Types of electric solar panels
Solar panels are made up of varying numbers of solar cells, also called photovoltaic cells, which convert the sun’s energy into storable electricity by means of semiconductors, using the photovoltaic effect. These solar panels are generally called photovoltaic (PV) panels as opposed to thermal solar panels that produce hot water. Various different types of photovoltaic solar panels are available, the most common of which are rigid, and are known as crystalline silicon, either monocrystalline or multicrystalline. A more recent development is thin-film solar panels, which can be either rigid or flexible. They are typically more efficient, in other words they produce more electricity for the same amount of sunshine and area of solar panel, but at present they cost more than crystalline silicon panels in South Africa. Various sizes of solar panels are available, so when buying them it is best to work out the approximate amount of electricity required and choose the size accordingly.
Electricity storage (Batteries)
The electricity produced during the day, if not used immediately, is stored in rechargeable batteries for use when the panel is not producing electricity, such as at night or during heavily overcast weather. The batteries used depend on requirements; it is important to calculate maximum charge and discharge rates, as well as the quantity of electricity required, before selecting batteries. The batteries most commonly used are of the lead-acid type. Shallow cycle lead-acid batteries, such as those used in cars, are not recommended for solar power systems, since they do not tolerate repeated heavy discharging, and are quickly damaged in these conditions. There are several types of deep cycle batteries, such as flooded, gel and absorbed glass mat (AGM). Each of these has different advantages and disadvantages, such as durability and lifespan, the level of maintenance required, whether or not they produce gas during operation, and of course price.
Prices of solar panels in South Africa
The price of solar panels in South Africa depends very much on the amount of electricity required, the type and make of panel, and various other factors such as how the panel is to be mounted or integrated into a building. Some stockists display prices online while others only provide quotes on request. For an idea of prices in South Africa, Sustainable.co.za, which regularly features special offers and discounts and sells a wide range of sizes and types of panels, is selling their smallest rigid panel (10W) for R350 (prices correct as of 9 February 2011). Their biggest rigid panel (250W) costs R8 850, and their biggest flexible solar panel (136W), which is recommended for camping, costs R9 990. A full camping kit including the latter panel and all necessary peripherals costs R12 340. They also sell rigid panel kits, including batteries, a charge controller, which protects the batteries from over charging and excessive discharging, and an inverter, which converts the DC power stored in the batteries to AC power. A kit containing a 120W panel costs around R9 250, while a kit that would produce 1kWh per day costs about R12 500.
Where to get solar panels in South Africa
There are now several suppliers of solar panels in South Africa. Among them are Sustainable.co.za, K G Electric, Sinetech, GW Store, Safrelec, The Solar Company and Gener8. They generally import their products from overseas (although some may be assembled in South Africa), and offer a range of sustainable energy solutions, including all the peripherals required. Most of them offer the option of DIY installation or their own installation service. The amount of information available on their websites varies from site to site, as does the range of products they offer. Some, such as Safrelec, may be acting more as wholesalers than retailers, geared for the construction industry rather than individual customers. Their web addresses and more info can be found under Solar Power Companies.
Good Idea Creative Services: http://www.goodideacreative.com/spsample.html
Free Sun Power: http://www.freesunpower.com/batteries.php