Q: What is a solar water heater?
A solar water heater uses the sun's energy rather than electricity or gas to heat water, thus reducing your monthly utility bill. When installed properly, solar water heaters are more economical over the life of the system than heating water with electricity, dedicated heat pumps, heat recovery units or propane.
In Florida, three types of solar systems are used: pumped, integral collector storage (ICS), and thermo-siphon. The direct circulation system (see Figure 1, page 2) circulates potable water from the water storage tank through one or more collectors and back into the tank. The solar collector is the main component of the solar system. It is usually a metal box with insulation and a black absorber plate that collects solar radiation and heats the water. The circulating pump is regulated by either an electronic controller, a common appliance timer, or a photovoltaic (PV) panel.
In integral collector storage systems, the solar water storage system is built into the collector. The potable water in the collector unit is heated by the sun and delivered by city or well water pressure to an auxiliary tank (which contains non-solar back-up heating) or directly to the point of use.
A thermosiphon solar water heating system has a tank mounted above the collector (normally on the roof) to provide a natural gravity flow of water. Hot water rises through piping in the collector, which is mounted below the tank; heavier cold water sinks to the lowest point in the system (the collector), displacing the lighter hot water which rises to the tank.
The ICS and thermosiphon systems are simple since they use no pumps or controllers and water always flows through the collector.
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Q: How does a direct circulation solar system work?
As sunshine strikes the collector, the water inside it is heated. If the circulating pump is regulated by a PV panel, the pump starts turning as the PV panel is activated by the same sunshine. This direct current (DC) motor pump moves water from the tank through the collector and back to the tank. As the sun's intensity changes throughout the day, the circulating pump also changes its speed accordingly. By the end of the day, the water in the tank has been circulated many times through the collector and has been heated to usable hot water temperatures.
If the circulating pump is regulated by an electronic differential controller, a sensor at the outlet of the collector and a sensor at the bottom of the tank (Figure 1) activate the circulating pump when the water in the collector is about 15-200 F warmer than the water at the bottom of the tank. The pump then circulates water from the collector and the tank. This process continues as long as the water temperature at the collector outlet is about 50 F higher than that in the bottom of the tank. If the temperature difference decreases further, the controller automatically shuts off the pump.
Common appliance timers also may control system operation. The timer is set to operate during a period of the day when solar radiation is available to heat the potable water. It is important that the timers used in these systems incorporate battery back-up in the event of power failures. In order to avoid loss of energy from the tank during overcast days, the collector feed and return lines are both connected at the bottom of the storage tank. During normal operation, natural stratification allows the warmer water to rise to the top part of the tank.
During periods of insufficient sunshine or high hot water demand, a backup electrical element in the storage tank heats the water. The check valve prevents heat loss when the circulating pump is off. The circulating pump consumes only a small amount of electricity ?around $5 to $10 worth per year, or in the case of PV ?none.
Figure 1. A solar water heating system<Table of Contents>
Q: What size solar system do I need?
For Florida residences with a dishwasher and an automatic clothes washer, a rough rule of thumb is 10-square-feet of collector area, per person, and 20 gallons of water storage, per person. Thus, for a family of four, 40-square-feet of collector and a total tank storage of 80 gallons are typical. It must be noted that ICS and thermosiphon systems will include two tanks, the solar system tank as well as the auxiliary tank.
Families can also purchase a solar-assisted system that uses a 20-to 26-square-foot collector that is retrofitted to their existing 40-or 52-gallon water heater. Due to the reduced storage tank capacity and smaller collector size, these systems will only provide 50-60% of the hot water used. The installed price will of course be lower since the existing tank and smaller collector are used.
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Q: How much do I save?
Your monthly savings will depend on the amount of hot water you use, storage tank size and type and price of fuel used for backup water heating. For a family of four, the typical hot water usage is 70- gallons per day, thus using 3990-kilowatt-hours per year to heat the water electrically, or $399 per year worth of electricity at 10?per kilowatt hour.
A solar water heater should save between 50% and 85% of the hot water portion of the monthly utility bill, or $200 to $300 per year for a family of four, if the backup element is kept at 1220 F.
A solar water heater can save even more if you turn off the backup and rely solely on the sun for your hot water. During summer months, when hot water demands are lower and the sun shines longer, most solar owners turn off the backup element circuit breaker, or switch. As electricity and other fuel prices go up, solar savings will increase accordingly.
An FSEC fact sheet, Solar Hot Water Energy and Cost Savings for Typical Florida Residential Installation, provides an overview of the potential savings from various solar systems available in Florida.
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Q: Do I have to change my habits to use a solar water heater?
