By David Jansen
22 January 2018
2017 was the biggest year for new solar installations since the shiny little panels were first invented. Great!
But is it right for you? In a new series of articles written not by boring old us but by superstar Energy Locals solar customers, you can get all the advice you need.
First up, David Jansen looks at the best way to navigate the initial research and purchase of a new system.
The cost to install solar for your home has never been more affordable. The only problem for those people just starting to look into solar is that there are so many confusing contradictions and deals out there, it can be very difficult to get one’s head around it.
As with most deals in life, if it is too good to be true then it probably isn’t the deal to go with because there are unscrupulous installers out there. First thing you need to do is understand what your usage is. This can be difficult for those without a “smart” meter because the information you receive is not granular enough (think of the information you get on your electricity invoice).
If you have a smart meter your retailer can either provide hourly or half hourly intervals of usage (and, when you get solar, your Feed-In-Tariff (FiT)). If you have access to interval data, you can determine how large a system to buy. Another way is to buy a monitoring product to determine your usage. The downside is that these normally need to be installed by an electrician and can report different usage to your ‘official’ meter, but will give you an idea with regards to usage patterns including time of day data.
Some people start out small and expand, but most people will agree that maxing out what you can afford taking into account cost and roof space. In some areas of the country, the Electricity Distributor will restrict the amount that can either be installed or the amount of power going back into the grid (FiT). Maximising the amount of solar also will help pay for your system early via the money earned through the FiT.
It is normally best to go with an installer that is locally based and will support your installation after final payment has been received. Check out the local installer and look for evidence of happy customers. Not sure where to start? The following sites are recommended and continually provide valuable information:
whirlpool.net.au (sign up and get access to the Lounges area, specifically the Green Tech space – there are people with their own agenda but most people are there to help)
solarquotes.com.au (a place to get a few quotes but also a place to get information)
solarquotes.com.au/blog (they will email you titles of articles for your reading pleasure)
Just like car tyres all look pretty much the same from a distance, they vary in quality, cost, performance and longevity. Solar panels are no different.
Look for tier 1 panels. This is a term that’s used in the energy industry to describe good quality panels supported by a warranty that is worth something. A warranty is only as good as the company that provides the service for that warranty though, whether it’s the manufacturer or installer, and you need to be concerned enough to take into account both.
There are basically two common types of panels made of either polycrystalline or monocrystalline cells. The pros of polycrystalline panels are that they are generally cheaper for the same wattage rating, the cons is they are larger and less efficient in very hot conditions. The pros and cons of monocrystalline are just the opposite (I won’t go into all the differences, they aren’t significant but Google is your friend if you want to become an expert and new types are constantly being added).
There will be different power ratings for the panels. Older panels were capable of generating less power than those available today, but the current generation still have various power ratings – it is usually the efficiency that’s improved. And of course, they vary in cost depending on the quality and power that they generate.
Orientation and slope of your roof space needs to be taken into account when designing a solar system. Ideally the orientation is due north, but this isn’t always the case. A term called Azimuth will be mentioned by your installer, which is the degree to which your roof faces north (an example is a roof facing 10 degrees has an Azimuth of 350 degrees). If you don’t have enough north-facing roof space for the size of system you need, then you can also mount them facing either east or west (south facing is the worse and in some cases won’t make sense on the ROI (return on investment). If you have “split” your system east and west, it will complicate the design and reduce your power generation.
Depending on the slope of your roof, you need to be concerned on what the panels will be mounted on to get the best result from your panels. If you have a “flattish” roof, then the best thing to do is to mount them on racks that are tilted. The best site I’ve come across to explain this better is:
Not quite. There’s a really important final piece, and that’s the inverter.
The inverter converts the DC power that’s generated by your solar panels into AC power (power that you use in your house, unless you are off-grid). One thing you need to keep in mind with solar, it will only generate power when the grid is available (excluding off-grid or battery backup systems), so during a grid (electricity) outage solar usage will be shutdown.
There are really only two different types (but large variances of capabilities) of inverters: string and micro. There are pros and cons for each.
String inverters describe the way they are connected to panels, i.e. there is a string of panels per inverter. The pro for this is summed up as a cheaper way to go. The con is that the maximum power converted by the inverter is determined by the least performing panel, so if you have a panel that is faulty, dirty or shaded it will impact the power converted from all panels on that string. Also, the inverter normally at a minimum needs to be shaded to protect the inverter from overheating and burning out eventually.
Microinverters are small inverters and one is attached to each panel, so they can do the conversion of DC to AC power individually. The pro is that every panel operates at the highest possible efficiency, so if you have shading or split between orientations they might be the way to go. The con is that microinverters are usually more expensive to purchase.
Like the panels mentioned above, tier 1 inverters are the way to go.
There will be different articles in the future that explain how to get the most out of your solar system via monitoring your usage, and a discussion on batteries. For now, if you haven’t yet got solar then the continued increase in grid energy prices and the ongoing decline in the cost of solar make it a no-brainer for millions more people than those who currently have it. Thinking of going for it? Use our handy checklist to get started:
This article was written by an Energy Locals customer, David Jansen, who's an expert in all things solar and we're very grateful for his help. David has no affiliation to or interest in Energy Locals.