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  • Frequently Asked Questions

    Frequently Asked Questions

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    General Questions

    What is solar energy?

    Solar energy takes advantage of the sun's rays to generate heat or electricity. It is an infinitely renewable resource and unique for its ability to generate energy in a quiet, clean, and consistent manner.

    What's the difference between solar photovoltaic and solar hot water systems?

    While both types of solar systems capture energy from the sun, solar photovoltaic systems use photovoltaic panels to produce electricity. Solar hot water, or thermal, systems capture sunlight to heat water for domestic use, to heat a swimming pool, or for a radiant heating system.

    What factors are important to consider when installing a home solar energy system?


    The location of your home and the local climate will play into where you place and how you install your solar electric or solar hot water system. Wind speeds, heavy snow loads, and salt water, for example, can all affect a solar array. Understanding how those inputs affect performance will determine the types of mounts or how the arrays are angled. A solar pro in your area is quite knowledgeable about your local conditions and can help you design a system that works well for you.

    Can I finance a home solar energy system?


    Yes! Consider using a home equity loan for the purchase and installation costs of a solar photovoltaic or solar hot water system to take full advantage of federal tax deductions, credits, and/or rebates. Solar energy systems are viewed as a major home energy savings upgrade and there are financial tools out there that reward you for your efforts. Remember, installing a solar energy system is comparable to any other upgrade you might do to your home, such as installing a new deck or remodeling a kitchen. Financial advisors have current information on available federal, state, and local tax incentives.

    Also, many people now lease solar PV systems, which makes the systems much more affordable than direct purchase.  Discuss lease possibilities with your contractor or solar company.

    Will I need a building permit to install a solar energy system in my home?


    Yes. You'll need to obtain building permits to install a solar photovoltaic or solar hot water system. Similarly, building, electrical, and plumbing codes also apply. That said, residential solar power systems do not use "radical" building techniques and most jurisdictions have building codes that fully embrace solar energy technology. Solar professionals will roll the price for permits into their cost estimate and will often take care of the entire permitting process for you.

    Why is it important to get multiple bids?


    As with any major purchase, it's helpful to compare costs and information. Seeking information from multiple professionals can provide constructive advice, set realistic expectations, and help you fine-tune the design that will work best for your application.

    How can I calculate the cost and payback time from a solar power installation?


    You can estimate how much a solar electric or solar hot water system may cost if you determine your current energy needs and costs and compare those costs against your future anticipated use. Once you have a sense of how much energy you use, you can evaluate the cost of purchasing and installing one or both of the technologies.

    Luckily in today's market you can take advantage of multiple federal, state, and local tax credits, rebates and other financial incentives that create attractive and competitive prices for solar PV and hot water systems.

    How long will it take to install a solar power system in my home?


    Planning, configuring, and any custom ordering for your solar energy system can take up to a few weeks. However, the installation process itself can typically be completed in only a few days time, in many cases even less.

    How do energy efficiency and conservation measures relate to my purchase or lease of a new solar energy system?


    Energy efficiency and conservation are an important part of maximizing the benefits of a new solar energy system.  A thorough contractor/company will perform a home energy audit before installing a solar energy system, especially a photovoltaic system.  Conserving energy and using high-efficiency products will help accelerate your solar energy systems return on investment and will save the greatest amount of money possible in utility costs.

    Which parts of the United States have the greatest potential for harnessing solar energy?


    The American Southwest is prolific in the amount of sunshine it receives and, thus, its solar potential.  Arizona, southeastern California, and much of New Mexico are ideal locations residential, commercial, and utility-scale solar energy systems.

    Photovoltaic Questions

    What is photovoltaics (solar electricity) or "PV"?


    What do we mean by photovoltaics? The word itself helps to explain how photovoltaic (PV) or solar electric technologies work. First used in about 1890, the word has two parts: photo, a stem derived from the Greek phos, which means light, and volt, a measurement unit named for Alessandro Volta (1745-1827), a pioneer in the study of electricity. So, photovoltaics could literally be translated as light-electricity. And that's just what photovoltaic materials and devices do; they convert light energy to electricity.

    How do solar photovoltaic cells work?


