How much i can save if i build home made solar panels? — Bill Jones, Dallas, TX
Q: I live in the Northwest part of the U.S. where it is cloudy a lot of the time. Will solar work here?
A: Despite what many people think there is more than enough sunlight in the Northwest U.S. for most homeowners to make use of solar energy. The Northwest’s highest potential is in southeastern Oregon and southern Idaho; however, there are no “bad” solar sites. Even the rainiest parts of the Northwest receive almost half as much solar energy as the deserts of California and Arizona, and they receive more than Germany, which has made itself a solar energy leader.
Q: What happens when it snows. Will my solar panels still work?
A: Yes. Sunlight will penetrate a thin layer of snow and the snow will usually melt fairly quickly off of solar panels. If you have had a heavy snow you can help it along by using a squeegee on a pole to scrape off the surface layer of snow.
Q: If there is a power outage, will I still have power from my solar electric system?
A: That depends upon whether or not you are using a grid-tied system or an off-the-grid system using batteries. If you are using a grid-tied system you will lose power but could switch to a generator as a backup. If you are using an off-the-grid system or a hybrid system with batteries for storing your electricity then you won't lose power. This is the main advantage of an off-the-grid approach.
Q: How many solar electric panels would I need to completely power my house or apartment?
A: The obvious answer of course is it depends on how much energy you use. Another big factor is whether or not you are trying to supplement your energy supply with a grid-tied system or if you are off the grid and trying to cover all of your energy needs. Probably the easiest way to look at it is to consider a range based on the amount of roof space you have available for placing the solar panels. An installation with about 14 panels would probably provide about 40-%-50% of your energy needs. If you have a large roof area you can probably fit about 24, 125 watt solar panels and cover 75%-100% of your energy needs. If your roof is not south facing or if it is partially shaded the energy output will be somewhat lower. A reputable solar installer can help you determine what is practical for your home and the amount of power you can practically generate from the space you have.
Q: Does it make sense to install a solar system if we are moving in a couple of years?
A: Probably. Most real estate experts currently believe that given the concerns about energy costs a solar system will significantly raise a home's value. One source, the Appraisal Journal, states that the value of your home is increased by $20 for every $1 reduction in annual operating costs resulting from installed energy efficiency measures or energy generation systems. However, this very much depends upon the local market so you should probably confirm this with an experienced local real estate agent before making this decision if you know you are planning to sell in a relatively short period of time.
Q: What is the lifespan of the solar modules?
A: Most experts believe solar electric modules have a lifespan of at least 25 to 30 years and most manufacturers provide a warranty for this period. However, the truth is that we don't really know for sure since most modern solar panels have not been in existence that long. Many experts believe the actual number could be much higher, possibly as much as 50 years. What is very clear is that solar modules are extremely durable and lose very little of their energy generating capacity over time. This is one of the reasons that they make sense as a long-term investment.
Q: When it is cloudy or foggy, will my solar electric system still work?
A: Yes. The solar electric system will continue to operate under fog or cloud cover but its output will be reduced. The solar electric system’s power output is relative to the “depth” of the cloud cover and how much light gets in, but typical coastal fog only reduces power output by 50%. Winter storm clouds will cause substantially greater reduction but the system will still produce energy.
Q: Can you put solar on a flat roof?
A: Yes. Most commercial solar electric systems are installed on flat roofs. The solar panels are usually mounted on “tilt-racks” which put the panels at the optimum angle and face them in the right direction.
Q: Is the weight too much for my roof?
A: No, solar modules are very lightweight. The combined weight of the rails and solar modules is only 3 lbs per square foot.
Q: How much does a solar module weigh?
A: 23 pounds.
Q: How durable are the solar panels? What about hailstorms?
A: Solar modules are very durable, and constructed with strong aluminum frames and high strength tempered glass designed to withstand moderate hailstorms.
Q: How long does it take to install a solar electric system?
A: Solar electric systems usually take between two to five days to install, depending on the size and complexity of your solar electric system. However, in our experience the actual calendar time is usually longer because there are often delays waiting for the local energy company to install the electrical meter (in a grid-tied system) or waiting for local electrical inspectors.
Q: Are there any disadvantages to using solar energy?
A: Solar energy technologies often have a higher "first cost." This means that a person is likely to pay more money up front to purchase and install a solar system. Still, in nearly all cases, the high initial cost is recovered through substantial fuel savings over the life of the product. Another disadvantage is that solar energy approaches do require some direct access to sunlight. If you live an a very shaded area and do not have the ability to remove trees or other impediments to sun access it may not be an option for you.
Q: Do I need to install a new roof before the solar panels are installed?
Solar panels are very durable and most will last at least 25 years. Therefore, you definitely should consider the age of your roof before you install them. If your roof is more than 20 years old and in bad shape you will definitely want to consider replacing your roof before installing them. However, if your roof is in reasonably good shape go for it. In fact, adding the solar panels will actually reduce the wear and tear on your roof and make it last longer since the solar panels will block ultraviolet rays which can damage roof tiles and will help to keep snow and ice of your roof.
Do I need to clean the panels periodically?
A: In most areas of the country, there is sufficient rain to clean the panels. However, if you are in a dusty area (very near a busy dirt road, very urban area, etc.) you may see a performance gain from cleaning the panels monthly. If necessary, a hose stream is usually sufficient for cleaning. Do not walk on or over the panels to clean them. Do not use metal, hard, or abrasive methods for cleaning. Do not spray water on the panels when they are very hot.
Q: Why should I use photovoltaics (PV)?
Answer: For a growing number of users, PV is the clear choice. The number of installed PV systems increases each year because their many advantages make them the best option overall. Consider the following issues: