Q1: What type of wire/cable is most suited for solar work
A1: Best cable or wire to use for Solar installations is that which is multistranded and for cable from the PV array, multistrand, tinned copper. Cables that will be exposed to the elements need to have a proper silicon and if possible polyurethane shrouding around the cable to insulate as well as isolate the cable.
Remember, heat is not DC's best friend!!!!
Q2: What is the cable thickness required for solar panels
A2: Usually the cable employed to connect up panels in series is of the 6mm gauge. Cabling from the panels to the MPPT will vary depending upon whether it is a High Volatge grid Tie system or a lower voltage DC integrated system. Refer the Sunbusters wiring chart on our website.
Q3: What is the best method of connecting up solar cables
A3: Preferable you should not really connect up wires as it is always a potential for another loose or poor connection. However, if you find you have to extend wiring for any reason (e.g. poor planning!), then use a ferrule type connection and crimping tool suitable for the task.
Q4: Is a wind turbine a better option than a solar system
A4: It can be, depending upon where you are located. If you are in an area where there is a lot of cloud with a lot of consistent medium to light winds, then, yes, a wind turbine might well be a better option. However, wind is much more fickle than the sun in SA, and you can get days without any wind to speak of when you will require Mains or a Genset to support you. A Hybrid system in windy areas is a good option where you get the consistency of solar coupled with the bonus of a wind turbine’s output.
Q5: Do I need protective tubing around my solar wiring from panels to regulator
A5: We prefer to see ‘loomed’ wiring and the correct tubing also acts as an extra protective layer against the strong SA UV rays. Many installations are done without tubing though and as long as the wiring is well protected behind panels and other shaded areas, then it might not be critical.
Q6: When do I require junction boxes
A6: If you have several strings of panels, then it stands to reason that your regulator, or MPPT, will not be able to accommodate all these various wires. In this case you will need to use a Junction box to connect up all the wires and feed out into 2 wires to your MPPT. Grid Tie Inverters usually have the facility to have multi-input connections which then makes junction boxes redundant.
Q7: What fusing is required for solar system
A7: A much-debated topic that is now being addressed by the various associations responsible for setting standards on AC wiring. On the DC side, we recommend adequate fusing between:
A. Panels and MPPT
B. Inverter and Battery bank
Q8: Do I need a COC when adding a solar system to my DB board
A8: You should always ask for a Certificate of Compliance for any AC electrical work conducted on your DB board as this is a guarantee of professional workmanship and will also be required by your insurance company. You will also require this as part of any submission for getting authority to feed back into the grid.
Q9: Is it best to install a separate dedicated DB board for my solar system
A9: That is a personal decision, and will also depend upon whether your system is the main supplier of power, or representing only a small portion of your overall power requirements.
Q10: Can I feed back into the grid using an old analogue (spinning wheel type) meter
A10: Yes, that is possible, but usually requires permission from your local electricity supplier
Q11: Is it better to have a dedicated solar geyser, or run it off a solar eletrcial system
A11: Again, there is a difference of opinion on this, but the majority appear to favour dedicated solar water-heating systems rather than trying to run it through a ‘normal’ solar system because of the much bigger inverters you would require to run the geyser(s) which can make it less cost effective. It is useful to have your normal solar system acting as a temperature booster for those cold winter nights, however!
Q12: Do heat pumps work well with solar
A12: heat pumps can pull quite a bit of power, but are frequently integrated into solar systems. They do have mechanical working parts which is frowned upon by many solar ‘purists’ who prefer solar geysers to heat pumps.
Q13: Are trackers really worth the money
A13: In the days when panels were much more expensive, there was a very good case for using trackers to increase solar yield. However, these days with panels being so cheap, you could only really justify using trackers if you were short of space.
Q14: Is it worthwhile solarising a pool pump on its own
A14: As a rule, it is rarely viable just to solarise a pool pump on its own due to the large consumption of between 3-5Kwh the average pool pump requires, coupled to the large Inverter to cater for the start-up current . employing good quality components and including installation, you could expect to pay in excess of R50,000.00 for such a system
Q15: Can solar panels be used to heat water
A15: The flat panels one sees on people’s roofs that heat geysers, or pools, are different from normal PV panels designed to generate electricity. However, there are moves to make a 2-in-1 panel that could be cooled by water to increase efficiency and whilst heating the water as it cools the panel, directing it back to the geyser – how’s that for efficiency?!!
