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Solar Thermal FAQs

What is a solar water heater and how does it work?

A solar water heater uses the sun’s energy to pre-heat household water before it enters the conventional gas (or electric) water heater. Solar water heaters supply hot water for domestic use such as cooking, drinking, bathing and laundry. Solar water heaters consist of a roof-mounted flat plate collector panel that contains fluid (glycol, a food grade antifreeze) that is heated by the sun. The heated fluid is pumped into a heat exchanger in the home where it transfers it’s heat to the domestic hot water system.

Will I run out of domestic hot water if the sun isn’t shining?

No. Although a collector panel will capture some solar energy every day, a supplemental heat source is used as a backup for cloudy days, short winter days or periods of high hot water usage. The backup water heater uses an additional energy source such as gas or electric to keep the water at the desired temperature.

Can I use my present water heater as a backup for a solar water heater?

Yes. A new solar water heat tank can work in combination with your present water heater. A higher efficiency, space saving alternative is to purchase a solar water heater that supplies supplemental hot water, using electric, gas or oil, in a single unit.

Do I have to change my habits to use a solar water heater?

No, but you can increase your savings by attempting to use the most hot water in the late morning and early afternoon when the solar system is operating at its peak. Solar water heaters are always installed in addition to your existing water heater. Also, it helps to spread your cleaning load over the week. For example, instead of washing seven laundry loads all at once it would pay to do one a day. This will reduce the amount your existing water heater must operate.

How does it work in cloudy weather or if there’s no sun for several days?

The sun must be “out” in order to gather maximum solar energy, however, the backup system always insures that you have plenty of hot water. Running out of hot water is not an issue for solar users. In fact, with the lower cost, you can feel free to use hot water lavishly.

Where are the panels installed?

In a shade-free location, usually on a sloped or flat roof, although a rack on the ground is an option. South-facing panels are ideal, but West-facing panels are also possible.

What is the proper orientation of the solar collector?

Collectors should be mounted on an un-shaded area of a south-facing roof. They can face up to 45 degrees west of south with some decrease in performance. Additional equipment can be added to respond to the needs of homes whose roof is closer to east and west. Mounting the panels on an outbuilding or a ground mounted system might be an option for these homes.

Since there are several different types of solar water heating systems, how can I compare their performance?

A solar contractor, such as Bristol Electronics, will provide the necessary engineering, documentation, and analysis to aid in your selection.

Can I use a solar hot water system for space heating?

Solar water heaters can also be used to provide space heating. The same set of solar collectors can be used to provide hot water for both domestic hot water and space heating needs, although space heating will generally require a much greater collector area and storage capacity. Additional controls and heat exchangers are also needed. Due to these extra costs, and because sunshine is relatively scarce when heating loads are highest (for example at night and during the winter) solar energy is more often used to heat domestic water than it is for space heating.

Can I use the sun to heat the water in my pool?

Solar heaters are often the most economical way to heat a swimming pool. Compared to conventional pool heaters using propane or oil, solar pool heating systems can pay for themselves in 1-4 years or less. If you currently don’t heat your pool, a solar heating system can provide an economical way to extend your pool season, starting earlier in the spring and extending later into the fall. Solar pool heaters work by circulating pool water directly through collectors and then rerouting the warmed water to the pool. System controllers sense when collectors are warmer than the pool water, and open valves diverting water from the pool circulator through the collectors and then back into the pool. The controller can be set to automatically keep the pool temperature anywhere between 65 and 100 degree Fahrenheit. The collectors used for pool heating
systems are often less expensive than those used for domestic hot water systems, providing significant economic advantages.

Can I supply hot water for my business?

Commercial facilities with hot water demands and access to a good southern exposure can be great candidates for solar hot water. Restaurants, bakeries, beauty salons, health clubs, and hotels are all potentially good sites. A commercial installation generally makes use of the same system design and components as residential systems, including a conventional back-up for hot water heating during high load and low sun periods. Bristol Electronics can help you determine the applicability of solar for your site.

How much does a solar water heater cost?

An installed solar water heating system can range from $8,000 to $11,000 depending on hot water usage, mount type (roof mounted or ground mounted), number of solar flat-plate collectors. Financial incentives such as rebates and tax credits will significantly reduce this price. Savings will increase as a greater percentage of your domestic water is heated by free solar energy.

Is a solar water heater a good investment for me?

A solar water heater is designed to supply over 2/3 of the domestic hot water needs for a family. The monthly savings from installing a solar water heater depends on your domestic hot water needs and your current water heating fuel. Customers who currently use an electric water heater will see the greatest savings with solar. Let Bristol Electronics help you determine your potential savings.

Are solar water heating systems reliable?

Properly designed and installed systems should perform well for more than 20 years with minimal servicing. The solar collector panels unique to a solar hot water system have no moving parts and should last for 20 years or more. Maintenance and replacement schedules for water storage tank and conventional backup heating system are no different when used with a solar hot water system.

Are there any financial incentives in addition to the fuel savings?

Federal tax credits and state incentives have been created to encourage the use of solar technologies. Some apply only to residential installations and some are intended for commercial and government use. Funding, incentives and expiration dates change frequently. Currently, there is a federal tax credit available to help lower the final cost for residential systems. It is 30% of the installed cost and is scheduled to expire in 2016. The State of Vermont also offers a rebate to residential and commercial property owners who install solar water heaters. Bristol Electronics can help you figure out which tax credits and incentives you qualify for.

How long does it take for a solar heater to pay for itself?

Solar heating does have a payback, and it can vary from four to ten years. But it may be more useful to think of solar as an investment that yields an annual return, much as a bank savings account provides interest. A solar water heater will generate savings that can equal a bank account generating a twenty percent (20%) annual return, and the savings are not taxed as income, as is the interest you earn at the bank. The truth is, if you want hot water…you will be paying for that heat. You may prefer to pay the utility bill forever, or you may wish instead to go solar, and become your own utility. It is quite similar to the reason you once decided to buy your home and stop renting. Solar is simply the best investment available today because it guarantees a return on money that you will otherwise “burn” and helps you develop equity as you bank your

Will my property taxes go up if I install a solar energy system?

In Vermont real estate taxes are generally not charged on solar systems at this time. Please check with your local town clerks office to confirm this within your town.

Will a solar energy system add equity to my home?

We are finding financial institutions are lending money based on the added equity and real estate appraisers are recognizing the added value for resale