    Photovoltaic cells are comprised of a semiconductor material such as silicon. Added to the silicon are the elements phosphorous and boron, which create conductivity within the cell and activate the movement of electrons. The electrons move across the cell when activated by the sunlight's energy into the electrical circuit hooked up to the solar panel.

    What is the difference between solar panels and building integrated photovoltaic products?


    Solar panels are flat panels of photovoltaic arrays mounted on a roof, a pole, or the ground to capture the sun's rays. Building integrated photovoltaic materials (BIPV) are PV arrays that are integrated into the building material itself, primarily windows, roof tiles, or walls. Solar panels work well for retrofits or remodels while BIPV are appropriate for new construction or a major renovation.

    How reliable is solar power?


    Solar systems built today are very reliable. They have proven to be dependable sources of energy for large office buildings, mass retailers and governmental agencies, supplying megawatts of energy to people and business across the country. Some of the largest companies in the world have buildings powered by solar energy, including eBay, WalMart, and the US Air Force.

    Will solar work on my home or business?


    The two biggest factors are the amount sunlight the building receives during the day and the amount of open roof space. Most solar contractors and companies can give a quick assessment by looking at satellite photos of a property. PV systems today can be blended easily into both traditional and nontraditional buildings. The most common practice is to mount modules onto a south-facing roof for homes.  Beyond traditional roof mounting, businesses utilize PV for security lighting, parking lot covers, bus shelters, and more.

    Will I need to adapt my home or business to run on solar power?


    No. Solar power electric systems fit seamlessly into buildings. You won't have to buy new appliances or change your electrical outlets; everything will work just the same as it did before. You should experience no practical changes except for one: smaller electric bills every month!

    What size solar system do I need?


    Every home and business is different, so the size of your system will depend on your energy needs, roof space and solar goals. Residential solar power systems are typically 3-10 kW and commercial solar power systems range from 50–500 kW for a medium sized business.  An energy audit and analysis is the first step in determining what size solar system your home or business needs.

    What is a grid-tied solar electric system and what is an off -grid solar electric system?


    Grid-tied solar electric systems are connected to a utility’s electric grid. When a home or business needs more electricity than the PV system provides, it supplements that with the utility’s electricity. When the home or business generates more electricity than it uses, that electricity goes directly into the grid.

    Off-grid solar electric systems are not connected to a utility’s electric grid. Any building that is off-grid relies completely on electricity generated by its own PV system. Off-grid systems usually have batteries to store electricity for use when its PV system is not generating electricity. Grid-tied PV systems are much more common than off-grid systems and represent the vast majority of solar electric system installations.

    What components make up a solar electric system?


    The components of a solar electric system are a photovoltaic array to capture the sun’s energy, an inverter to convert the direct current (DC) produced from the photovoltaic cells into alternating current (AC) used by the home or business, and a utility meter – called a net meter – that can record both the electricity produced from the power system as well as any power used from the grid.  These three system components are then connected through wiring.  The photovoltaic panels are secured to the roof with panel mounts or are installed on poles that can be adjusted for sun angle.  In some circumstances, it makes sense to mount the panels on the ground.

    How much maintenance do solar energy panels require?


    Solar photovoltaic panels require little maintenance – no need to wash or dust. It is, however, important to place panels where they will remain clear of shade and debris. They need to be cleaned occasionally if they collect excess dust or leaves.

    Solar hot water collection arrays don't need much attention either. It does help to periodically use a window wash brush, biodegradable soap, and water to clean the tubes.

    How long will a solar system last?


    Most of the parts on a solar system, such as solar panels, carry manufacturers’ warranties of 25 years; other parts, such as inverters, carry 10-year warranties. Many solar systems far outlast their warranties; a great deal of the first solar systems installed more than 30 years ago are still going strong. The best way to ensure and extend the life and effectiveness of your PV system is by having it installed and maintained properly. Experience has shown that most problems occur because of poor or sloppy system installation.

    Do I need a battery back-up system?


    No. Battery systems are expensive and are generally not recommended. Almost all solar electric systems are connected to the utility grid so you always have access to a power source. You never have to worry about "running out" of power.

