FAQs

How do I make my home more energy efficient?How can I tell what kind of bulbs I have?How do I calculate my wattage use?How do I know what size TV I have?What size solar and battery do I need? How do I calculate that?Why do I need a controller?What size controller do I need and how do I calculate it?What size inverter do I need and how do I calculate that?How does a controller and inverter work together?If the inverter breaks after 6 months, how do I return it?How do I protect the battery?How do we determine what number of panels and batteries to run in series? What is optimal?

1. How do I make my home more energy efficient?
   Making your home energy efficient is the first step towards reducing your electricity bill. With some small changes come big savings.
   • Change to LED bulbs.
     LED bulbs use a startling 80-90% less energy.
     Old 60W bulbs use 110W of electricity. Only 60W is emitted as light and the remaining 70W is lost into the air as heat. A 9W LED bulb is the equivalent brightness to an old 60W bulb and is ten times more efficient and cost effective.  You will quickly recover the cost of replacing your old bulbs. The difference in the required energy is staggering.  Compare these two tables: 

     	Energy used in 1hr	Energy used in 8hrs	Solar system required
     1 x Old 60W	110W	880W	1 x 260W panel1 x 200Ah battery
     10 x Old 60W	1100W	8800W	8 x 260W panels8 x 200Ah battery

      

     	Energy used in1hr	Energy used in 8hrs	Solar system required
     1 x 9W LED	9W	72W	1 x 15 W panel1 x 12Ah battery
     10 x 9W LED	90W	720W	1 x 150W panel1 x 120Ah battery

      

   • Change TVs to LED TVs
     Most new models are LED.  Plasma  and LCD TV’s are less energy efficient than a new LED TV
   • Change to energy efficient fridges
     Old fridges are not as well insulated as new energy efficient fridges and the compressors in the old fridges are old technology

     	Energy consumption	Cooling time in 24hrs	Total power consumption per day
     Old fridge	125W	12hrs	1500W hours or 1.5 Escom units	1 x 300W panel2 x 120 Ah battery
     Energy efficient fridge	125W	6hrs	750W hours or 0.5 Escom units	1 x 150W panel1 x 120 Ah battery

     Click here to calculate your energy needs.

2. How can I tell what kind of bulbs I have?
   As a general rule, the old ones are see-through and emit yellow soft light. However this is not always the case. If in doubt, use the Escom exchange “old for new scheme” or buy new.  There are coiled fluorescent energy saving bulbs on the market which are not LED and use twice as much energy as LED bulbs. Good quality LED bulbs last for 25,000 hours, or up to 10 years.
3. How do I calculate my wattage use?
   Most appliances have stickers with their technical specifications written on them.  Write down the watts of each of the appliances that you use. Multiply the watts with the amount of hours you use that appliance each day. Total them together and you have your wattage use.  Please refer to our energy calculator to assist you. 

   Utility	Quantity	Watts per hour	Hours used a day	Total Watt hours (Wh)
   Lights	5	9	8	360
   Laptop	1	65	3	195
   Smartphone	1	5	2	10

   Total: 565Wh

   Click here to calculate your energy needs.

4. How do I know what size TV I have?
   The screen size of a TV is measured diagonally.
   Types of TV’s:
   a. LCD(liquid crystal display)
   b. LED – (light emitting diode).
   c. DLP (digital light processing)
   d. Plasma which use significantly more energy

 

Size of LED TVs	Range of watts used per hour
17”	40-70
21”	50-80
32”	100-120
50”	100-150

