Heat Your Water with the Sun

8/14/2019 Heat Your Water with the Sun

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A Consumers Guide

Heat YourWater with the Sun

Bringing you a prosperous future where energy is clean, abundant, reliable, and affordable


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Background

What is solar heating? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2What are the basic components of a solar thermal system? . . . . . 2

How have solar systems improved? . . . . . . . . . . . . . . . . . . . . . . . . 5

Investing in solar thermal technologies

Why should I invest in a solar thermal system? . . . . . . . . . . . . . . 6

How much will your solar heating system help theenvironment? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Is my home a good place for a solar heating system? . . . . . . . . . . 6How big should my solar thermal system be, and whichfeatures should I look for? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

How much money will my solar thermal system save, andhow much will it cost? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

How can I finance the cost of my solar thermal system?Are there incentives? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

What are the maintenance issues and repair costs for a solarthermal system? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Selecting a solar heating contractor

Who sells and installs solar thermal systems? . . . . . . . . . . . . . . 13

How do I choose among solar thermal system providers? . . . . . 13

How do I choose among bids? Is the least expensive thebest deal? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Before you put solar heating to work

Do I need a conventional system as a backup? . . . . . . . . . . . . . . 15Will I need any permits or inspections? . . . . . . . . . . . . . . . . . . . . 16

What about insurance? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Will I need warranties? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Will I need a maintenance agreement? . . . . . . . . . . . . . . . . . . . . 16

Getting help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Contents

Cover photo: The people living in this house enjoy hot water that is

heated with a solar thermal system. (Courtesy of Industrial Solar Technology/PIX12964)

Photo opposite: Flat-plate solar collectors heat this pool in Oregon.

The unglazed polymer collectors sit on top of a flat roof and provide

shade to the patio below.


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Would you like to learn more about how the sun can help meet yourhomes heating needs without straining your budget?

Todays solar heating systems not only keep swimming pools warmthey can also heat much of your homes water and interior space. Their

popularity is increasing, for several reasons. Solar heating systems arereliable, adaptable, and pollution-free because they use renewable energyfrom the sun. Many systems include sleek, attractive, low-relief collectorsthat people often mistake for skylights.

Did you know that solar heating systems work well in many differentclimates? Some applications, such as pool heating, are widely cost-effective today. The cost-effectiveness of other applications depends onspecific circumstances, such as the type and cost of your usual source ofenergy. Today, special financing is available to help you purchase thesystem thats right for your home.

If youd like to find out more about solar heating for your home or pool,this booklet is a good place to start. Here, youll learn how solar heatingsystems work, how theyre used, their benefits, and how to purchase oneyourself. Please note, however, that this booklet isnt a technical guideto designing and installing a system. For that, youll need to consult an

experienced solar heating contractor; see Getting help in this bookletfor more information.

A solar heating system is a substantial but rewarding investment. It canreduce your monthly heating bill while helping to protect our environ-ment. Being informed and planning carefully will ensure that youvechosen the right system for you and your family.

Heat Your Water with the Sun

Gen-Con,

Inc./

PIX09320


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What is solar heating?

Solar heaters, or solar thermal

systems, provide environmentallyfriendly heat for household water,space heating, and swimming pools.The systems collect the suns energyto heat air or a fluid. The air orfluid then transfers solar heatdirectly or indirectly to your home,water, or pool.

Solar water heaters, sometimescalled solar domestic hot-watersystems, may be a good investmentfor you and your family. Solar waterheaters are cost effective for manyapplications over the life of thesystem. Although solar waterheaters cost more initially than

conventional water heaters, the fuelthey usesunshineis free. Solarheating technologies can be usedin any climate. To take advantageof solar energy, you usually need to

have an unshaded area that facessouth, southeast, or southwest,

such as a roof. In some cases, a solarprofessional may recommend west-facing roofs for solar collectors.

The type of system you choose,including the type of collectorand whether it is active or passive,depends on several factors. Theseinclude your site, the climate you

live in, installation considerations,cost, and how you would like yoursolar heating system to be used.