    What happens at night or when the weather turns cloudy?


    Since the amount of power your solar system generates is a direct result of sunlight, it will produce slightly less energy when the weather is cloudy. Your system will not produce any energy at night. Because the solar power system will be interconnected with your local utility grid, you can automatically begin to draw power from the grid whenever you need it. You won’t experience any power interruptions—the switch between solar system power and the utility grid happens seamlessly, with no effort on your part.

    What happens if there is a black out?


    In the event of a black out, your system is designed to turn off. This is a safety requirement by the utility company so that their technicians can safely repair down electrical lines.

    How much space do I need for a PV system?


    In bright sunlight, one square foot of a conventional photovoltaic panel will yield 10 watts of power. That's a helpful rule of thumb for calculating a rough estimate of how much area you might need. For example, a 1,000 watt system (1kW) may need 100 – 200 square feet of area, depending on the type of PV module used.

    How many solar panels do I need for a PV system?


    The size of the photovoltaic system is correlated to your home or business’ energy-use needs, available space for a system, and overall costs for the system components and installation. Solar contractors in your area can help determine the best size for your solar photovoltaic system.

    How much shading is too much for solar photovoltaic panels?


    Unfortunately shading a photovoltaic system dramatically decreases its output. Just shading the bottom row of wafers alone amounts to an 80% reduction in efficiency. Trees that provide any shade to a proposed PV site will need to be pruned back to ensure that the area receives full sunlight.

    What is net metering? Is net metering available where I live and work?


    Net metering is a policy that allows homeowners to receive value for the electricity that their solar energy system produces. The term net metering refers to the method of accounting for the PV system's electricity production. Net metering allows homeowners with PV systems to sell back to the utility any excess electricity they produce to offset their electric bill.

    Solar Thermal Questions

    What are solar hot water systems?


    Solar hot water systems, broadly termed solar thermal systems, use the sun's energy to heat water. Solar hot water systems can be used to heat a hot water tank or to warm a home's radiant heating system. Swimming pools and hot tubs use a modified solar hot water system for heating water.

    How does a solar water-heating system work?


    Every solar water-heating system features a solar collector that faces the sun to absorb the sun's heat energy. This collector can either heat water directly or heat a "working fluid" that's then used to heat the water. In active solar water-heating systems, a pumping mechanism moves heated water through a building. In passive solar water-heating systems, water moves by natural convection. In almost all cases, solar water-heating systems work in tandem with conventional gas or electric water-heating systems; the conventional systems operate as needed to ensure a reliable supply of heated water.

    There are many types of solar water heaters. Each has strengths to recommend it for specific climates and water conditions. Solar system professionals can help you select the most appropriate system for your area and your needs.

    Can a solar water heater replace an electric or gas water heater?


    Not completely. Conventional electric or gas water heating systems are still necessary as a supplement to the solar water heating system, largely because the sun might not shine in a particular area for several days at a time. However, because solar water heaters are designed to provide hot water directly to the tank of a gas or electric water heater, they reduce the need for the water heater to run on conventional fuels. This, in turn, reduces your gas or electric bill. Depending on where you live, solar water heaters can provide up to 80% of your home's annual water-heating needs.

    Can I use a solar water-heating system to heat my swimming pool?


    Using a solar system to heat a swimming pool is the most common use for solar energy in the United States today. Solar pool-heating systems increase an unheated pool's water temperature by 10 degrees or more, and they can extend the swimming season by two to three months.

    What are the benefits of using solar energy to heat water in my home?


    The fuel is free! Once you recover the higher initial costs of a solar system through reduced or avoided energy costs (that is, lower utility bills), your solar system will require expenditures only for maintenance. And when you include the cost of a solar water heater in a mortgage on a new home, the system often provides a positive monthly cash flow from the first day of ownership.

    Can I use solar power to heat my home?


    Absolutely! Radiant heating applies solar thermal technology. Transferring solar energy through pipes into an under floor radiant heating system is a wonderful way to stay warm. Radiant floor systems are typically 40 percent more efficient than their forced air counterpart and can be zoned to match thermal comfort to each room.


    These FAQs were compiled with information from the following websites:
     
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