Once you have decided what size solar panel system you would like, the next stage is to judge what kind of solar panels will meet your needs. This shouldn’t be decided based solely on price, as power efficiency, longevity, warranty, and the area needed are also important factors.
All too often people base purchasing decisions on price alone, and then in two years wonder why no-one answers the phone from the “fly-by-night company” they purchased their solar panels from when the inverter dies or the output is cut in half. It’s also quite important to know that there are different qualities of panels on the market and you should compare “apples with apples”.
There are three main types of panels: Monocrystalline, Polycrystalline, and thin-film or Amorphous, and you should learn to recognize the advantages and disadvantages of all of them. If your main hurdle for buying panels is price, then I suggest you compare “like with like”. It’s silly to compare the price of Mono with the latest Amorphous panel and make your purchasing decision from the cost alone.
One very important distinction to make regarding solar panels is the range wattages available. Watts are related to the output of each panel, so a 200W panel would output 200 watts per hour. You can expect to pay twice the price of a 100W panel.
Warranties
Solar PV (photo-voltaic) panels come with a performance warranty that should last up to 25 years, and a guarantee of five to ten years. In addition, your specialist can provide a warranty on workmanship, which is typically five years. Ask your solar retailer who is providing the warranty, the name of the importer and/or manufacturer, and what steps are likely to happen if something breaks.
You should be aware that if a cheap solar panel importer stops trading sometime in the future, their warranty obligation ceases. You’d probably feel far more at ease with a well-known brand which has service agents for warranty work in Australia.
The following describes the three main types of solar panels available, each with their own benefits:
Monocrystalline Cells
Monocrystalline panels are a proven and reliable technology, used for the past 50 years and still popular today. They have the best conversion efficiency at 12-18% of all sunlight. Because these have the highest power to size ratio, they’re the best option if you’ve got limited roof space. They also degrade very slowly, generally losing 0.25 – 0.5% per year. Their lifespan can be 25 years, and even up to 50 years if taken care of.
Disadvantages:
Monocrystalline cells don’t perform as well as other panels in shady conditions, and they are quite fragile. They can be more expensive to manufacture due to their complexity.
Polycrystalline Cells
Polycrystalline compares fairly well in performance and longevity to monocrystalline, and provide efficiency of 12-13%. Well known brands include BP SX, Sharp and Kyocera.
Polycrystalline panels have great longevity (around 25 years). They work best at 25 degrees C and will lose some efficiency at higher temperatures (over 50 degrees C), which is common in the Australian summer.
Amorphous Thin Film
Thin film panels typically have a much lower efficiency at 6%, however, Cadmium Telluride Thin-Film panels (CdTe) have progressed to 11% efficiency. These are more suitable for inland Australian conditions where space is no problem and temperatures are hot. Amorphous panels do not lose energy in higher heats.
Disadvantages are: Lifespan is less; there is a 3-6 month breaking-in period; and they typically require double to triple the roof space for the same output of crystalline cells.
When choosing your solar panels remember to focus on the aim of recouping your initial costs through savings in electricity. The more efficient and higher watt panels will do this faster. However, if you are looking at solar farms in Outback Australia where temperatures routinely get above 40 degrees celcius and there is some cloud cover (these panels also work much better in the shade}, then these panels may be suitable.
The Requirements of Solar Panels
With the various types of solar panels, the owner must ensure they are kept free from dirt and shade, because these factors impinge on solar power output.
Panels are installed facing north and at a roof angle of a minimum 10 degrees. Do the solar panels you want physically fit in the space you want to install them? Each solar panel is about 1.6 m long by 0.8 m wide. A 1.5kW solar panel system requires around 12 m of north-facing roof space. As mentioned, this footprint varies depending on the type of panel. Don’t worry if you can’t work out the amount of unshaded space the roof has for your panels, because your installer will calculate it precisely when quoting. You may want to be conservative with the space, though, in case you wish to add more panels later to cover more of your energy needs.
My Solar Price specialise in solar power, solar hot water, and solar pool heating quotes. For three free quotes you can visit My Solar Price.