incorporate Cooling Sections for Air Flow Moveable Gutter Overhangs

[3][6]

Increase Energy Value of Food Grown in biodynamic, or polyculture systems Grow and Buy Organic Process By Hand Picked When Ripe Food Eat Fresh Soil Enhancement

External Greenhouse Example: Vertical Wall Green House Increased Food Supply Hydroponics Double-Skin Facades Reduce Maintenance

Provide Shade Air Treatment Evaporative

Cooling Reduced Costs

Mitigation Insulation

BioMachine: Buildings of Future Incorporate Automated Systems

Clean Air Enhance Nutrients Irrigation Supply and Water Management Local Harvesting

Solar Panels Solar Thermal Passive Heating and Cooling

Conclusions Human Ecological Incorporation Total Waste and Energy Stream

Considerations Reduced Need for Energy Increase Food Supply and Security Adaptability and Self Design

References[1] - HT Odum- Energy Ecology and Economics

[2] Sanford, Scott; Energy Conservation for Greenhouses; http://www.uwex.edu/energy/pubs/GreenhouseEC_SAREApril2010.pdf

[3] Sethi, V.P.; Survey and evaluation of heating technologies for worldwide agriculture greenhouse applications; 2010

[4] Sethi, V.P. ; Experimental and economic study of a greenhouse thermal control system using aquifer water; 2007

[5] Theodore Caplow; Vertically Integrated Greenhouse: Realizing the Ecological Benefits of Urban Food Production; Ecocity World Summit 2008 Proceedings; 2008

[6] David Roper; Solar Greenhouses; http://www.roperld.com/science/solargreenhouses.htm