Download - Solar Water Heating Basics
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Solar Water Heating Basics
Progress Energy Florida
Solar Water Heater Incentive Program
Colleen Kettles
Florida Solar Energy Research & EducationFoundation (FlaSEREF)
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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
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Types of SystemsActive System
Direct Pumped
Water is the collector fluid
Freeze protection provided by drain-back tankor freeze valves
Indirect Pumped Anti-freeze is the collector fluid
Heat exchanger utilized within storage tank
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Active Solar Water Heater
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Active Solar Water Heater
Direct Pumped
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Active Solar Water Heater
Direct PV Pumped
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Active Solar Water Heater
Indirect Pumped
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The Storage TankActive System
Specially designed, heavily insulated tank(R value of 16 or greater)
Sizes range from 52 to 120 gallons forresidential applications
Has only a top electric element In a system using antifreeze, the tank will
have an internal heat exchanger
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Balance of System Components
Active System
Pump (ac or dc)
Differential Controller, or
Photovoltaic Panel
Assorted valves and vents
Copper Piping
Insulation
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Types of SystemsPassive System
Integral Collector Storage Collector provides additional water
storage
No moving parts
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Passive Solar Water Heater
Integral Collector Storage
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Passive Solar Water Heater
Integral Collector Storage
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The CollectorIntegral Collector Storage (ICS)
The collector is also the storage medium
Insulated box with 4 copper tubingwelded together to serve as the absorber
Glass cover
Fluid is water Designed to reach temperatures as high as
160 F
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The Storage TankIntegral Collector Storage (ICS)
Collector provides of the storage (32-50gallons)
Existing or conventional tank provides thebalance of storage
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Balance of System Components
ICS System
Assorted valves and vents
Anti-scald valve (optional)
Copper piping
Insulation
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Types of SystemsPassive System
Thermosiphon Tank is roof mounted above collector
Uses flat plate collector
No moving parts
Reminiscent of early solar systems
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Early Thermosiphon Solar
Water Heater
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Thermosiphon System
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Passive Solar Water Heater
Thermosiphon System
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The CollectorThermosiphon System
Uses flat-plate collector
Insulated box with copper pipingintegrated into a black absorber and glasscover
Fluid is water or anti-freeze
Designed to reach temperatures as high as160 F
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The Storage TankThermosiphon System
The storage tank is specially designed tobe mounted on the roof above the collector
An auxiliary tank with electric element isinstalled in the home
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Balance of System Components
Thermosiphon System
Assorted vents and valves
Copper piping
Insulation
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Household Hot Water Use 15% 20% of total household energy
consumption
Daily usage is 20 gallons each per dayfor the first two occupants; 15 gallonsper day for each additional occupant
Example: Four person household willuse 70 gallons of hot water and willneed 80 gallons of storage
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Collector BTU Ratings
/Solar Fraction Central Florida ambient water
temperature is 72 degrees
Solar fraction is the proportion of hotwater provided by the solar system
Optimal solar fraction is 70% and is
based upon annual performance
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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 at28,700 Btu/day and will provide a 77%solar fraction
A 40 square foot active collector israted at 34,400 Btu/day and willprovide a 92% solar fraction
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SavingsThe kWh equivalent of 38,000 Btu/day is11.13 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) = 8.4kWh/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) 3,650kWh/year
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SavingsAt 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
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Back-up Hot Water All solar water heaters will have a
conventional energy back-up
No consumer action is required toactivate the back-up
Back-up is needed for periods of
excessive hot water use or inadequatesolar resource
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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
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How to Purchase Contact reputable solar companies
www.flaseia.org
www.findsolar.com Verify contractor licenses
www.myfloridalicense.com
Voice: 850-487-1395
Solar contractor (CV) Specialty solar (CW)
Plumbing contractor (CF)
Local solar license (RX)
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How to Purchase Get more than one estimate, and get
them in writing
Avoid high pressure sales tactics
Compare system types, sizes, pricesand warranties
Ask for FSEC system certification
Ask for local references
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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 bedenied)
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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 ofdoing business (gasoline, insurance,etc.) have resulted in price increases
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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)
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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 areincluded as gross income
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Interaction of IncentivesExample
System cost: $4,000
State rebate: - $500
PEF rebate: - $450
Actual cost: $3,050Federal tax credit: (.30 x 3,050) = $915
Net system cost: $2,135
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Impact of Incentives on
Consumer SavingsNet System Price of $2,135
Annual Savings of $325 = 6.5 yearpayback
Annual Savings of $350 = 6.1 yearpayback
Annual Savings of $420 = 5 yearpayback
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For More Information www.flaseref.org
www.flaseia.org
www.fsec.ucf.edu
www.floridaenergy.org
800-59SOLAR
THANK YOU