This document discusses using solar energy to heat greenhouses at night for growing crops. It describes: 1. The problem of increasing costs of heating greenhouses with fossil fuels and the pollution it causes. 2. The solution of using solar energy absorption and storage techniques like polyethylene mulching, water tubes, and thermal screens to heat greenhouses at night without fossil fuels. 3. Experimental results showing the system successfully maintained temperatures above 16°C for growing basil, increased yields, and prevented leaf diseases compared to uncontrolled greenhouses.

1. Solar Energy for heating
greenhouses at night
The International CIPA Conference
Tel Aviv Israel, May 15- 17, 2012
David Shapiro
Maianot R&D Center

2. Funding and partners
Tzion Deko, Shahar Itshak, R&D Emeq Hamaayont
David Silverman, Extension service Ministry of Agriculture
Uri Adler, Plant Board, Itzhak esquire, Plant Board
Ran Dagan “DAGAN”
Yoram Sztyglic, Ginegar Plastic Products LTD

3. 0C
Temp
0
5
10
15
20
25
30
35
40
19-Dec-11
22-Dec-11
25-Dec-11
28-Dec-11
31-Dec-11
3-Jan-12
6-Jan-12
9-Jan-12
12-Jan-12
15-Jan-12
The problem
18-Jan-12
21-Jan-12
24-Jan-12
27-Jan-12
30-Jan-12
2-Feb-12
5-Feb-12
8-Feb-12
plant which needs temperature above 160C.
11-Feb-12
14-Feb-12
and basil is 40% of the group. Basil is a tropical
fresh herbs in the winter is a major export crop
17-Feb-12
20-Feb-12
23-Feb-12
26-Feb-12

4. 1. Increasing costs, decreasing income
• Dramatic increases in
oil prices in the past
three years
• The cost for heating
one hectare is
$100,000 per season!

5. Heating with fossil fuel (Crude oil)
compromise Wandering
leaf diseases
Low yield

6. 2. Pollution and greenhouse gases
Heating with crude oil is
a major contributor to
air pollution and release
of greenhouses gases
CO2 and Sulfur

7. The solution:
Sun, soil, water and polyethylene!
Solar energy
for heating
greenhouses

8. The basic principles
1. Absorption of the energy from the sun
(during the day).
2. Storing the energy and avoiding loses of
energy to the surroundings.
3. Using the energy at night.

9. Absorption and storage of energy from the sun
Water tubes
Clear
Polyethylene
mulching
Wetted soil

10. Temperature 0C
10
15
20
25
30
35
0
5
26/12/2011 12:00
27/12/2011 0:00
27/12/2011 12:00
28/12/2011 0:00
Time
28/12/2011 12:00
29/12/2011 0:00
Soil Temperature (4- 6 cm)
29/12/2011 12:00
7.7
21.7
30/12/2011 0:00
Outside
mulching
Greenhouses with

11. reducing loses of energy to the surroundings
Light transmission in PAR % ASTM D-1003 90
UV-transm. (300-380nm.) % " 0
Diffused light tr. in PAR % " 15
Thermicity (7-15mic.) % Internal FT-IR 87
Anti-Drip Yes
Thermal
IR TAVLIN Screen
C405
150 mic
Double
Air layer layer
for cover
insulation
Wetted soil

12. Using the energy at night.
IR

13. Horizontal water tubes,
Double layer of polyethylene sheets and mulching
IR BASIL C408 50 mic
Light transmission in PAR % ASTM D-1003 91
UV-transm. (300-380nm.) % " 80
Diffused light tr. in PAR % " 15
Thermicity (7-15mic.) % Internal FT-IR 60
Anti-Drip Yes
WATER TUBE CLEAR
C135 200 mic

14. 2 layers of PE sheets compared to one
IR photos
180C 140C

15. Vertical water tubes

16. Energy absorption in water

18. Basil after frost damage Jan. 13, 2008
Mulching, 2 layer
PE, thermal screen and
water tubes
Control

19. Improving energy absorption:
Orientation of the tunnel

20. THE ANGLE OF THE SUN ON THE
SHORTEST DAY OF THE YEAR
N S
α
β
α<β

21. Light Intensity (Micro Einstein)North South, East west
Orientation
Llight intensity 17/12/2008 12:00
outside
1400
1200
East West
North South
1000
light intensity
800
Llight intensity
600
400
200
0
OUT No 1 No 2 No 3 No 4 No 5 No 6 No 7 No 8 No 9
Tunnel No

22. 2009-10
Yield of basil Kg/1000m2
940
East- West
920
Soil
900
mulching
880 horizontal
water tubes,
Kg/1000 2
thermal
1000m
860
840
820 North-south
Soil
800
mulching
780 horizontal
water tubes,
760 thermal
740
screen
NO1 NO9
TUNEL NO

23. “Eden” Tunnel
N S
6m

24. “Eden” Tunnel
N S

25. Wall of Water
8m3

26. Wall of Water

27. Water Wall (black)

28. Water Wall (black)

29. Water wall

30. Water wall

31. Water wall

32. Yield
600
Water Wall
500
400
Kg1000 m2
1000
Control
Kg/1000m2
300
200
100
0
1 2 3 4 5 6 7 8 9 10 11 12

33. Prevention of leaf diseases
Botrytis and sclerotinia

34. Improving The absorption of the water
tubes

35. Improving The absorption of the water
tubes

36. Clear water
tubes
Black water
tubes

37. Improving The absorption of the water
tubes

38. Improving The absorption of the water
tubes

39. Take home message ….
• We have a simple sustainable non polluting no emissions system for
growing summer crops in the winter by using only solar energy.
• It’s possible to grow basil crops in the winter in Israel by using: PE
mulching, water tubes, thermal screens, double layers of PE
covering material.
• The best results were achieved by using a wall of water tubes
standing on the north side of the tunnels
• Orientating the tunnels east-west has a considerable advantage
over north-south orientated tunnels
• It’s possible to grow Basil without winter diseases without any
spraying
• Depending on climate conditions there is a possibility to use only
part of the facilities and get good results

40. The most complicated thing is
to do a simple thing
David Shapiro
dashap43@gmail.com