What are the basiccomponents of a solarthermal system?

Solar water heaters and solar spaceheaters are made up of solar collec-tors, and all systems except poolheaters have some kind of storage.In pool systems, the swimming poolitself is the storage, and the poolsfiltration pump circulates the poolwater through the collectors.

Active systems also have circulatingpumps and controls; passive sys-tems work without this addedequipment.

Three types of solar collectors areused for residential applications:flat-plate, integral collector-storage(ICS), and evacuated-tube collectors.

Flat-plate collectors like the oneshown on page 3 are the mostcommon type. Glazed flat-platecollectors essentially are insulated,weatherproofed boxes that containa dark absorber plate under oneor more glass or plastic (polymer)

Background

Simplified representation

of a solar water-heating system

Roof-top collector

Solar-heatedtap water

Solar storage tank/

conventional backup heater

Swimming pools and your homemay also be heated using solar energy


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covers. Unglazed flat-plate collec-tors are simply a dark absorberplate, made of metal or polymer,without a cover or enclosure.Unglazed flat-plate collectors madefrom polymer materials are typicallyused in solar pool-heating systems.

See the photos on pages 1 and 7and the diagram on page 9 forexamples.

Integral collector-storage systems,also known as ICS or batch sys-tems, are made of one or moreblack tanks or tubes in an insulated,glazed box. Cold water first passes

through the solar collector, whichpreheats the water, and then con-tinues to the conventional backupwater heater. ICS systems are sim-ple, reliable solar water heaters.However, they should be installedonly in mild-freeze climates becausethe outdoor pipes could freeze in

severely cold weather.

Evacuated-tube solar collectorsare usually made of parallel rows oftransparent glass tubes. Each tubecontains a glass outer tube andmetal absorber tube attached toa fin. The fin is covered with a

coating that absorbs solar energywell, but which inhibits radiativeheat loss. Air is removed, or evacuat-ed, from the space between the glasstubes and the metal tubes to form avacuum, which eliminates conduc-tive and convective heat loss. In the

United States, evacuated-tube col-lector systems are used most fre-quently in commercial applications.

Most solar water heaters requirea well-insulated storage tank.Solar storage tanks have an addi-tional outlet and inlet connectedto and from the collector. Active

solar systems usually include astorage tank along with a conven-tional water heater. In two-tanksystems, the solar water heaterpreheats water before it enters theconventional water heater. In a one-tank system, like the one shownon page 4, the backup heater is

combined with the solar storagein one tank.

Active solar water heaters usepumps to circulate water or a non-freezing heat-transfer fluid fromstorage tanks through the collec-tors. Active systems are usually

Glazed flat-plate collector

Inlet connection

Glazingframe

Enclosure

Flow tubesGlazing

Outletconnection

InsulationAbsorber plate


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more expensive than passivesystems, but they are also usuallymore efficient.

Direct circulation systems use apump to circulate household waterthrough the collectors and into thehome; they work well in climateswhere it rarely freezes. Indirect

circulation systems use pumpsto circulate a non-freezing heat-transfer fluid through the collectorsand a heat exchanger. This heatswater that then flows into thehome. Indirect systems are popularin climates prone to freezingtemperatures.

Passive direct solar waterheaters, like the one shown onpage 5, move household water ora heat-transfer fluid through thesystem without using pumps orelectricity. Passive systems workduring power outages, but they

should not be used in climateswhere temperatures often go belowfreezing. Passive systems are typical-ly less expensive to purchase andmaintain than other types of solarsystems. They are also inherentlymore reliable and may last longer.However, passive systems are notusually as efficient as active systems.

ICS passive solar systems maybe best in areas where temperaturesrarely go below freezing. They arealso good in households withsignificant daytime and eveninghot-water needs.

