1. Solar Water Heating Basics
Progress Energy Florida
Solar Water Heater Incentive Program
Colleen Kettles
Florida Solar Energy Research & Education Foundation (FlaSEREF)

2. Solar Water Heating Basics
How It Works
How Much Energy It Saves
How It Helps the Environment
How To Purchase
How Much It Costs
What Incentives Are Available

3. Types of Systems “Active” System Direct Pumped Indirect Pumped
Water is the collector fluid
Freeze protection provided by drain-back tank or freeze valves
Indirect Pumped
Anti-freeze is the collector fluid
Heat exchanger utilized within storage tank

4. Active Solar Water Heater

5. Active Solar Water Heater Direct Pumped
Water in the collector is heated by the sun. The differential controller

6. Active Solar Water Heater Direct PV Pumped

7. Active Solar Water Heater Indirect Pumped

8. The Collector Active Systems Use “flat-plate” collector
Insulated box with ½” copper piping integrated into a black absorber and glass cover
Fluid is water or anti-freeze
Designed to reach temperatures as high as 160° F

9. The Storage Tank Active System
Specially designed, heavily insulated tank (R value of 16 or greater)
Sizes range from 52 to 120 gallons for residential applications
Has only a top electric element
In a system using antifreeze, the tank will have an internal heat exchanger

10. Balance of System Components
Active System
Pump (ac or dc)
Differential Controller, or
Photovoltaic Panel
Assorted valves and vents
Copper Piping
Insulation

11. Types of Systems “Passive” System Integral Collector Storage
Collector provides additional water storage
No moving parts

12. Passive Solar Water Heater Integral Collector Storage

13. Passive Solar Water Heater Integral Collector Storage

14. The Collector Integral Collector Storage (ICS)
The collector is also the storage medium
Insulated box with 4” copper tubing welded together to serve as the absorber
Glass cover
Fluid is water
Designed to reach temperatures as high as 160° F

15. The Storage Tank Integral Collector Storage (ICS)
Collector provides ½ of the storage (32-50 gallons)
Existing or conventional tank provides the balance of storage

16. Balance of System Components
ICS System
Assorted valves and vents
Anti-scald valve (optional)
Copper piping
Insulation

17. Types of Systems “Passive System” Thermosiphon
Tank is roof mounted above collector
Uses flat plate collector
No moving parts
Reminiscent of early solar systems

18. Early Thermosiphon Solar Water Heater

19. Thermosiphon System

20. Passive Solar Water Heater Thermosiphon System

21. The Collector Thermosiphon System Uses “flat-plate” collector
Insulated box with ½” copper piping integrated into a black absorber and glass cover
Fluid is water or anti-freeze
Designed to reach temperatures as high as 160° F

22. The Storage Tank Thermosiphon System
The storage tank is specially designed to be mounted on the roof above the collector
An auxiliary tank with electric element is installed in the home

23. Balance of System Components
Thermosiphon System
Assorted vents and valves
Copper piping
Insulation

24. Household Hot Water Use
15% – 20% of total household energy consumption
Daily usage is 20 gallons each per day for the first two occupants; 15 gallons per day for each additional occupant
Example: Four person household will use 70 gallons of hot water and will need 80 gallons of storage

25. Collector BTU Ratings /Solar Fraction
Central Florida ambient water temperature is 72 degrees
Solar fraction is the proportion of hot water provided by the solar system
Optimal solar fraction is 70% and is based upon annual performance

26. Collector Btu Ratings /Solar Fraction
38,000 Btus will be needed to raise 80 gallons of cold water to 122 degrees
A 32 square foot ICS system is rated at 28,700 Btu/day and will provide a 77% solar fraction
A 40 square foot active collector is rated at 34,400 Btu/day and will provide a 92% solar fraction

27. Savings
The kWh equivalent of 38,000 Btu/day is kWh per day x 365 days = 4,063 kWh/year (electric load)
A solar fraction of 70 will offset 2,844 kWh
A solar fraction of 77 (28,700 Btu/day) = 8.4 kWh/day x 365 days, saves (or produces) 3,066 kWh/year
A solar fraction of 92 (34,400 Btu/day) = 10 kWh/day x 365 days, saves (or produces) 3,650 kWh/year

28. Savings At an average residential rate of $.115 per kWh:
A solar fraction of 70 will save $325/year
A solar fraction of 77 will save $350/year
A solar fraction of 92 will save $420/year

29. Back-up Hot Water
All solar water heaters will have a conventional energy back-up
No consumer action is required to activate the back-up
Back-up is needed for periods of excessive hot water use or inadequate solar resource

30. How It Helps the Environment
Emission Reductions (One Solar Water Heater Saves Annually)
Carbon Dioxide (5,000 lb)
Sulfur Dioxide (20 lb)
Nitrogen Oxide (12 lb)
Renewable Energy Credits
The “environmental attributes” of solar energy are a commodity

31. How to Purchase Contact reputable solar companies
Verify contractor licenses
Voice:
Solar contractor (CV)
Specialty solar (CW)
Plumbing contractor (CF)
Local solar license (RX)

32. How to Purchase Get more than one estimate, and get them in writing
Avoid high pressure sales tactics
Compare system types, sizes, prices and warranties
Ask for FSEC system certification
Ask for local references

33. How to Purchase
A local building permit should be obtained prior to installation (although some jurisdictions no longer require)
Contractor, not the homeowner, is responsible for the permit
If in doubt, homeowner should contact the local building department
Deed restricted communities will typically require prior approval (which cannot be denied)

34. How Much It Costs
Cost of a system varies depending upon the type of system and the size of system
Prices range from $3,000 to $5,000 in general
Rising material costs and the cost of doing business (gasoline, insurance, etc.) have resulted in price increases

35. Financial Incentives
Incentives are designed to lower the cost to the consumer
Sales Tax Exemption (6-7%)
Florida Solar Rebate ($500)
Progress Energy Rebate ($450)
Federal Tax Credit (30% with cap of $2,000)

36. Interaction of Incentives
Rebates should be deducted from the cost of the system before the federal tax credit is calculated
IRS has not issued regulations under this tax credit law
Exception would be if rebates are included as gross income

37. Interaction of Incentives
Example –
System cost: $4,000
State rebate: - $500
PEF rebate: - $450
Actual cost: $3,050
Federal tax credit: (.30 x 3,050) = $915
Net system cost: $2,135

38. Impact of Incentives on Consumer Savings
Net System Price of $2,135
Annual Savings of $325 = 6.5 year payback
Annual Savings of $350 = 6.1 year payback
Annual Savings of $420 = 5 year payback

39. For More Information THANK YOU www.flaseref.org www.flaseia.org
800-59SOLAR
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