The Blessings of The Sun
Q: What is Solar Energy ?
A: Solar energy is radiant light and heat from the Sun harnessed using a range of ever-evolving technologies such as solar heating, photovoltaic's, solar architecture and artificial photosynthesis. Solar power is the conversion of sunlight into electricity, we can change sunlight directly to electricity using solar cells. Every day, light hits your roof's solar panels with photons (particles of sunlight). The solar panel converts those photons into electrons of direct current ("DC") electricity. The electrons flow out of the solar panel and into an inverter and other electrical safety devices. The inverter converts that "DC" power (commonly used power). AC power is the kind of electrical that your television, computer, and toasters use when plugged into the wall outlet.
Q: What happens on dark/cloudy days?
A: Unlike the early days of solar power when systems had to be sized for peak loads, a grid-connected PV system seamlessly switches to draw from the utility grid when needed. As such, Sunlight Electric uses an annual production target, averaging out sunnier days with cloudy days.
Q: What is photovoltaic's (solar electricity) or "PV"?
A: What do we mean by photovoltaic's? 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, photovoltaic's could literally be translated as light-electricity. And that's just what photovoltaic materials and devices do; they convert light energy to electricity, as Edmond Becquerel and others discovered in the 18th Century.
Q: How can we get electricity from the sun?
A: When certain semiconducting materials, such as certain kinds of silicon, are exposed to sunlight, they release small amounts of electricity. This process is known as the photoelectric effect. The photoelectric effect refers to the emission, or ejection, of electrons from the surface of a metal in response to light. It is the basic physical process in which a solar electric or photovoltaic (PV) cell converts sunlight to electricity. Sunlight is made up of photons, or particles of solar energy. Photons contain various amounts of energy, corresponding to the different wavelengths of the solar spectrum. When photons strike a PV cell, they may be reflected or absorbed, or they may pass right through. Only the absorbed photons generate electricity. When this happens, the energy of the photon is transferred to an electron in an atom of the PV cell (which is actually a semiconductor). With its new found energy, the electron escapes from its normal position in an atom of the semiconductor material and becomes part of the current in an electrical circuit. By leaving its position, the electron causes a hole to form. Special electrical properties of the PV cell—a built-in electric field — provide the voltage needed to drive the current through an external load (such as a light bulb).
Q: What are the components of a photovoltaic (PV) system?
A: A PV system is made up of different components. These include PV modules (groups of PV cells), which are commonly called PV panels; one or more batteries; a charge regulator or controller for a stand-alone system; an inverter for a utility-grid-connected system and when alternating current (AC) rather than direct current (DC) is required; wiring; and mounting hardware or a framework.
Q: How long do photovoltaic (PV) systems last?
A: A PV system that is designed, installed, and maintained well will operate for more than 20 years. The basic PV module (interconnected, enclosed panel of PV cells) has no moving parts and can last more than 30 years. 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.
Q: What's the difference between PV and other solar energy technologies?
A: There are four main types of solar energy technologies:
Q: How is a solar electric system designed, installed, and maintained?
A: You could install a photovoltaic (PV) or solar electric system yourself. But to avoid complications or injury, you will probably want to hire a reputable professional contractor with experience in installing solar systems. PV systems have few moving parts, so they require little maintenance. The components are designed to meet strict dependability and durability standards so they can stand up to the elements. However, they are fairly sophisticated electric systems, so installation usually requires the knowledge and experience of a licensed electrical equipment contractor.
Q: Where can I find someone who designs, installs, and maintains photovoltaic (PV) systems?
A: We suggest you look for a PV installer or equipment provider in the telephone directory under "Solar Energy Equipment and System Dealers." It is a good idea select a designer or installer of solar energy systems from the list in your local yellow pages by first asking for information from several of them about their experience with PV systems as well as how much their services and products cost. With a system designer, you can discuss power requirements or hot water needs for your building, sunlight availability, and other important factors, and determine the type of system that's needed to meet your needs. System designers and installers should be able to provide you with cost estimates and other pertinent information. If your house is not yet designed or built, it is important to make the building as energy efficient as possible to reduce your PV system's energy requirements.
Q: How much does a solar energy system cost, and how much will I save on utility bills?
A: Some of the following documents are available as Adobe Acrobat PDFs. Download Acrobat Reader. Unfortunately, there is no single or simple answer. But a solar rebate and other incentives can reduce the cost of a PV system. This cost depends on a number of factors, such as whether it is a stand-alone system or is integrated into the building design, the size of the system, and the particular system manufacturer, retailer, and installer. For solar water heaters and space heaters, you also have to consider the price of the fuel used to back up the system. In most cases, you would have to add the cost of natural gas or electricity to get a more accurate estimate of how much you can expect to pay for a solar energy system. It is also difficult to say how much you will save with a solar energy system,because savings depend on how much you pay your utility for electricity or natural gas, and how much your utility will pay you for any excess power that you generate with your solar system. You can ask your solar system provider how much your new system will produce
on an annual basis and compare that number to your annual electricity or hot water demand to get an idea of how much you will save.
Q: What is net metering? Is net metering available where I live and work?
A: Net metering is a policy that allows homeowners to receive the full retail value for the electricity that their solar energy system produces. The term net metering refers to the method of accounting for the photovoltaic (PV) system's electricity production. Net metering allows homeowners with PV systems to use any excess electricity they produce to offset their electric bill. As the home owner's PV system produces electricity, the kilowatts are first used for any electric appliances in the home. If the PV system produces more electricity than the homeowner needs, the extra kilowatts are fed into the utility grid.
Q: What rebates are available?
A: Rebates vary from year to year depending on the funding for particular programs and the size of the PV system. Sunlight Electric will give you the most current information and include that in your proposal.
Q: How do we apply for a rebate?
A: Relax, that's our job. We believe that the easier we can make the purchase of a clean photovoltaic system, the more people will buy them, the better off we'll all be. That's why we work to make the process as easy as possible, and handle all the rebate and utility company paperwork for you.
Q: Can the rebate request be rejected?
A: In most cases, rebate reservation requests are processed in 6-8 weeks. When funds are not available, projects are waitlisted. No evaluation of the recipients are made beyond making sure the components of the system are on the “approved” list.
Q: Is financing available?
A: The best source of financing is usually the bank or finance company that you currently work with. If you like, we're happy to make arrangements with a number of independent mortgage brokers we've worked with on other projects.
Q: Someone told me that the energy required to make PV panels is greater than they will every produce. True?
A: Glad you asked! We've heard this one before. Numerous studies indicate it takes 2-3 years to generate as much power as is required to manufacture photovoltaic's, and the Environmental Working Group's Green Energy Guide reports an energy return on investment for photovoltaic's of 9-to-1, greater than most other electricity sources (i.e., coal: < 8:1, wind: 5:1, nuclear: <5:1, biomass: 3:1)
Q: I hear manufacturing PV panels creates toxic by-products and waste. True?
A: Another good one, which we've also heard before. There's less documentation on this than the energy return on investment question, suggesting it's probably not an issue, but the Environmental Working Group's Green Energy Guide reports the manufacturing and operation of photovoltaic's creates far less emissions than any other source of electricity analyzed.