Thermosyphon systems work

because water flows through thesystem when warm water rises ascooler water sinks. In this system,the collector must be installedbelow the storage tank so thatwarm water will rise into the tank.These systems are reliable, but

Active indirect one-tank system

Collector

sensor

Collector

Controller

PumpAir

eliminator

Expansion tankPressuregauge

Fill/drainassembly

Air vent

Drain

Drain

Element

Cold water in

Hot water out

P/T reliefvalve

Heatexchanger

Tank

FSEC


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contractors must pay careful atten-tion to roof design because thewater in the storage tank is heavy.Thermosyphon passive solar sys-tems are usually less expensive thanactive systems, but more expensive

than ICS systems.

How have solar systemsimproved?

Since the early 1970s, the efficiencyand reliability of solar heating sys-tems and collectors have increased

greatly and costs have dropped.Improvements to materials, a ratingsystem for consumers, and moreattractive designs have all helpedto make systems more successful.

Low-iron, temperedglass is now usedinstead of convention-

al glass for glazing.Improved insulationand durable selectivecoatings for absorbershave improved effi-ciency and helped toreduce life-cycle costs.

The Solar Ratingand CertificationCorporation (SRCC)and the Florida SolarEnergy Center (FSEC)certify and rate solarthermal systems andequipment. SRCCevaluates product

reliability and ratesthe performance ofsolar water-heatingsystems by subjectingthem to technicalreviews. SRCC has a

directory of certified systems onits Web site along with systemperformance ratings. FSEC publishessimilar information specific toFlorida that is useful in other stateswith similar climates. See the

Getting help section for contactinformation.

The appearance of the systems hasalso improved. Todays collectorscan usually be mounted flush withthe roof for a streamlined systemthat looks like skylights. Unglazed

polymer collectors for solar poolheating are now available in terracotta colors as well as black, sohomeowners can choose the colorthat will best match their home.

5

Passive direct system

Freezeprevention

valve

Fromcollector

To collector

ICS Collector

Drain valve

Check valve

Isolation valve

Pressure/temperaturerelief valve

Pressurerelief valve

Shutoffvalve

Dip tube

Top element

Water heater tank

Hot water out

Cold water inThree-wayball valve

Bottom element

Drain

Drain valve

FSEC


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Why should I invest in asolar thermal system?

The first question many people askwhen considering a home expenseis, How much will it cost? Theanswer depends on the type of sys-tem, how you want to use it (wateror pool heating, for example), andyour geographic location. But mostsolar thermal systems cost between

$2,000 and $4,500. Although thisis usually more than the cost of aconventional gas or electric system,todays solar heating systems arecost competitive when you consideryour total energy costs over theentire life of the system.

Your monthly gas or electricity billswill usually be lower and morepredictable for as long as you ownthe house. Also, solar heating sys-tems will insulate you from risingfossil fuel costs and protect youfrom fuel-price inflation over time.Investing in a solar thermal systemcould also increase the resale value

of your home. Often, the entireinitial cost of the system can berecovered when you sell yourproperty. In addition, you willbe earning an annual 6% to 25%tax-free rate-of-return on yourinvestment, depending on howmuch hot water you use and how

much energy you save.

Another important reason to investin solar systems may be less tangi-ble. When you purchase a solarheating system, you support tech-nologies that are good for theenvironment. You are making a

conscious, responsible decision tohelp reduce harmful emissions from

fossil fuels, while maintaining yourquality of life.

How much will your solarheating system help theenvironment?

Depending on the type of conven-tional fuel used, replacing an elec-

tric water heater with a solar heatercan offset the equivalent of 40% to100% of the carbon dioxide emis-sions of a modern passenger car.

Carbon dioxide traps heat in ouratmosphere, contributing to thegreenhouse effect, which altersour planets climate and ecologicalsystems. Using solar energy in placeof nonrenewable fuels may alsoreduce nitrous oxides and sulfurdioxides, which are componentsof smog.

Is my home a good place fora solar heating system?

The first consideration when build-ing a solar thermal system is thesite. If your site has unshaded areasand generally faces south, it is agood candidate for a solar thermalsystem. A professional installer canevaluate your roof as a location for

collectors. If your roof doesnt haveenough space, you can also installthe system on the ground. Pleaserefer to the system-sizing section ofthis booklet for more informationon space requirements. The amountof sun that your site receives,how often temperatures dip below

Investing in Solar Thermal Technologies


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freezing, and other factors willalso affect the type of solar heatingsystem you choose.

