2. LEARNING TARGET: I can design a more efficient solar energy collector.
Feb 28 / Act D 69
Solar Heating
LEARNING TARGET: I can design a more efficient solar energy collector.
CH Q
What is the efficiency of a solar energy collector?
VOCAB:
Calories; efficiency; passive solar heating

3. energy needed to raise 1g (or mL) of water 1°C Calories
Efficiency
Passive solar heating
ratio of energy released compared to energy going into system
Sun thermal energy transfer without machines

4. PROCEDURE: Read on pg. D 89-93 and summarize
PROCEDURE AND DATA
MATERIALS:
PROCEDURE: Read on pg. D and summarize
DATA: WS Solar Heating
WS Improved Solar Heating Design
Next slide – lab hints

5. DO NOT RUN / CONNECT THE PUMP WITHOUT WATER TO GO THROUGH IT !
DAY 1
*change use 200mL water
Part A: Gathering the Data
Part B: Calculating Efficiency
WARNING!
DO NOT RUN / CONNECT THE PUMP WITHOUT WATER TO GO THROUGH IT !
If pump doesn't work – pull the hose out just a little bit to avoid hitting the propeller inside.
Next Slide – lab set up

6. DAY 1: Set-Up

7. TIME (min)
TEMP: tested ( C )
TEMPERATURE: class control ( C ) 21 1
21  2 3 4 22 5
 22 6 7 8 9
 23 10 11 12 13
 24 14 15

8. PART B: Calculate efficiency of Day 1.... Check your math!
200 A. B.
∏r2 / 2 = cm2 C. B. A. C.
Turn in paper after going over it!!!!

9. 11 degrees C X 100 mL = 1,100 calories
Energy transferred to water (calories)
11 degrees C X 100 mL = 1,100 calories
Area of solar heater (cm2)
180 cm2
Energy transferred to the tubing (calories)
1.5 calories / cm2 / min X 180cm2 X 15 min = 4,050 calories
Efficiency of heating system (%)
 1,100 Calories ,050 calories X 100%
= 27 %

10. FLOWER SOLAR CELL

11. DAY 2
Part C: Improved Solar Heating Design

12. DAY 2
Part C: Improved Solar Heating Design
Possible Ideas!! Record on WS 69.2
heat for longer than 15mins
dark area around tube “coil”
reduce water amount
increase light intensity (Watts or less distance)

13. DO LAB!!! Follow correct protocol. – GET LAB READY Quickly and quietly
You did this last class, however this lab is to make improvements.
You will have 25 minutes to Set up, Collect your data, and Clean up

14. NOW!!!! Calculate efficiency of Day 2.... Check your math!
200 A. B.
∏r2 / 2 = cm2 C. B. A. C.
Turn in paper after going over it!!!!

15. increases POST DISCUSSION
Relationships between your data and calculations:
The longer the water circulates through the system, the …
As the temperature of the water increases, the rate of change…
Warmer it becomes. (The temp increases)
Slows down.
- As intensity increases (closer distance) efficiency…
increases

16. ANALYSIS
- Discuss and answer Q 2 on pg. D 93
ANS CHALLENGE Q
What is the efficiency of a solar energy collector? A:
~25%, but with modification up to 30%?
HOMEWORK
Catch up on Journals – Complete Analysis Q’s