No. Solar water heaters are always installed with a backup heating system in the storage tank to ensure that hot water is available at all times. However, to maximize solar utilization and your savings, you should attempt to use the most hot water in the late morning and early afternoon when the solar system is operating at its peak due to the available sunshine. Also, your solar system will be more effective if your use of hot water is spread more evenly over the week. For example, if you use hot water for laundry, instead of washing seven loads of clothes in a single day, wash one load each day. This will reduce the amount of backup energy required for your solar system.
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Q: How much does a solar water heater cost?
In Florida, an installed solar water heating sys-tem can cost anywhere from $3,500 to $6,500. Why the large range? System cost depends upon certain variables, such as the following:
Solar water heating is economically competitive with electrical and propane heating. It is also competitive with dedicated heat pumps and heat recovery units, depending upon the individual situation.
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Q: Does government offer any financial incentives?
There are currently federal tax credits available. In 2006, the Florida Legislature passed a state sales tax exemption for solar systems. Please call us at 407.574.6996 for further information.
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Q: How do I finance a solar water heating system?
The best way to finance a solar energy system is to include it as part of your home mortgage. In long-term loans of 20 years or more, the monthly solar savings will normally be greater than the monthly mortgage payments for the solar system.
If you are buying an existing home with a new mortgage, you may be able to include a new solar water heater in the mortgage. Check with your local lending office. Also, many Florida lending institutions offer short-term loans for solar systems, based upon the applicant's personal credit rating. Some solar companies also offer system financing.
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Q: What kind of a solar collector should I buy?
There are basically two types of solar collectors available for solar water heating. The first is referred to as a flat-plate glazed solar collector. The second is the integral collector storage (ICS) collector (Figure 2). Both collectors are mounted in a fixed position throughout the year and do not track the sun as do some collectors that are used primarily for high-temperature applications.
A basic flat-plate collector consists of a metal enclosure, an absorber plate and flow tubes, insulation, and a glass covering. Flat-plate collectors can be 2 to 4 feet wide, 5 to 12 feet long, and 4 inches thick. The absorber takes in the sun's energy, which is then transferred to the water flowing through the tubes attached to the absorber.
An ICS collector consists of large tubes, often 4 inches in diameter, in which potable water is both heated and stored in a combined heat storage and collection unit. As with the flat-plate collector, the ICS unit also consists of a metal enclosure, insulation, and a glass covering. ICS units are available in sizes ranging from 30 to 50 gallons, and can range from 4 feet in width to 8 feet in length to 10 inches in depth.
Figure 2. ICS collector
To reduce heat losses, all flat-plate and ICS collectors generally have insulation behind the absorber plate and a glass cover on the front, facing the sun. The best cover material is tempered glass of low iron content. Some edge insulation inside the enclosure box is also necessary.
The absorber plate is made of copper and is coated with a black chrome or nickel material called a selective surface. This surface greatly enhances the collector's ability to capture and retain solar energy. Some manufacturers also use black paint as an absorber coating.
The Florida Solar Energy Center conducts a state-mandated program of collector testing and certification. All collectors now sold in Florida should bear the Center's certification label.
A document entitled Thermal Performance Ratings, available from the FSEC Public Information office, contains the performance rating for each solar collector certified by the Center. The document also provides an approximate efficiency-per-dollar comparison method you can use as a guide for rejecting inefficient or overly expensive collectors.
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Q: Since there are several different types of solar water heating systems, how can I compare their performance?
FSEC conducts a state-mandated standards program for solar domestic hot water and solar swimming pool heating systems. The same solar collector can perform differently when installed in different system types. In addition, the other components (tank, pump, controller, etc.) selected for a particular system can have a large effect on the overall performance of a solar system. To allow comparison of complete systems, the "Florida Energy Factor" was devised to rate the performance of all solar system types. This factor is similar to the rating given to electric and gas water heaters.
The higher the energy factor, the more a solar water heater will save. The FSEC Public Information Office can supply energy factors for Florida solar systems, as can your solar vendor.
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Q: What is the proper orientation of the solar collector?
Collectors should be mounted on an unshaded area of a south-facing roof. They can face up to 45 degrees east or west of south without a significant decrease in performance.
For all shingle and tile roofs in Florida that generally have pitches greater than 3 in 12 (i.e., 14 degrees), collectors should be mounted parallel to the roof. Collectors mounted in this manner are more aesthetically pleasing. However, for flat or very low-sloping roofs, collectors should be tilted at an angle (to the horizontal) that is approximately equal in degrees to the local latitude. Florida latitudes range between 25 degrees (in the Florida Keys) to 31 degrees (northern border). Since the sun is lower on the horizon during the winter months, tilting the collector at an angle up to 15 degrees greater than latitude will increase winter performance, which is desirable in most cases.