Before getting under way, you needto consider your homeowners

association rules and neighbor-hood bylaws, also known as codes,covenants, and restrictions (CC&Rs).In Arizona, California, and Florida,state laws prohibit CC&Rs thatrestrict solar system installations.Nine other states have similar lawsbarring regulations that unreason-

ably limit solar energy use inplanned communities. Some citiesand counties have ordinances orrequire permits for home improve-ment construction, including solarsystem installation.

How big should my solarthermal system be, and whichfeatures should I look for?

Some of the answers to questionsabout system size and features

depend on how you plan to usethe solar system. Here, youll findgeneral information on sizingsystems for water heating, swim-ming pools, and space heating.To locate more specific information,please see Getting help onpage 17.

Sizing a solar thermal systemfor heating domestic water

Just as conventional water heaterscome in different sizes, so do solarwater heaters. Sizing your solar

Solar pool heaters are efficient and economicalHeliocol/PIX08874


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water heater involves determiningthe total collector area and storagevolume you need to meet 90% to100% of your household's hot waterneeds during the summer. Solar-equipment experts use worksheets

and computer programs to helpdetermine system requirementsand collector sizing.

Contractors usually follow aguideline of about 20 square feet(2 square meters) of collector areafor each of the first two family

members. For every additional per-son, add 8 square feet (0.7 squaremeters) if you live in the Sun Beltarea of the United States, or 12 to14 square feet (1.1 to 1.3 squaremeters) if you live in the northernUnited States.

For active systems, the size of the

solar storage tank increases withthe size of the collectortypically1.5 gallons per square foot of collec-tor. A small, 66-gallon system isusually big enough for one to threepeople; a medium-size, 80-gallonsystem works well for a three- orfour-person household; and a large,

120-gallon system is appropriatefor four to six people.

In recent years, homebuilders havebegun including solar water heatingsystems as standard features insome subdivisions. The systems arethe same size for every home, andthey all work equally well. However,

large families with greater hot-waterdemand find that a smaller percent-age of their hot water is provided bythe solar energy system.

Sizing a solar thermal systemfor heating swimming pools

Heating your swimming pool withsolar energy requires a collectorthat is 50% to 100% of the surface

area of your pool. Your geographiclocation and other factors deter-mine the exact size.

For example, a 15-by-30 footswimming pool in Florida typicallyrequires a collector that equals100% of the pools square footage,which translates to 450 square feet

of unglazed flat-plate collectors.This is because many Florida swim-ming pool owners use their poolsyear round. In contrast, in northernCalifornia, most pools are used only6 to 8 months per year, so systemsare typically sized at 60% to 70%of the pools surface area.

In general, adding more squarefootage lengthens the swimmingseason and allows owners to use thepool in colder weather. A pool coveror blanket reduces heat loss andhelps maintain warm temperaturesfor a longer period.

Sizing a solar thermal systemfor space heating

In contrast to solar water heating,solar space heating usually requiresa larger, more complicated system.Space-heating systems have to storeheat for use when solar energy isleast available and your house is

coldestat night and during thewinter months. Solar space-heatingsystems are usually combined withwater heating, and they are sizedto accommodate both uses.


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The amount of solar collector areaneeded to heat your home dependson many factors. These include the

available solar energy, collector effi-ciency, local climate, and heatingrequirements. Heating requirementsare based on insulation levels, thehouses airtightness, and the life-style of the residents. Generally, thearea of solar collector is about equalto 10% to 30% of the floor area of

the house.

How much money will mysolar thermal system save,and how much will it cost?

Your savings depend on how yoursolar system will be used, as well as

the size and type of your system.Other factors can include theclimate, the contractor, and the

system rating. Your state may offersolar rebates or other incentivesthat will reduce costs.

