Make sure you only buy Tier One Solar Panels. Tier One is a rating provided by Bloomberg Financial for meeting a set of criteria, the main one being the bankability of the manufacturer. These panels are installed en-masse accross massive solar farms. The manufacturers of these panels are vertically intergrated & invest heavliy in R & D. They use advanced robotic techniches to manufacture the panels and have been manufacturing for more than 5 years.
Choose the best inverter you can afford but most importantly choose one with good local support. We have had good support with warranty claims with Samil inverters & excellent support from Suntellite. We predominantly now use Solax inverters whose parent company is Suntellite which we have been dealing with since 2011. To date we haven't had to process a warranty claim for Solax or SMA inverters but when we do I'm sure that it will be handled effeciently.
Only accept a quote from a company after a site visit by a Clean Energy Council Accredited Designer or Installer. Most systems in Australia are sold by sales people with no qualifications and in some cases they just won't work effeciently. Some systems are sold over the phone using software such as Google Earth and Nearmaps. It's not always possible to tell if a system will be shaded from trees or chimneys etc using software from a remote location. See the picture above showing panels installed on the southern side of the chimney. The performance of this system would be horrendous.
One of the questions people often ask is what size system should they buy? Having a solar system which allows you to consume most of the energy that it produces can have a return on investment of as little as 4-5 years. The problem with this is sizing a system for your current daytime self consuption is that electric cars are here now and are going to be very popular. I love the idea of using the excess energy from my roof to charge an electric car battery. In addition to this batteries for household consumption will be more affordable in 2-3 years time.
Don't fall for anyone telling you exactly how much you will save on your electricity without first monitoring your energy useage. Even recently I've heard claims from other companies that by installing a solar power system you won't have any electricity bills. Remember the excess power you produce is sold to the grid at 6.6 cents per KWH and at night you could be paying as much as 26 cents per KWH. For this reason you should load shift as much as possible your appliances to run during the day when your solar system produces power. This way you are saving 26 cents per KWH instead of selling it for 6 cents per KWH. Some appliances such as dishwashers & washing machines have delayed start features which help to acheive this.
Buy from a company that will give you good local support and an installation that meets the standard. See picture above by one of the largest solar sales companies in Australia. Exposed cables are not only a trip hazard but fail to meet several points of the standards. Mainland companies often install systems using mainland installers. It can be difficult to hold them to account when there is a problem with your installation.
Watch out for high pressure sales people who pressure you into signing a contract right now. Be even more careful of those saying that the rebate is about to end.
The rebate will be reduced on the 1st of January but only by a margin. Take your time and make an informed decision.
Don't settle for an averaged system performance estimate. Many companies simply tell you that the system will produce an approximate ammount less any shading. This is done by multiplying the size of the system by 3.5 peak sun hours - thats it!
At Affordable Solar Tasmmania we take into account the orientation & pitch of your roof, the cabling losses as well as the losses due to shading using the Solmetric Suneye-210. This hand-held electronic tool measures the available solar energy by day, month, and year with the press of a button by determining the shading patterns of a particular site. The award-winning SunEye incorporates a calibrated fisheye camera, electronic compass, tilt sensor, and GPS to give immediate measurements in the field
Batteries are now available and there is a lot of buzz in the industry about them. I haven't yet seen a case for them which makes financial sense.
My own analysis (October 2016) of the Tesla Powerwall return on investment when connected to Aurora's tariff 31 indicates a 22 year return on investment. They are warranted for just 10 years. This is based on being able to charge & discharge the battery to its capacity once per day which may not always be possible. Tesla have since released details of the second generation of their Powerwall. To their credit the return on investment has halved but again that assumes that you are able to charge & discharge the battery to its capacity once per day which may not always be possible. The return on investment is now around 10 years.
Rather than installing batteries now I encourage people to be battery ready. With inverters such as the Solax SK-TLE which with the addition of a charger unit batteries can be added quite easily. Batteries are expected to fall significantly in the next two to three years.