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Q: How do I decide which solar water heating dealer to contact?
Compare price, efficiency, service options, dealer reputation and warranties. Ask the solar dealer for a list of previous customers, and talk to them. Ask the owners about performance. Does the system provide sufficient hot water? Was it affected by last winter's freeze? Inquire whether service has been necessary and if it was satisfactory. Ask about the warranty offered and read it carefully. A reputable dealer/installer will normally repair or replace a system component that malfunctions in the first year if the problem is caused by faulty materials, workmanship or installation.
The quality of installation can radically affect the reliable operation of a solar system. Installers should be licensed to install solar water heating systems. Installers should have either a state Solar Contractor or a Residential Solar Water Heating Specialty license or possess a separate license such as plumbing or air conditioning, which authorizes them to install solar residential hot water systems. Some local governments also have established a special solar contractor license.
In addition, many solar installers in the state belong to the Florida Solar Industries Association and abide by its Code of Ethics. As with other trades, your local Better Business Bureau can reveal any service or installation complaints against a vendor.
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Q: How do I protect my solar system from freezing weather?
Freeze protection is an absolute must for any solar system because a single freeze can destroy a collector. Even in Orlando, collector tubes have frozen and burst during hard winter freezes.
In order to avoid problems, Florida Solar Energy Center standards require that all solar systems be designed and installed with two freeze protection methods. The strategies and any instructions for the homeowner should be posted on a label affixed to a prominent location on the solar system, (usually the storage tank). There are a number of options available to prevent freeze damage to solar systems.
In the south and central Florida areas, flush-type freeze prevention valves are being used. These valves open when the air temperature approaches freezing. Water pressure forces water from the storage tank through the collectors and out through the valve. The valve closes when the water leaving the valve reaches 500 F. This process prevents the water in the collector tubes from freezing and rupturing the tubes. Though water is purged from the system and lost, only a few gallons are needed to protect the collector from freezing.
Another method of freeze protection is achieved by water recirculation. When the temperature drops below 400 F, a collector freeze sensor activates the pump to circulate warm water through the collectors. A second level of protection in this system, in the event of power failures, is provided by drain valves that manually drain the collector. Manual protection alone may be adequate for conscientious homeowners in southern Florida areas where hard freezes are rare. It is best to review the manual draindown instructions provided on the freeze information label or call your installer prior to manually draining your system.
ICS systems incorporate thermal mass freeze protection. The large size of the tanks in the ICS units requires a much longer and more severe period of freeze temperatures before all the water in the tubes freezes. Florida freezes are generally not severe enough to turn all the water in ICS tanks into ice. Nevertheless, piping on the roof and in attics must also be protected. ICS systems in central and north Florida also incorporate a freeze prevention valve as a secondary freeze protection mechanism.
In north Florida, an indirect system is often used (Figure 3). An antifreeze solution, similar to that used in automobiles, is circulated through the collector. A heat exchanger between the collector and storage tank transfers heat from the antifreeze to the potable water. Although this system is usually more expensive and less efficient than direct systems (in which the water used for bathing, etc., is the same water circulated through the collectors), it provides better automatic freeze protection in colder climates.
In some cases, thermosiphon systems also incorporate a heat exchanger in their design, which makes the thermosiphon design quite suitable for colder climates.
Two other types of freeze protection methods 梐utomatic drain-down and drain-back systems ?are used extensively in the northern United States and are also suitable for north and central Florida. Drain-down systems normally use electrically operated valves that automatically drain the water from the collector during freezing temperatures. In drain-back systems, the collector is automatically drained whenever the circulating pump stops. With careful design and installation, both drain-down and drain-back systems can be fail-safe and cost effective.
Figure 3. Indirect pumped system using antifreeze solution<Table of Contents>
Q: Are solar water heating systems reliable?
Properly designed and installed systems with glass-covered collectors should perform well for more than 20 years. Controllers, like other electronic devices, may require servicing during the life of the system, and the pump and hot water tank may have to be replaced after 10 years. Since conventional water heaters have the same expected lifetime, water tank replacement costs are not regarded as unique to solar energy systems.
Normal maintenance consists of checking pipe insulation, roof penetrations and collector mounting, pump operation and tank flushing. The latter is also recommended for conventional water heating systems, as is periodic replacement of the water heater sacrificial anode rod.
Many installation firms provide yearly maintenance check-ups of their solar systems similar to annual air-conditioning system maintenance programs. These can be beneficial in extending the life of the system and ensuring optimum performance.