Savings and costs for solardomestic water heating

Solar heating systems can saveyou money in the long run. FSEC

studied the potential savings toFlorida homeowners who usecommon water-heating systems,including solar, in comparisonto electric water heaters. FSECundertook this study because theinitial installed cost of a solar water

Solar pool-heating system

Collector

Sensor

Pump

Filter

Automaticcontrol box

D

B

EA

Gatevalve

Warm waterreturns to pool

Pool water in

C

F

Vacuum breaker/auto-air reliefA Check valve

B Gate valve

C Chlorinator(if applicable)

D Drain valveE Bypass valve

F Booster pump(if necessary)

Fossil fuel heater(if applicable)

FSEC


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heater is higher than that of a gasor electric water heater. FSEC want-ed to explore costs and savings overtime, beyond the initial installationperiod. The study found that solarwater heaters offered the greatest

potential savings. Annual utilitycosts for solar water heaters were50% to 85% lower than those forelectric water heaters.

The cost and benefit of purchasinga solar water heater vary fromregion to region, so check costs in

your area. Depending on the priceof the conventional fuel, a solarwater heater can be more economi-cal over the life of the system thanheating water with electricity, fueloil, propane, or even natural gas.Thats because the fuelsunshineis free.

However, at historically low pricesfor natural gas, the total cost ofowning a solar water heater witha backup natural gas heater maybe more expensive than owninga natural gas heater alone.Nevertheless, as natural gasbecomes more costly and its avail-

ability more volatile, solar waterheaters become more economical.Solar water heaters are often quitecost-competitive in new homes.

In many places in the UnitedStates, homebuilders chooseelectric water heaters because theyare easy to install and relatively

inexpensive. Research shows thatthe average household with anelectric water heater spends about

25% of its home energy costs onheating water.

If you are building a new homeor refinancing because of a majorrenovation, the economics are even

more attractive. Including the priceof a solar water heater in a new30-year mortgage usually amountsto between $13 and $20 per month.The federal income tax deductionfor mortgage interest attributableto the solar system reduces thatby about $3 to $5 per month. So,

if your fuel savings are more than$15 per month, the solar invest-ment is profitable immediately.On a monthly basis, you are savingmore than you are paying.

Savings and cost for solarswimming pool heating

A solar heating system for yourpool usually costs between $3,000and $4,000 to buy and install. Thisprovides a payback of between1.5 and 7 years, depending on thecost of the fossil fuel your systemreplaces. The actual cost and pay-back depends on your site, the typeof system you choose, financing,

and the length of the pool season.

Often, a payback cannot even becalculated, because many peoplechoose not to heat their pool at all,given the extra $300 to $600 ontheir energy bill. A solar systemallows these people to swim in a

pool that was previously too costlyto heat and too cold to use.


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Savings and cost for solarspace heating

The cost of a solar space-heatingsystem depends on many factors,including the size of your house,

how airtight it is, how much ofyour heat will be supplied with aconventional backup, the systemyou choose, and your site. Ingeneral, solar space-heating systemscan provide 40% to 60% of yourspace-heating needs. These systemsare most economical for consumerswho would otherwise be heatingwith electricity, rather than withnatural gas or other fuels.

But solar space heating is neededmost when sunlight is leastavailable, during the winter andat nightand needed least whensunlight is most available, during

the summer and the daytime. Sotodays solar technologies are notlikely to be a cost-effective solutionfor active solar space heating inmost homes. However, a good alter-native is to simply to use passivesolar building techniques. See theEERE Web site, www.eere.gov/solar,for more information.

How can I finance the costof my solar thermal system?Are there incentives?

Financing

Financing the cost of your solarthermal system is not as trickyas it may seem. Although somespecial programs are available tohelp you purchase solar thermaltechnologies, most of the financingoptions are familiar ones.

One common way to finance a solarsystem is through your mortgage orthrough a home-equity loan securedby your home. Mortgage loansoffer lower interest rates and longerpay schedules than conventional

bank loans, and interest on yourmortgage loan is tax-deductible.Financing your system when youapply for your mortgagewhetherbecause you are building or refi-nancingcan make the applicationprocess simpler and less costly.

Conventional bank loans areanother way to finance your solarsystem. However, your system is along-term investment; this shouldbe reflected in the pay schedule forthe loan. Look for longer terms andlower interest rates, which will helpkeep your solar thermal systemaffordable.

Incentives

Many states have incentives forbuying solar technologies. Checkwith your state or local energyoffice or your state departmentsof revenue or finance for informa-tion. Some electric utilities offer

rebates to customers who installsolar energy equipment becausethese installations help utilitiesreduce energy use during timesof high demand.

You can also check the NationalDatabase of State Incentives for

Renewable Energy (DSIRE). DSIREis prepared by the North CarolinaSolar Center. It provides informa-tion on financial and regulatoryincentives to promote renewableenergy technologies. For informa-tion, see Getting help on page 17.


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What are the maintenanceissues and repair costs fora solar thermal system?

The costs of maintaining your solarthermal system depend on the type

of technology you choose and howoften temperatures in your area fallbelow freezing. Properly maintainingyour system will keep it runningsmoothly.

Passive systems do not requiremuch maintenance. For activesystems, discuss the maintenancerequirements with your systemprovider and consult the systemowners manual. Plumbing andother conventional componentsrequire the same maintenance asconventional systems. Glazing

may need to be cleaned in dryclimates where rainwater doesnot provide a natural rinse.

Regular maintenance on simple

systems can be as infrequent as

every 3 to 5 years, preferably bya solar contractor. Systems with

electrical components usually

require a replacement part or two

after 10 years. Simple, regular sys-

tem checks can also be effective.

For example, one easy way to

check the system is to carefully

feel the hot-water pipes goinginto the storage tank after the

system has been working on a

clear, warm day. If the pipes are

hot, your system is working

properly.

Specialists can safely and efficiently install solar thermal systemsIndustrialSolarTechnology/PI

X12963


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Selecting a solar heating contractor

Who sells and installssolar thermal systems?

Depending on your area, thesimplest way to find a solarthermal systems contractor is tolook in the yellow pages underSolar Energy Equipment andSystemsDealers. Most of thelistings will probably be for solarwater heating, photovoltaic (solar

electric), or electric systemscontractors.

You can also contact your utilitycompany to get information onrecommended vendors, or searchon the Internet for solar waterheating, solar pool heating, or

solar space heating, depending onthe application you are interestedin installing.

Your state may have an activechapter of the Solar EnergyIndustries Association (SEIA), atrade association of contractors,distributors, and manufacturers.

See Getting help for contactinformation.

How do I choose amongsolar thermal systemproviders?

One way to choose a contractoris to check your list of potentialcompanies for the ones nearestyou. Ask them what products andservices they offer. Here are a fewquestions you might want to askpotential vendors.

Has your company installedsolar thermal systems for solar

water heating, pool heating,or space heating?

Choose a company that hasexperience installing the type ofsystem you want and servicingthe applications you select.

How many years of experience

does your company have withsolar heating installation?

Obviously, the more experiencethe better. A business that hasbeen working with these systemsfor a long time will be moreprofessional, know more aboutcurrent technologies and recent

advances, and be less likely tomake costly mistakes. Request alist of past customers who canprovide references.

Is your company licensed?

Having a valid plumbers or solarcontractors license is required in

some states for solar thermalsystem installation. You canconfirm licensing by contactingyour state contractor licensingboard. Local requirements mayalso include a local contractorslicense. Call your city and countyfor information on other requiredlicenses.

For you to obtain certain rebates,your contractor may have todemonstrate special knowledge


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about solar installations throughone or more of the following:

Possession of a solar contractorspecialty license issued by alocal building jurisdiction

Certification in solar thermalsystems by a group such as thestate chapter of SEIA

A letter from the solar heatingmanufacturer that indicatesthat the installer has the neces-sary experience and training to

install solar systems.

Does your company have anypending or active judgmentsor liens against it?

As with any project that requiresa contractor, due diligence isrecommended. Your state contractor

licensing board can tell you aboutany complaints against state-licensed contractors. The BetterBusiness Bureau is another goodsource for such information.

