Once you have decided what size solar panel system you want, the next stage is to judge what type of solar panels will meet your needs. This should not be decided based solely on price, because power efficiency, longevity, warranty, and space needed are also important factors.
All too often people base their purchasing decisions on price alone, and then in two years wonder why no-one picks up the phone from the “fly-by-night company” they purchased their solar panels from when the inverter dies or their output is cut in half. It’s also quite important to recognise 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 it’s important to know the advantages and disadvantages of them all. If your only hurdle for purchasing panels is cost, then I suggest you compare “like with like”. It’s senseless to compare the price of Mono with the latest Amorphous panel and make your purchasing decision according to the price alone.
One of the most important distinctions to make with regards to solar panels is the differing 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 have a performance warranty that may last up to 25 years, and a guarantee of five to ten years. Also, your specialist can provide a warranty on workmanship, which is typically five years. Ask your solar retailer who will be providing the warranty, the name of the importer and/or manufacturer, and what steps are likely to happen if something goes wrong.
You should be aware that if a cheap solar panel importer stops trading in the future, their warranty obligation ceases. You’d probably feel far more comfortable with a well-known brand that has service agents for warranty work in Australia.
These are three main types of solar panel available, each with their own benefits:
Monocrystalline Cells
Monocrystalline panels are a proven and reliable technology, used over the past 50 years and still popular today. They have the best conversion efficiency at 12-18% of all sunlight. As these have the highest power to size ratio, they are the best option if you have 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 cared for.
Disadvantages:
Monocrystalline cells don’t perform as well as other panels in shady conditions, and they are quite fragile. They tend to be more expensive to manufacture due to their complexity.
Polycrystalline Cells
Polycrystalline compares fairly well in performance and longevity to monocrystalline, and provides an efficiency of 12-13%. Well known brands include BP SX, Sharp and Kyocera.
Polycrystalline panels have great longevity (around 25 years). They work optimally at 25 degrees C but 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 lower efficiency at 6%, however, Cadmium Telluride Thin-Film panels (CdTe) have progressed to 11% efficiency. These are more suitable for inland Australia conditions where space is no problem and temperatures are hot. Amorphous panels do not lose energy in higher heats.
Disadvantages are: Lifespan is reduced; 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 goal of recouping your set-up 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 regularly get higher than 40 degrees celcius and there is some cloud cover (these panels also work much better in the shade}, then these panels could be for you.
The Requirements of Solar Panels
With all types of solar panels, the owner must ensure they are kept free from dirt and shade, because these factors have a bearing 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 actually fit into the space you want to place them? Each solar panel is about 1.6 m long by 0.8 m wide. A 1.5kW solar panel system requires around 12 m² 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 specialist can calculate it precisely when quoting. You may want to be conservative with the space, however, 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.