Basic Pv (photovoltaic) Panel Components
June 12, 2010 by Go Green Tips · Leave a Comment
From the operators of www.GreenLivingRocks.com — providing education regarding how to make a solar panel, solar panel cost, and solar panels prices.
One of the reasons that building your own pv (photovoltaic panels has become so popular is that there are really very few parts involved. A regular solar panel consists of just a few basic parts, namely an enclosure, solar cells, a substrate and wiring. Here’s an outline of what’s involved.
Solar panel container or enclosure
This is what most people see when they think of a solar panel. It’s the clear glass top, the frame and the backing that the pv (photovoltaic cells are mounted on. The case can be hefty enough to need a custom built metal rack for mounting on a rooftop, or small enough to be a plastic box that can be placed almost invisibly near an outdoor floodlight. It needs to be resistant to ultra violet (UV) rays so that it does not deteriorate with constant exposure to sunlight. And the glass (usually Plexiglas) needs to be durable enough to withstand harsh weather, including hail and wind storms that could crash tree branches and other debris into it.
Substrate
This is the piece of wood, peg board or other material that the solar cells are mounted on inside of the enclosure. It also needs to be UV-resistant to survive prolonged exposure to direct sunlight.
Solar cells
The pv (photovoltaic cells are comparable to the silicon chips that power nearly all computers. They combine the silicon, metals and other materials in a way that captures direct sunlight and converts it into electricity. The electricity can either be immediately used by direct current devices (DC) like LED lights, or stored in DC batteries and changed into alternating current (AC) to power conventional appliances like refrigerators, TVs and other electrical equipment in homes and businesses.
Tabbed and untabbed solar cells
When constructing your own solar powered panels, you can save money by buying untabbed solar cells and soldering the tabs on top of the cells yourself. This can be a good choice if you have more time than money, but it’s a tedious job. You can save time by buying tabbed solar cells which will cut your soldering time by one-half to two-thirds.
Photovoltaic cell wiring
Once the solar cells are mounted on the substrate, they are wired to each other in a series so that they can generate electricity. Copper wire is added to connect the solar cells to storage batteries for using the electricity later, or to connect directly to the device that the photovoltaic panel is powering like an attic fan or a solar powered toy.
Blocking diode
The blocking diode is a tiny component that prevents electricity that is stored in a battery from draining backward into the solar panel. Bigger photovoltaic systems use a charge controller for the same effect.
What Kinds Of Hot Water Solar Collectors Can You Construct Yourself?
June 9, 2010 by Go Green Tips · Leave a Comment
From the operators of www.GreenLivingRocks.com — providing education regarding how to make a homemade solar panel, residential solar power, and solar roof tiles.
There are 3 main kinds of hot water solar collectors commonly used in homes: flat plate and evacuated tube systems. There are a number of various “recipes” for building each kind. But here is a brief description of their similarities and differences.
First, there are pool solar collectors. These are typically a type of flat plate design, but there are enough differences between solar pool heating systems and solar hot water heating systems that some clarification is necessary.
Pool solar collectors, are usually designed as rows of UV resistant black polypropylene pipe that is heat welded together. Because pool heaters require lower water temperatures than hot water for showers or for heating a house, the collectors do not need to be encased in a box. In fact, the polypropylene plastic is not proposed to withstand the high temperatures needed for other domestic hot water use, and should not be enclosed by glass.
Even though solar pool heating systems are about the simplest solar energy system that you can construct or install, the solar collectors themselves are not so easy to make. The polypropylene pipe does not respond to adhesives, and the procedure and equipment needed for heat welding is cost prohibitive for a do-it-yourself project. And using a substitute material may not be sensible because of its tendency to break down with ongoing exposure to the sun and chlorine from the pool. For this reason, it is probably easier to purchase the solar collectors even if you prefer to install the system yourself.
Evacuated tube solar collectors are also complex to build. Although they are used for domestic hot water and for heating a home with hot water, the materials require special handling. They use unique glass tubing with double walls. The air trapped between the walls act as insulation, comparable to the way dual pane windows trap air for insulation. The innermost tube can be filled either with water or with a heat transfer fluid to avoid freezing in freezing climates. Obviously, this kind of system is more complicated to build and install than a simple hot water heating system. Again, it might be easier to purchase the solar collectors unless you have a lot of ability and confidence.
Flat plate solar collectors, also used for residential hot water and heating, are usually easier for a do-it-yourselfer to build. The design is fairly simple and basic. Flexible tubing for the water is attached to an absorber plate and positioned inside of an insulated metal box. A glass cover is used, which allows the sun to heat the water. As the water is heated, it is pumped into an insulated storage container and held for use as required for bathing or washing dishes. With the aid of a decent set of instructions, constructing and installing a hot water system using flat plate solar collectors is a good project for people who are handy and motivated.
How Effective Are Solar Hot Water Systems?
June 7, 2010 by Go Green Tips · Leave a Comment
Solar hot water heating systems are fairly easy to install, simple to maintain and the most cost effective way to introduce your home to solar energy. They can save considerable energy and cost when they replace an electric hot water heater. And they can be successfully used even if you live in a climate where freezing temperatures are common during the winter.
If you live in a climate that does not have freezing temperatures, and your household consists of fewer than five people, you can install a batch heater. This is the least expensive solar water heating choice, and it is relatively easy to build if you have the inclination to do-it-yourself. It is simply a water storage tank that also serves as the solar collector.
The tank is enclosed in a glass-covered box that is situated to allow maximum exposure to the sun. The water in the tank heats up and hot water is available for use. However, it is not the most efficient system, since it takes longer to warm up an entire tank of water than to heat a flat panel solar collector. Plus as the tank cools at night, there is less hot water available for use.
There are two superior systems that can be used even in freezing regions. The direct pump system circulates water between a solar collector and a storage cistern. With this design, water in the solar collector can heat up faster, and the tank can be insulated for better temperature holding capacity. The pump can be designed to run on electricity from a photovoltaic cell if you desire to keep your system completely solar powered.
A thermosiphon system also uses a separate solar collector, along with the pull of gravity. And it allows for the use of an insulated storage reservoir for more consistent hot water delivery. When using either of these systems in cold climates where freezing is an issue, both the piping and the storage tank should be situated indoors and properly insulated to provide hot water even on the coldest days.
For more information regarding solar technology and how you can utilize solar power in your home or business, please visit http://www.GreenLivingRocks.com and http://build-a-solar-panel.info.
Look for our other posts. We are dedicated to providing information about solar power. Without using solar power as an alternative energy source, we are destined to completely wipe the world clean of natural resources. When we use renewable energy, we all win.
From one of our articles that can be found on our blog:
“A solar panel design has a specific set-up needed to make it work efficiently. The design has been refined over the years. Solar panels started out as very cumbersome pieces of technology. Today, these panels can be used in something as small as a calculator. When deciding on the placement of panels for home use. It’s helpful to know exactly what you need to get an entire solar energy system hooked up and running smoothly.”
From the operators of www.GreenLivingRocks.com — providing education regarding how to make a homemade solar panel, solar energy, and solar hot water.