How do I choose among bids?Is the least expensive the

best deal?It is usually a good idea to get morethan one bid for installation of yoursolar system. Make sure that all thebids you receive are based on thesame information and require-ments. For example, comparing abid for a system mounted on your

roof with a bid for one mountedon the ground would not tell youhow the two bids compareitwould probably tell you more abouthow the two types of installationscompare.

One solution is to ask for bidson systems certified by theSolar Rating and CertificationCorporation (SRCC). If possible,have each bid specify system typeand size, energy output, mainte-nance requirements, and cost.Cost should include having thesystem installed and getting itup and running, as well as thecost of hardware, permits, salestax, and warranties.

A system warranty is crucial in

comparing bids. A solar rebateprogram may require a writteninstallation warranty, for examplea 2-year parts-and-labor warrantyin addition to manufacturerswarranties on system components.The company may offer other,longer warranties, particularlyon the collectors. However, solarsystems are more than collectors;active systems include electroniccomponents, pumps, valves, andwiring. Make sure you know whatyour warranty covers and thatthe company stands behind thefull warranty.

If you have several bids, you maywonder if the lowest bid is thebest deal. Sometimes it is not. Asolar thermal system installer isin business to make money; over-head and operating expenses mustbe covered. A low price could bea sign of inexperience, or of a

company without staying power.Contractors that expect to stay inbusiness must charge enough tocover their products and servicesplus make a fair profit. Price isnot the only consideration.


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Do I need a conventionalsystem as a backup?

Whether you need a backup systemfor your solar thermal systemdepends largely on the type ofsystem you choose and where youlive. Solar water-heating systemsalmost always require a backupsystem for cloudy days and timesof increased demand. This backup

system is typically a conventionalgas or electric water heater andmay already be part of the solarsystem package. It may also bepart of the solar collector, such asrooftop tanks with thermosyphonsystems. For example, an integralcollector-storage system (ICS)

may be packaged with an instanta-neous gas water heater for backup.

The ICS system stores hot water inaddition to collecting solar heat,

and the instantaneous water heaterprovides hot water when solar heatis not available.

Most people do not need or usea backup heater with solar poolheaters. In freeze-prone climates,solar pool heaters are used mainlyin summer. Spas or hot tubs are

an exception. Spa owners may usetheir solar system to heat both thepool and the spa, but will use abackup heater to get the spa to ahigher temperature. In climateswhere it rarely freezes, pool heatersmay be used year-round.

If you decide to install solar thermalspace heating, you will almost

Before you put solar heating to work

Rooftop collectors can be installed on most roofing materialsSunSystems/PIX05978


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certainly need a backup system.Space-heating systems require alarge collector area, significantstorage volume, and a highlyefficient building envelope toproduce enough energy to heat

your home at night and duringthe winter. Solar space heatingusually provides 40% to 60% ofyour homes space-heating needs.A backup system ensures thatyour house is comfortably warmduring power outages, cold snaps,and extended cloudy periods.

Many building codes and mortgagelenders require a conventionalbackup space heater.

Will I need any permitsor inspections?

If you live in a community witha homeowners association, checkto see if any approvals, permits,or inspections are required. Alwaysobtain the necessary approvalsfrom the association before begin-ning construction. Homeownersassociations, towns, cities, andcounties usually have a legal rightto require approval before building.

However, some states have solar-rights laws that may apply ifapproval is denied.

You will probably need to obtainpermits from the building depart-ment that has jurisdiction in yourstate, county, or city. Plumbing,building, and electrical permits maybe required. These permits typicallyrequire a final inspection after thesystem has been installed. Checkwith your solar heating systemcontractor to find out whether

the price of obtaining permits andinspections is included in the bidand final cost estimate.

What about insurance?

If you are buying a solar heatingsystem for your home, your regularhomeowners insurance shouldcover your needs. However, ifinsurance coverage becomes anissue, please refer to Getting helpon page 17.

Will I need warranties?Warranties are an important factorin the bidding process and animportant aspect of the systemyou choose. Make sure you knowthe warranties that your systemmanufacturer and installer offerfor your equipment and hardware,

as well as parts-and-labor war-ranties. Check to make sure themanufacturer can provide supportand supplies if the installer isnot available.