It is important to request that the installer put an indicator on your solar system showing that the system is working. It can be as simple as a small light that comes on when the system is operating.
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Q: What other ways are there to save on water heating bills?
Besides simply using less hot water, and timing solar-heated water use to peak when the solar exposure is at its peak, the following strategies are suggested:
Finally, in a one-tank solar system, it's a good idea to have the back-up element controlled by a timer or manual on/off switch to keep it from coming on during the day. This strategy allows the solar system to produce all the hot water without the back-up heater being activated.
Timers may become very attractive if peak-load pricing of electricity is introduced. In that event, electricity would be priced at a much lower rate during certain hours of the day than at other times. Peak-load pricing is being evaluated by many electric power companies.
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Q:Is Solar Hot Water a good investment for me ?
The potential savings on water heating bills are affected the most by the type of fuel you are using to heat that water and the number of people in the home. If you are heating hot water for two or more people and you heat water with electricity or with bottled or natural gas, then you owe it to yourself to look at solar water heating, it could be a great investment for you.
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Q:What is the "payback" on a solar hot water system?
The term "payback" is a misconception that shows a false value towards an income generating device. Electric and gas water heaters do not have a payback! When you purchase a more efficient refrigerator, the decision to buy comes not from how long the savings generated will pay you back for your initial investment, but it comes from getting better service for a lower operating cost with a better rate of return. Solar water heating systems do just that. They provide quality hot water at a lower cost than heating with electricity or LP gas with more equity value in your home.
Solar collectors are typically designed to last as long as your home with little or no maintenance. These systems often give a 14% to 20% per year non-taxable rate of return on your money - even for a two person household. It is important to remember that hot water is a constant daily expense; other large household appliances, like air conditioners and heaters, are seasonal expenses.
Hot water is typically 20% to 30% of the annual utility bill. Hot water for showers, dishwashing, and laundry costs about $110 a year per person (when LP gas costs $1.15/gallon or electricity costs 7 cents/kilowatt hour). When electricity is 10 cents/kWh or LP gas is $1.60 a gallon, it will cost about $646 a year to heat water for a four person household. A properly sized solar water heating system can be expected to save this household $450 to $600. And Kingeagle Solar has several passive and active solar hot water systems to accommodate households from two to ten people, all of which qualify as a non-taxable investment.
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Q:What about this investment in a solar hot water system?
It is ironic that you, if you are an individual using LP gas or electricity to heat water, will pay for a solar hot water system over the next 4 to 8 years whether you get one or not!! You can invest today in a solar hot water heating system and have monthly savings and increased equity value in your home, or you can pay the local utility company every month. Your solar system savings will offset your payments, so you will actually own your solar water heating system at the end of five years. Remember that all solar savings are in non-taxable income, so a dollar saved on your water heating expense is equivalent to $1.30 or more of your taxable income.
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Q:What is the guranttee for the distributor?
With confidence of our quality and our quality control, we give our guarantee for 5 years of our products sold to oversea and relative guarantee for the accessories with limited liability:
1. Guaranteed subject
Main solar water heater products has 5 years guarantee for followings:
• storage tanks
• solar tubes
• frame
• reflect panel
• other parts approved by us
• All accessories has its own relative guarantee, it is not including this guarantee
2.limited liability
We are responsible for the above parts of our solar water heater for 5 years and if there are any problem, users can call our nearest distributors for exchange or repair or refund. But our responsibility are not applying for following conditions:
• bad weather: like heavy hail (dia. Of hail over 25mm), storm. For such weather, it is out of our control and user should cover like other treasure insurance.
• Improper installation and wrong operation of user: solar water heater are an professional products and should be installed by our distributor or these technical people approved by us. If by improper installation, user can not get proper result of solar water heater can caused damage.
• Bad water quality + improper maintenance: If the water quality too bad, there will be too much water dirt accumulating inside the solar tube and will affect the performance of the same. Therefore, we require the user to give proper maintenance according to our advice.
• For refund, it will be calculated on the value of the products purchased and by the invoice. It will be divided into 5, if the problem arise in third of the year, the user can get 2/5 of the purchased value, if it arise from second year, user can get 3/5 purchased value. If during the first of year, it will be 4/5. And the last year, 1/5.
• The third party damage
Transportation damage: after our shop deliver the product to users, the risk also transferred if there are any need of transportation.
ore information....
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Q:What about freezes and cloudy weather?