5. What size solar panel and battery do I need? How do I calculate that?
   First of all calculate your wattage use. (see FAQ 3)
   To generate 500Wh of power per day with an average of 5 hours sunlight one 100W panel is the minimum number of panels required.This is calculated thus:  500Wh/5 hours = 100W of solar energy needed. To keep the life span of the battery, the industry recommendation is to discharge the batteries only to 50%, thus the battery capacity has to be doubled:500Wh x 2 = 1000WhThe batteries need to store 1000Wh of energy. This is calculated by dividing the Watt hours by the voltage of the battery.  In this example we are using a 12V battery. 1000Wh/12V = approx. 80AhClick here to calculate your energy needs.
6. Why do I need a charge controller?
   The controller regulates the voltage from the solar panel(s). The amount of electricity a solar panel produces will vary enourmously depending on the amount of direct, cloud free sunshine it gets.
   The charge controller functions as a voltage regulator, converting the energy from the solar panels to the batteries at the correct voltage level. The controller also protects the battery from overcharging and from discharging less than 50% so the battery lasts longer.There are two different types of charge controller: PWM and MPPT
   PWM is cheaper but less efficient.  An MPPT increases efficiency by 30%
7. What size controller do I need and how do I calculate it?
   Solar panel size/ battery voltage (usually 12V) = size of controller.e.g.: 100w panel/12 volts = 8.3AThis figure is rounded up or down to the nearest available charge controller. This is only a rule of thumb.  In this case a 10A controller would work.For a 255W panel/12V = 21.25, a 20A controller will work.
8. Why do I need an inverter?
   Solar energy creates DC (Direct Current) electricity which is stored in the solar batteries.  The appliances that you plug in at home or work run on AC (Alternating Current) which has an output of 220-240V.  Think of your inverter as a converter of DC electricity to AC electricity.
9. What size inverter do I need and how do I calculate that?
   Inverters come in different sizes: 100W solar only – 100KW grid tied inverter. In very general terms the size of an inverter can be calculated by working out the electrical load (in watts) that you wish to use all at once. If it is just for lights, phones laptop, TV, radio the calculation is very straight forward:10 x 5 LED lights at 10W each (10W x 5 = 50),
   1 smart phone = 7.5W
   1 basic phone =5W
   1 laptop = 65W
   1 LED TV = 100W
   TOTAL 227.5W
   For this scenario a 300W inverter would be enough.  To maintain the condition of your inverter it should not run at its highest level all the time. Therefore you would choose a larger inverter than your exact load requirements.

   Anything with that heats or cools uses a lot more energy like a kettle or oven, or hot plate uses a lot of energy.  Unless you have a budget for a big system it is best to use alternative heating methods.

   Anything that has a motor or compressor like a fridge, air con, borehole pump, washing machine will all generate massive surges.   This must be considered when choosing an inverter.

   If your inverter is too small, it can be damaged during a surge. It is best to seek advice from a trained solar engineer for advice on your unique needs.

10. What happens if something goes wrong?
    All our products are valid for one year and our installations for two years. If we can’t fix we’ll replace it.
11. How do I protect the battery?
    The charge controller protects the battery from overloading.Do not disable the charge controller or your battery will not last.The inverter should protect the batteries from under voltage and wil shut down if the voltage in the batteries gets too low.If there is no inverter for instance in a 12V system which would run small DC appliances the load should be connected directly to the charge controller then the charge controller takes over the charge protection of the batteries.
12. How do we determine what number of panels and batteries to run in series? What is optimal?
    Everything has to match – the panel number has to match the battery capacity and the amount of sunshine hours and the battery capacity has to match the to the charge controller and the controller to the batteries.
13. Why is cable size important?
    The cable diameter has to be in relation to the voltage and amps.  (Watts = Amps x Volts)
    DC systems always require thicker cable because the voltage is low.
    AC systems require thinner cable because there is higher voltage and lower amps
14. What is the lifespan of a panel?
    The manufacturer gives a 10 year warranty on workmanship and 25yrs warranty on performance output.  This means that panels should have 80% performance by year 25. A good solar panel manufacturer will have these standards approved by independent external certification body for example TÜV  or IEC.  Certificates from these bodies are the highest approval within the solar industry.  Team Planet chooses only manufacturers with either of these certificates.
15. Once I buy this system, can I upgrade it if I want more power?
    If you think you would like to expand your system as your budget or requirements evolve it would be wise to explain that to your solar designer so that he can advise you on the most flexible system for you to grow into.
16. Six good reasons why I should choose Team Planet for my installation?
    1) All our system are carefully tailor made to the individual needs of our customer.
    2) We perform thorough on site visits for installations
    3) We offer 2-yr warranty on all our installations.
    4) Our team of MERA qualified electricians were trained by a TÜV certified solar designer
    5) We source only the highest quality products at the best possible price.