You can usually obtain a full-systemwarranty plus parts-and-labor forat least 1 to 3 years. This means

you will not be responsible forsystem problems covered by thewarranty in the first year or twoof system operation.

Will I need a maintenanceagreement?

A maintenance agreement maybe part of your warranty. Havethe contractor prepare a scheduleof required or recommendedmaintenance before you purchaseyour system.


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17

American Solar Energy Society (ASES)2400 Central Avenue, Suite G-1

Boulder, CO 80301www.ases.orgPhone: (303) 443-3130Fax: (303) 443-3212E-mail: [email protected]

Database of State Incentivesfor Renewable Energy (DSIRE)www.dsireusa.org

Florida Solar Energy Center (FSEC)Public Affairs Divisionwww.fsec.ucf.eduPhone: (321) 638-1015Fax: (321) 638-1010E-mail: [email protected]

National Renewable Energy Laboratory

Solar Energy Technology Programwww.eere.energy.gov/solar.html

Solar Benefits Model Softwarewww.eere.energy.gov/

solarbuildings/sbm.html

Solar Energy IndustriesAssociation (SEIA)1616 H Street NW, 8th FloorWashington, DC 20006-4999www.seia.orgPhone: (202) 628-7745Fax: (202) 628-7999

Solar Rating and CertificationCorporation (SRCC)c/o FSEC1679 Clearlake RoadCocoa, FL 32922-5703www.solar-rating.org(See standards document OG-300)Phone: (321) 638-1537Fax: (321) 638-1010E-mail: [email protected]

Getting Help

Solar thermal technologies work in a variety of climatesCraigChristensen,

NREL/PIX12943


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About the Office of Energy Efficiency and Renewable Energy

A Strong Energy Portfolio for a Strong America

Energy efficiency and clean, renewable energy will mean a stronger economy, acleaner environment, and greater energy independence for America. By investing intechnology breakthroughs today, our nation can look forward to a more resilient

economy and secure future.

Far-reaching technology changes will be essential to America's energy future.Working with a wide array of state, community, industry, and university partners,the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energyinvests in a portfolio of energy technologies that will:

Conserve energy in the residential, commercial, industrial, government, andtransportation sectors

Increase and diversify energy supply, with a focus on renewable domestic sources

Upgrade our national energy infrastructure Facilitate the emergence of hydrogen technologies as vital new "energy carriers."

The Opportunities

Biomass ProgramUsing domestic, plant-derived resources to meet our fuel,power, and chemical needsBuilding Technologies ProgramHomes, schools, and businesses that use lessenergy, cost less to operate, and, ultimately, generate as much power as they useDistributed Energy & Electric Reliability ProgramA more reliable energy

infrastructure and reduced need for new power plantsFederal Energy Management ProgramLeading by example, saving energyand taxpayer dollars in federal facilitiesFreedomCAR & Vehicle Technologies ProgramLess dependence on foreignoil, and eventual transition to an emissions-free, petroleum-free vehicleGeothermal Technologies ProgramTapping the Earth's energy to meetour heat and power needsHydrogen, Fuel Cells & Infrastructure Technologies ProgramPaving theway toward a hydrogen economy and net-zero carbon energy futureIndustrial Technologies ProgramBoosting the productivity and competitivenessof U.S. industry through improvements in energy and environmental performanceSolar Energy Technology ProgramUtilizing the sun's natural energy togenerate electricity and provide water and space heatingWeatherization & Intergovernmental ProgramAccelerating the use of today'sbest energy-efficient and renewable technologies in homes, communities, and businessesWind & Hydropower Technologies ProgramHarnessing America's abundantnatural resources for clean power generation

To learn more, visit www.eere.energy.gov

The National Renewable Energy Laboratory,

a DOE national laboratory, produced this Consumers Guide for:

U.S. Department of Energy

Office of Energy Efficiency and Renewable Energy

1000 Independence Avenue, S.W.

Washington, D.C. 20585

Documents

Heat Your Water with the Sun