Both active and passive solar water heating systems come with a 100% lifetime guarantee against freeze damage. The active and the passive solar water heating systems are both approved by the Florida Solar Energy Center for use in North Florida. Active solar systems have a conventional electric heating element to heat water on the few days that it might be needed. Passive solar systems act as a pre-heater to heat water before it is drawn into the cold inlet of the standard gas or electric water heater. All solar water heating systems deliver both higher temperature water and more water volume than conventional water heaters. Typically 40 to 80 gallons more hot water than conventional water heaters.
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Q:What about heat recovery units instead of a Solar Hot Water Heater?
Testing by Florida Utility Companies and the State Energy Center reveal that heat recovery only saves about $39 to $69 a year - only 1/10 of the savings of solar energy systems. First, a heat recovery unit does not save any money when you are not heating or cooling. It saves the most money when you are air conditioning, because during this time the heat pump or air conditioner has free heat to expel. However, in the winter when a heat pump must pump heat into the house from the outdoors, there will only be minimal water heating savings. In addition, heat recovery units can have problems with freezing during the winter and scaling on the heat transfer equipment - this reduces the efficiency of the unit. A heat recovery unit also might require a whole house water softener to correct the scaling problem. A water softener isn't needed for a solar system. And, a solar system, unlike heat recovery, can be connected to all household water heaters.
Solar is the best way to qualify an Energy Star Home for a low interest mortgage. Note: Solar energy is exempt from sales tax in the state of Florida.
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Q:What about the appearance of a Solar Collector on our roof?
Today solar collectors are typically integrated into the slope of the roof. This method of installation gives the solar collector the appearance of a quality, opaque, glass skylight. In most cases, since the piping is not seen, it actually improves the appearance of the home because it looks like an elegant, expensive skylight.KINGEAGLE offers a free solar site survey to determine the location of the solar collector, and to verify that you will not have any collector shading problems. You typically need only about 4 hours of direct sun (between 9am to 4pm) per day.
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Q:What about the environmental benefits of going solar?
Any time you use solar energy to offset the amount of fossil fuels that are burned, you contribute to everyone's health and welfare. Operating one solar water heater instead of an electric water heater saves the equivalent of nine barrels of oil every year and reduces carbon dioxide emissions (a greenhouse gas) by 1600 pounds and sulfur dioxide (contributes to acid rain) emissions by 12 pounds. Multiply those emissions per household by all the homes in your neighborhood, town, county, or state, and the benefits -- and the air and water -- become even more clear. Environmental Consciousness is a state that induces action through your belief in leaving a better world for yourself and future generations. We are all free to believe what we choose and what we each do, attests to what we believe.
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Q:Let the Sun make your monthly payments!!
All banks and lending institutions will loan you money to put in a solar system. The good news is that even for two people the equity value and savings will result in a net positive income for the length of the loan and that equity value has been proven to last over 30 to 40 years. Then the system will generate $300-$600 in non-taxable income each year. Solar hot water systems usually cost $2,400 to $3,600 depending on the size and type of system you install. KINGEAGLE has a payment plan called "Let the sun make the payments," where we finance 1/2 the total cost of the system over 3 to 5 years at 6% interest. The money you save on your monthly utilities is actually being used to purchase your own water heating system.
Solar Energy...the Choice is Yours!
The only choice is what you are going to be getting for your money - you will be incurring a monthly debt with no equity and higher payments with no savings or return, if you do not go solar.
The choice is not about spending money. The choice is only about what you actually "get" in return for a continuing monthly debt. You are spending money anyway - either you invest it for more home equity and savings, or you give it away for a service provided by your local utility.
For example, if you could either lease or buy a car, making equal payments for five years, which would you do? Pay to lease or pay to own!? Then you can start keeping utility profits for your own nest egg.
EVERY DAY THE SUN RISES. . . and every day you could be saving money and enjoying the revitalizing power of sun heated water...
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ELECTRIC/ GASWATER HEATING
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vs |
SOLAR HOTWATER HEATING |
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1. Pay 100% of your water heating bill.
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vs |
1. Eliminate 80 to 95% of your water heating bill. |
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2. Constantly rising yearly utility bills
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vs |
2. Constantly increasing savings in non-taxable income.
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3. No equity or increased value in your home
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vs |
3. Your home equity value increases because of your investment.
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4. Monthly payments for hot water with no return on your investment
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vs |
4. Income generator produces a monthly positive cash flow.
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5. Creates air pollution and puts heavy toxic metals into our air and water.
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vs |
5. Uses non-polluting free solar energy.
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6. Often runs out of hot water.
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6. Doubles the amount of hot water available.
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BOTTOM LINE!
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Money Spent |
vs |
Money Earnedwith
built-up equity in your home and a non-taxable rate of return on your solar system of 15% to 20% per year. 423% return the first year on an Energy Star Home.
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